Tragopogon miscellus Ownbey, Moscow salsify [31,115]
Tragopogon × crantzii Dichlt. [62,150]
Tragopogon mirus Ownbey, remarkable salsify [31,115]
Moscow salsify is the name used for yellow salsify ×
Jack-go-to-bed-at-noon (Tragopogon lamottei)
hybrids that occur in parts of Washington, Idaho,
Montana, and Wyoming . Tragopogon × crantzii is
the name used for yellow salsify × Jack-go-to-bed-at-noon
hybrids in the Great Lakes area [62,150]. Remarkable
salsify is the yellow salsify × salsify (Tragopogon
porrifolius) hybrid. These hybrids are possible anywhere
the distributions of parent species overlap [31,115]. For
more on goatsbeard (Tragopogon spp.) hybrids, see the
following references: [38,110,115].
for Tragopogon dubius:
Tragopogon dubius subsp. major (Jacquin) Vollman 
Tragopogon major Jacq. 
FEDERAL LEGAL STATUS:
Information on state-level noxious weed status of plants in the United States is available at Plants Database.
Throughout most of its range, yellow salsify is described as infrequent, occasional, locally common, or scattered [17,56,63,123,155,159]. There are also reports of yellow salsify as common and widespread (Mahler 1988, as cited in ),[74,104], and large populations are reported from the southern Kootenay, Thompson-Nicola, and Okanagan regions of British Columbia .
According to a review by Clements and others , yellow salsify was introduced
to North America as a garden plant in the early 1900s. Spread was likely from east
to west, as this is was the pattern in the Pacific Northwest .
provides a distributional map of yellow salsify and its hybrids.
HABITAT TYPES AND PLANT COMMUNITIES:
Given a seed source and a canopy opening, yellow salsify is a potential inhabitant of nearly any vegetation or community type. It has been described on open beaches and in grasslands, shrublands, woodlands, and coniferous forests throughout North America [63,77,78,79,148,160]. Yellow salsify is common in abandoned agricultural fields and many studies have been conducted in this environment. Throughout this review, the age of old fields refers to time since abandonment or time since last cultivation. For example, "1-year-old fields" have been out of cultivation or left fallow for 1 year.
Disturbed areas are typical yellow salsify habitats, but in open forests and woodlands, shrublands, and grasslands yellow salsify may be persistent. In a survey of disturbed sites in Yellowstone National Park and the adjacent Gallatin National Forest, yellow salsify occurred on roadsides and in clearcuts, but abundance decreased from disturbed sites to the forest interior . In Glacier National Park, yellow salsify occurred adjacent to roadsides but not at sites 7 feet (2 m) into intact rough fescue-Idaho fescue (Festuca altaica-F. idahoensis) grasslands . However, yellow salsify was 1 of 3 nonnative species noted in remote, open, old-growth ponderosa pine (Pinus ponderosa) stands in Grand Canyon National Park, which were closed to grazing and protected from logging by the mid-1930s .
While often frequent in disturbed or open habitats, yellow salsify rarely occupies much of the total vegetation cover, regardless of the habitat type or disturbance regime. Yellow salsify was the second most frequent nonnative species in Utah's Grand Staircase-Escalante National Monument, but average cover was less than 1% . In a survey of disturbed sites in Utah, yellow salsify occurred on just 2 of 7 disturbed sites, and maximum average cover on the sites was 0.01% .
© Br. Alfred Brousseau, Saint Mary's College
GENERAL BOTANICAL CHARACTERISTICS:
This description provides characteristics that may be relevant to fire ecology and is not meant for identification. Keys for identification are available (e.g., [42,47,56,57,85,150]). Yellow salsify hybrids are described in a review by Clements and others .
Yellow salsify grows as an annual, biennial, or monocarpic perennial [25,51,56,106,121]. Plants grow between 12 and 39 inches (30-100 cm) tall [47,155]. In its first year(s), yellow salsify produces an erect rosette of grass-like leaves. Plants may remain vegetative for up to 10 years before flowering. After flowering, yellow salsify dies [25,51].
Yellow salsify produces ascending, leafy, and sometimes branched stems that exude a milky latex sap when broken [7,56,121,123]. Alternate leaves are narrow, measure 0.4 to 12 inches (1-30 cm) long, and are tapered from base to tip [35,107,121]. Young leaves can be hairy , but mature leaves are waxy . Head flowers occur at the stem ends on inflated peduncles . Heads measure up to 2.2 inches (5.5 cm) in diameter and are comprised of only ray flowers [121,145]. Flowers open early in the day and close by early afternoon and may not open during cloudy or rainy days [74,121].
|Yellow salsify produces achenes that measure 1 to 1.6 inches (25-40 mm) long. Achenes are attached to a large feathery pappus that may reach 4 inches (10 cm) in diameter at maturity [12,44,57,121]. When achenes mature, the base of the flower reflexes, forming a dandelion-like ball of fruits [35,47]. Seeds produced in abandoned fields in Michigan weighed an average of 6.5 mg . Seed placement within the flower affects its weight; mass gradually increases from the center to the periphery of the flower head [88,94].|
© Kenneth Chamberlain, Ohio State Weed Lab Archive, Ohio State University
|Yellow salsify taproots are described as stout, fleshy, thick, and long [44,47,107,145]. On disturbed sites in Utah, yellow salsify roots were often "heavily" infected with mycorrhizae . As of this writing (2008), no excavation studies reported taproot size or rooting depth for yellow salsify rosettes or flowering plants.|
© Michael Shephard, USDA Forest Service, Bugwood.org
RAUNKIAER  LIFE FORM:
Yellow salsify reproduces solely by seed .
Pollination and breeding system: Yellow salsify produces perfect flowers [47,155]. Self pollination and cross pollination are possible [25,28]. Yellow salsify flowers on the Palouse Prairie of Idaho and Washington were visited by a variety of generalist bees and flies (Cook, personal observation, cited in ).
Seed production: Generally yellow salsify is highly fertile; typically 97% or more of its flowers produce fruits . Flower and seed production can be affected by rosette size, temperature, day length, season, time since last disturbance, herbivory, and predation.
In eastern Washington and western Idaho, yellow salsify plants averaged more than 100 ray flowers/head . In old fields in Michigan, yellow salsify produced an average of 90 seeds/plant . In an abandoned pasture in Peterborough County, Ontario, plants produced 35 to 88 seeds/flower head . In the foothills above Salt Lake City, Utah, yellow salsify produced 1 to 14 flower heads and 20 to 127 seeds/head . In North Dakota, average-sized yellow salsify produced 150 seeds in outer flowers and 330 seeds in inner flowers. Seeds produced by outer flowers were heavier than those from inner flowers, but seed weight did not affect germination. The study plant in North Dakota produced just 5 flower heads .
Seed production may be greater from larger plants, during long days, and in very early-seral habitats. Probability of yellow salsify flowering increased with increased rosette size in old fields in Michigan. The minimum root crown diameter for flowering was 0.11 cm. The maximum probability of flowering was 0.87 for plants with a root crown diameter greater than 0.7 cm; however, flowering probability decreased when rosette diameters exceeded 0.7 cm. Yellow salsify plants grown in a greenhouse failed to flower although they surpassed the minimum root crown diameter required for flowering. A vernalization period may be required for flowering in temperate climates [48,51]. Day length can also affect yellow salsify flowering. Flowering increased with increasing day lengths from 10 to 14.5 hours. As day length decreases, yellow salsify is more likely to remain a rosette and potentially delay flowering to the next year . For yellow salsify populations near Salt Lake City, Utah, the number of seeds produced/flower head decreased significantly (P<0.01) as the season progressed . In old fields in southwestern Michigan, yellow salsify seed production decreased with increasing old field age. The 3 flowering yellow salsify in 15-year-old fields produced an average of 73 seeds each. In 1-year-old fields, 21 yellow salsify plants flowered and produced an average of 127 seeds each .
Herbivory/predation: Effects of herbivory on yellow salsify are variable, but the presence of seed predators will reduced the number of yellow salsify seeds. In an old field in Minnesota's Cedar Creek Natural History Area, researchers simulated herbivory on yellow salsify leaves and roots. Treatments included leaf removal of 25% and 75%, root removal of 25% and 75%, and leaf and root removal of 25%. Flower production was greatest for control plants and least for any treatments involving root removal. Plants with 1 or more flowers removed by herbivores, primarily white-tailed deer, were larger and produced more flowers than those without flowers removed, regardless of the simulated herbivory treatment . In the Bison Flats area of South Dakota's Wind Cave National Park, yellow salsify was one of the most important pronghorn forages in 1 of 2 observed feeding years. By late summer, some plants lost up to 6 flower heads . Pronghorn and deer are not the only yellow salsify herbivores. For more on this topic, see Importance to Wildlife and Livestock.
Predation on yellow salsify seeds can be as high as 100%. Presence of neighboring vegetation has been shown to affect predation rates, but not consistently. In southwestern Michigan old fields, 73% of yellow salsify seeds were removed within 24 hours when dishes of seeds were randomly arranged . In a 10-year-old southwestern Michigan old field, more yellow salsify seeds were removed from undisturbed than disturbed sites. In plowed fields, areas of small disturbances, and in undisturbed vegetation 3.1%, 5.5%, and 8.4% of seeds were removed/dish/day, respectively. Through comparisons of visual evidence at feeding sites and during controlled laboratory studies, researchers concluded that deer mice were the primary seed predators. At most feeding sites, there were seed coats present, suggesting that seeds were not cached. Predation patterns were patchy and once a feeding source was located it was exploited, which may allow for pockets of seed survival and a patchy distribution of seedlings on the landscape . However, if seeds do not germinate rapidly, seed predation may exceed 95% regardless of the presence of neighboring vegetation. In old fields abandoned for 20 years or more near Guelph, Ontario, yellow salsify seeds glued to fish line were left available to predators for 10 months. After this time, 95% of yellow salsify seeds were removed in areas with intact vegetation, and 100% of seeds were removed in areas of cleared vegetation .
Seed dispersal: Yellow salsify achenes break easily from the flower and can travel long distances in the wind . Under controlled conditions, yellow salsify achenes had a slow descent velocity, which relates to a high potential dispersal ability . While 65% to 90% of yellow salsify seeds typically fall within 16 feet (5 m) of the parent plant, seeds may travel more than 820 feet (250 m) in upward wind gusts . On the tallgrass Cayler Prairie in Dickinson County, Iowa, yellow salsify seeds were found "several hundred meters" from the nearest parent plant . In the South Platte River Basin of north-central Colorado, 12% of all seeds caught in aerial seed traps were yellow salsify or dandelion (Taraxacum officinale). Yellow salsify seeds were not collected from samples taken from the water or channel bed, suggesting that dispersal in water is unlikely .
Dispersal of yellow salsify seed by animals was not mentioned in the available literature. Dispersal in fur or feathers is possible, and if seeds survive passage through the digestive tract, dispersal through animal waste is possible as well. A large variety of animals feed on yellow salsify flowers and seeds. For more on this, see Importance to Wildlife and Livestock.
Seed size, plant height, and neighboring vegetation can affect seed dispersal. For populations of yellow salsify in foothills above Salt Lake City, pappus radius decreased significantly (P<0.01) over the season. Although the pappus area was larger on heavier seeds, heavier seeds had a lower dispersal potential than lighter seeds. Seed release height may, however, compensate some for the dispersal of heavy seeds, since flower heads producing heavier seeds occurred higher above the ground than those producing lighter seeds (P<0.001) [93,94]. In a controlled wind tunnel experiment, as the height of neighboring vegetation increased the number of yellow salsify seeds dispersing beyond the neighboring vegetation decreased (P<0.01). Increased wind speeds and increased release distance from established vegetation, however, increased the percentage of seeds dispersing beyond the established vegetation .
Seed banking: Yellow salsify does not produce a large and/or persistent seed bank. Successful establishment and persistence of yellow salsify populations depends on the dispersal and germination of newly produced seed (Qi and Upadhyaya, unpublished data, cited in ),. Seeds do not likely survive more than 1 to 2 years in the soil . In a controlled study, yellow salsify seed germinated the first year soil was left fallow but did not germinate in any of the following years when soil was cultivated. The researcher concluded that yellow salsify seed dormancy is typically less than 1 year . Yellow salsify seeds did not germinate after 3 or more months in the water of Washington's Chandler Power Canal. After 60 months of dry storage, yellow salsify seed germination was 55% .
A low density of yellow salsify emergents or seeds was recovered from grassland, shrubland, and forested sites in the Greater Yellowstone Ecosystem and British Columbia. A maximum of 13 yellow salsify seedlings/m² emerged from unburned soil samples collected in Idaho fescue/bluebunch wheatgrass (Pseudoroegneria spicata) habitats in Yellowstone. Although present in the aboveground vegetation, there were no yellow salsify emergents from burned or unburned soil samples collected in bluebunch wheatgrass/Sandberg bluegrass-needle-and-thread grass (Poa secunda-Hesperostipa comata) or subalpine fir/pinegrass (Abies lasiocarpa/Calamagrostis rubescens) habitats. For the effects of heating on soil-stored yellow salsify seed, see Plant response to fire . In ungrazed to heavily grazed sites dominated by antelope bitterbrush (Purshia tridentata) in British Columbia's Okanogan Valley, the density of yellow salsify was 9 plants/m² in aboveground vegetation, and 1.8 seeds/m² were extracted from soil samples. Soils were sampled from 24 May to 4 June , which likely preceded substantial yellow salsify seed dispersal.
Germination: Yellow salsify seeds germinate best in moderate temperatures (59-72 °F (15-22°C)) [88,122], in full light conditions , and with burial in litter or soil up to 0.8 inch (2 cm) deep [49,122].
Yellow salsify seed dormancy is variable. Yellow salsify seeds collected from old fields in Michigan required 60 days of afterrippening to germinate in controlled conditions . Upadhyaya and others  also reported short-term primary dormancy; however, yellow salsify seeds collected from an abandoned pasture in Peterborough County, Ontario, germinated at over 90% immediately after harvest . Secondary dormancy in yellow salsify seeds can be induced by low-oxygen environments . Anaerobic conditions induced secondary dormancy in yellow salsify seeds collected from the Canoe and Williams Lake areas of British Columbia. After 3 to 4 days in deaerated water, almost no seed germinated. Stratification treatments successfully broke the secondary dormancy. After 12 days in water, yellow salsify seed viability was lost .
Studies have shown that germination of yellow salsify decreases with extreme temperatures, increased depth of burial, decreased light availability, and with established vegetation and litter. Seed size and moisture did not restrict germination.
The optimum germination temperature for yellow salsify seeds collected from British Columbia's Canoe and Williams lake areas was 59 °F (15 °C). Seeds did not germinate at temperatures of 41 °F (5 °C) or 86 °F (30 °C). Seed exposed to 41 °F (5 °C) retained their viability, but those exposed to 86 °F (30 °C) showed high levels of decay. Emergence was 80% for seeds planted 0.8 inch (2 cm) deep; no seedlings emerged when planting depths exceeded 2 inches (5 cm). Seeds at 3 inches (8 cm) deep germinated but failed to emerge . Dark conditions decreased germination, and seed size did not affect germination of yellow salsify seeds collected from populations in Michigan and/or Ohio .
|Germination of small, medium, and large yellow salsify seeds in dark and light conditions at 25/15 °C |
|Seed size||Average weight
|Germination in light
|Germination in dark
Germination rates of over 90% were obtained from yellow salsify seeds collected from old fields in Peterborough County, Ontario, immediately after and up to 2 months after seed harvest in late June or early July. Seeds were kept at 72 °F (22 °C) and given 16 hours of light. Seed size and moisture conditions did not affect germination .
|Number of yellow salsify germinants and number of days to half emergence in moist, normal, and dry conditions |
(1 day water, 2 days dry)
(2 days water, 6 days dry)
|Number of emergents||16.87||17.33||17.20|
|Days to 50% emergence||9.57||11.87||12.98|
In a greenhouse study, yellow salsify emergence was reduced when both established vegetation and litter were present. Emergence of yellow salsify was greatest in trays with a straw litter cover and lowest in trays with established Kentucky bluegrass (Poa pratensis) and litter. Emergence in established Kentucky bluegrass without litter was similar to that in trays of bare soil. The fate of seedlings in this study is discussed below .
Seedling establishment/growth: Predictions regarding yellow salsify's survival and flowering success can be made from the diameter of its root crown as a rosette [48,51]. Successful yellow salsify seedling establishment and growth, however, are affected by temperature, litter, neighboring vegetation, seed predation, and herbivory. In a controlled study, yellow salsify seedling shoot biomass increased with increasing nighttime temperatures. Seedlings were grown from seed collected in Utah's Uinta National Forest and subjected to nighttime temperatures from 36 to 68 °F (2-20 °C). After 8 weeks of growth, seedling shoots averaged 0.48 g at the highest and 0.15 g at the lowest nighttime temperatures . Moisture conditions in a controlled study did not dramatically affect seedling height or weight .
Probability of yellow salsify survival and flowering generally increase as the rosette root crown diameter increases. A minimum root crown diameter of 0.1 cm was required in the previous year for flowering to occur; however, the flowering probability was low, 0.19, for root crown diameters of 0.1 to 0.3 cm. The maximum probability of flowering, 0.87, occurred when root crown diameters were 0.7 cm, but the flowering probability decreased when root crown diameters exceeded 0.7 cm. The probability of yellow salsify dying before flowering was low, 0 to 0.16, regardless of root crown diameter. Non-flowering plants did not typically die but remained vegetative until the next year. The researcher predicted that yellow salsify could remain vegetative for up to 10 years before flowering [48,51].
Presence of established vegetation has been shown to decrease yellow salsify seedling size and seedling survival in greenhouse and field studies. In a greenhouse study, yellow salsify seedling biomass was greatest in trays with straw litter or with bare soil and lowest in trays with established Kentucky bluegrass. Initial seed size did not substantially affect seedling biomass in trays with established Kentucky bluegrass. Seedling growth in areas with litter or vegetation cover may be better predicted by early seedling weight than seed weight .
|Mean final dry weights (mg after 78 days) of yellow salsify seedlings* in greenhouse trays with differing types of cover |
|Seed size||Ground cover type|
|Bare||Litter||Vegetation||Vegetation and litter|
|*Seedlings were thinned to maximum density of 10 seedlings/tray (19 × 9 × 6 cm)|
In southwestern Michigan old fields, yellow salsify seedling emergence increased but the probability of survival and flowering decreased with increasing old field age. Researchers monitored yellow salsify emergence in seeded and in control plots in 1-year-old, 5-year-old, and 15-year-old fields. Yellow salsify established in open and vegetated patches of 1- and 15-year-old fields. In 15-year-old fields, the average probability of seedling survival was 0.17. The survival probability was greatest, 0.67, on bare ground and lowest on vegetated areas, 0.14. Yellow salsify reproductive output was lowest in the 15-year-old fields, a pattern likely to lead to the eventual local extinction of yellow salsify. Researchers reported that because yellow salsify does not produce a persistent seed bank and relies on seed dispersal to occupy disturbed sites, it is not typical in old fields until 4 to 10 years after abandonment [50,51]. Seed production was also affected by old field age.
|Yellow salsify emergence, seedling survival, and flowering in old fields of increasing age in Michigan [50,51]|
|Emerging seedlings/0.25 m²
|Emerging seedlings/0.25 m²
|Seedling survival probability*||0.24||no data||0.17|
|Proportion flowering||0.46||no data||0.06|
|*No statistical difference in probability of seedling survival in 1-year-old and 15-year-old fields.|
Seed predation affected seedling emergence more than the presence of neighboring vegetation in an abandoned pasture near Guelph, Ontario. When yellow salsify seeds were sown in an abandoned pasture, cages to reduce predation significantly (P<0.05) increased emergence .
|Number of yellow salsify seedlings emerging/1000 seeds sown on sites with and without vegetation and/or predation |
|Vegetation/predation characteristics||Ground cover intact/caged||Ground cover removed/caged||Ground cover intact/no cage||Ground cover removed/no cage|
|Average number of seedlings||800c||790c||20a||89b|
|Values followed by different letters are significantly different (P<0.05).|
Yellow salsify is somewhat sensitive to defoliation and more sensitive to root damage. In simulated herbivory experiments on an old field in Minnesota's Cedar Creek Natural History Area, researchers removed 25% and 75% of leaves, 25% and 75% of roots, and 25% of both leaves and roots. Mortality of untreated plants and plants with 25% of leaves removed were not different; however, all other treatments led to mortality of ≥80% . Information on flower production by experimental plants is available in Seed production.
Vegetative regeneration: Yellow salsify does not reproduce vegetatively .SITE CHARACTERISTICS:
Climate: The ubiquitous distribution of yellow salsify suggests a broad tolerance of climatic conditions. Optimal growing conditions in yellow salsify's native European habitats include long days, cool temperatures, and moderate moisture. In Europe, yellow salsify reaches its maximum abundance between 40 and 50° N latitude . In North America, yellow salsify occurs in similar habitats but also much harsher environments. Yellow salsify occurs on glacial moraine mounds in Powell County, Montana, where microsites can be hot and dry or cool and mesic. In microsites occupied by yellow salsify, soil moisture content averages ranged from 7.2% to 20.3%, and the highest soil surface temperature was 109 °F (42.5 °C) in August . Yellow salsify leaves have a wax coating nearly identical to that of Jack-go-to-bed-at-noon. In a controlled study, the abundance and size of Jack-go-to-bed-at-noon wax crystals increased with soil moisture stress and decreased with decreased light intensity . Yellow salsify may also regulate the size and abundance of its wax crystals to minimize water loss in harsh environments.
Elevation: In North America, yellow salsify primarily occupies habitats at elevations from 30 to 8,200 feet (10-2,500 m) .
|Elevation range for yellow salsify in parts of the western United States|
|State, region||Elevation range (feet)|
Grand Canyon region
|New Mexico||4,500-7,500 |
Soil: Yellow salsify grows on a wide variety of soil types, but likely cannot tolerate saturated or anaerobic soil conditions. Textures from sand to clay loam are tolerated . In central and eastern Canada, yellow salsify occurs on limestone soils . In Park City, Utah, yellow salsify grows on silver, lead, and zinc mine dumps .
Anaerobic conditions induced secondary dormancy in yellow salsify seeds collected from the Canoe and Williams lake areas of British Columbia. After 3 to 4 days in deaerated water, almost no seed germinated. After 12 days seed viability was lost completely . Along the Loup Rivers of central Nebraska, yellow salsify occupied sites where the water table was 0 to 4 inches (10 cm) deep and sites with a water table over 40 inches (101 cm) deep .
Although yellow salsify is often found on open, disturbed sites, it is also found in relatively undisturbed sites and on sites with moderate canopy cover. Long-distance seed dispersal from more disturbed to less disturbed sites may play a role in yellow salsify's persistence.
Shading: While often most abundant in open sites, yellow salsify is somewhat shade tolerant and occurs in woodlands and forests [77,148]. In Theodore Roosevelt National Park, yellow salsify was most frequent in grasslands with little or no shrub or tree cover but occurred on some transects in all 11 vegetation types, including those dominated by sagebrush (Artemisia spp.), rubber rabbitbrush (Ericameria nauseousa subsp. nauseousa var. nauseousa), Rocky Mountain juniper (Juniperus scopulorum), and eastern cottonwood (Populus deltoides) . At Point of the Mountain, near Salt Lake City, Utah, yellow salsify seedlings were observed under the canopy of 9-year-old big sagebrush (A. tridentata) .
In a ponderosa pine/common snowberry (Pinus ponderosa/Symphoricarpos albus) community type in the foothills of eastern Oregon's Wallowa Mountains, trenching to reduce root competition increased yellow salsify density whereas thinning reduced yellow salsify density. Thinning treatments reduced tree density by about half. Yellow salsify increased significantly on trenched plots (P<0.05) .
|Yellow salsify density (number of plants/m²) one year after treaments |
|Control||Thinned only||Trenched only||Thinned and trenched|
Disturbances: Disturbed sites are common yellow salsify habitats, but persistence on disturbed sites is indefinite, and long-distance seed dispersal from disturbed sites into relatively open, undisturbed sites is common.
Yellow salsify is common on severely disturbed sites. In north-central New Mexico, yellow salsify made up only a trace of vegetative cover in pastures, but cover was 4% along roadsides . In Utah, yellow salsify is a disturbance indicator on rangelands . In southwestern Montana mining towns abandoned 45 to 77 years earlier, yellow salsify occurred on severely disturbed old roads and moderately disturbed areas near abandoned buildings. It did not occur in relatively undisturbed sites outside of the towns . In Billings County, North Dakota, yellow salsify occurred in 3 of 4 surveyed prairie dog towns. Towns are continually disturbed by prairie dog digging and burrowing, and by prairie dog and livestock grazing .
Relatively undisturbed sites, however, are also potential yellow salsify habitat. Yellow salsify occurred on both recently disturbed and relatively undisturbed portions of big sagebrush and antelope bitterbrush shrublands on the Columbia River Plain of Washington. Researchers were unsure if yellow salsify would persist on undisturbed sites without seed input from disturbed sites . In the Upper South Platte Watershed of central Colorado, yellow salsify occurred in both disturbed and relatively undisturbed ponderosa pine/Douglas-fir (Pseudotsuga menziesii) forests. Yellow salsify occurred on 3 of 30 plots within the Turkey Creek site that had been logged, grazed, burned, and used for recreation. On the relatively undisturbed Cheesman Lake plots, yellow salsify occurred on 9 of 30 plots . On the North Rim of Grand Canyon National Park, yellow salsify was 1 of the 3 nonnative species noted in remote, open, old-growth ponderosa pine stands, although the area was closed to grazing and protected from logging since the mid-1930s .
Grazing: Yellow salsify is often considered an indicator or invader of heavily grazed sites in the West [73,95,105]. However, in several studies, yellow salsify was either absent or less abundant on grazed than ungrazed sites. Grazing pattern may affect changes in yellow salsify abundance. For more on the use of yellow salsify by livestock and wildlife, see Importance to Wildlife and Livestock.
In mixed prairie vegetation in southeastern Alberta, yellow salsify cover was greatest on sites protected from large animal livestock grazing. On Chernozemic soils, yellow salsify cover was 0.2% on grazed and 1.2% on protected sites. On sites with Solonetzic soils, yellow salsify was absent from grazed sites and had 0.4% cover on protected sites. Litter biomass was greater on ungrazed than grazed sites but significantly greater (P<0.05) only on Chernozemic soils. Increased litter may have favored yellow salsify establishment on protected sites . Yellow salsify was absent from Letterman's needlegrass (Achnatherum lettermanii)-Kentucky bluegrass grasslands southeast of Cedar City, Utah, subjected to long-term (over 90 years) domestic sheep grazing. Aboveground biomass of yellow salsify was 7 kg/ha on late-seral grasslands opposite the fence of the sheep-grazed area . In semiarid western wheatgrass-bottlebrush squirreltail (Pascopyrum smithii-Elymus elymoides) grasslands of north-central Arizona, yellow salsify cover increased from 0% to 2% after 8 years of short-duration, high-impact cattle grazing .
Old field succession: Yellow salsify is typical in abandoned fields and pastures. Rarely is yellow salsify present and/or abundant in the first fallow year. In the early secondary succession of old fields, yellow salsify abundance commonly increases with increasing old field age. Yellow salsify has been observed in fields as old as 41 years. In southeastern Washington, yellow salsify was present in nearly all old fields sampled 1 to 52 years since abandonment. Cover and frequency were low (<1%) in the 1-year-old field. Cover and frequency of yellow salsify were 3% and 40%, respectively, 5 years after abandonment. In the 41-year-old field, cover was 2% and frequency 35%. In relatively undisturbed, presettlement habitats cover was 1% or less and frequency reached 12% . In eastern South Dakota's Lake Andes National Wildlife Refuge, corn and soybean fields were seeded to native grasses in 1971; the importance of yellow salsify increased in each successive year from 1973 to 1975 . Yellow salsify was abundant on old fields that averaged 26.7 years old in the Cedar Creek Natural History Area, southeastern Minnesota. The study evaluated 22 old fields 5 to 60 years old . In Ottertail County, Minnesota, yellow salsify occurred in a 30-year-old field. Abundance was not reported .
Secondary succession in forests and woodlands: Logged and/or burned forests and woodlands are likely habitat for yellow salsify, often within 3 years of the disturbance. In the Wallowa Mountains, researchers named Kentucky bluegrass-yellow salsify the early-seral community present 4 years after cutting and burning in a ponderosa pine-common snowberry habitat type . Yellow salsify was the most abundant nonnative 7 years after mixed-conifer forests were logged or logged and burned in California's Plumas National Forest. Yellow salsify did not occur in undisturbed, old-growth forests . In California's Tahoe National Forest, yellow salsify occurred on sites visited in 1989 that were burned by a wildfire in 1978, logged in 1979, slash burned in 1980, and planted to ponderosa pine in 1981 . Yellow salsify occurred on clearcuts in a mixed-conifer forest on the Challenge Experimental Forest in north-central California. Density was 33 plants/ha in the 3rd year after logging and 17 plants/ha 4 and 5 years after logging . In central Idaho, yellow salsify occurred in early-seral communities within the western redcedar/Oregon boxwood (Thuja plicata/ Paxistima myrsinites) habitat type. Yellow salsify frequency was 4% on a site burned 3 years earlier and 12% in more mature communities dominated by mature shrubs and young conifers. Yellow salsify did not occur in mid-seral to near-climax communities . Yellow salsify density increased dramatically in each of the 3 successive posttreatment years after anchor chaining in Colorado pinyon-Utah juniper (Pinus edulis-Juniperus osteosperma) woodlands near Ephraim, Utah. Chaining reduced the density of Utah juniper from 2,230 trees/ha to 186 trees/ha and Colorado pinyon trees from 620 trees/ha to 62 trees/ha .
Yellow salsify may be reproductive from April to September throughout its range. Based on 10 years of observations made in Swift Current, Saskatchewan, yellow salsify produced the earliest flowers on 26 May and the latest flowers on 27 September. The number of flowering days averaged 95 . The average number of flowering days was much lower, 23 days, after 6 years of observations near Woodworth, North Dakota . In north-central Arizona, yellow salsify reproductive development was delayed by about 3 weeks at cool, high-elevation sites .
|Timing of yellow salsify reproduction by state or region|
|State or region||Flowering period, unless otherwise noted|
seeds July-October 
|New Mexico||June-September |
|North Dakota||late May-early June |
|Utah, Uinta Basin||May-September |
|West Virginia||May-July |
|Blue Ridge Province||April-July |
|Great Plains||May-July |
|Northeastern United States and adjacent Canada||May-July |
Fire regimes: The prevailing fire regime in which yellow salsify evolved is not described in the available literature. Fire regimes in North American yellow salsify habitats are difficult to characterize, since it is possible in nearly any vegetation type. Because yellow salsify is a rapidly reproducing, early-seral species, it is unlikely that frequent fire would eliminate it. Elimination of the seed source is the only way yellow salsify could be lost from a community, and any disturbance by animals or extreme weather events has the potential of providing conditions for yellow salsify establishment, and with successful establishment a potential seed source. It is not likely that fire is necessary for the maintenance of yellow salsify habitats. Likely both short and long fire-return intervals would be tolerated.
Yellow salsify fuel characteristics were not described in the reviewed literature. However, dense populations are extremely rare, suggesting that yellow salsify has little effect on fuels or fire regimes where it occurs. Find fire regime information for the plant communities in which this species may occur by entering the species name in the FEIS home page under "Find Fire Regimes".
POSTFIRE REGENERATION STRATEGY :
Initial off-site colonizer (off site, initial community)
Secondary colonizer (on- or off-site seed sources)
DISCUSSION AND QUALIFICATION OF FIRE EFFECT:
No additional information is available on this topic.
PLANT RESPONSE TO FIRE:
Yellow salsify is primarily an off-site colonizer of burned sites. Yellow salsify's seed bank is short lived, but newly deposited seed could survive a fire producing minimal surface or soil heating. When soil samples taken from a needle-and-thread–blue grama community in the Greater Yellowstone Ecosystem were heated at 120 °F (50 °C) for 1 hour, 13 yellow salsify seedlings/m² emerged .
DISCUSSION AND QUALIFICATION OF PLANT RESPONSE:
Many fire studies report yellow salsify in both unburned and burned plots. Often yellow salsify was present in the first postfire years, and it persisted with low abundance on older, 8- to 30-year-old, burned sites. Large and/or long-lived changes in yellow salsify abundance due to fire were extremely rare. Increases or decreases in yellow salsify cover on burned sites rarely exceeded 1%, and frequency differences were typically less than 12%. There was no apparent pattern in yellow salsify's fire response by vegetation type, fire season, and/or fire severity. The table below is a summary of fire studies that include information on yellow salsify. Information is sorted by increasing time since fire within grassland, shrubland, and forested vegetation types.
|Summary of yellow salsify's response to fire in grasslands, shrublands, and forests|
|Vegetation type, study location||Fire date||Fire severity¹||Time since fire||Yellow salsify response²||Notes³|
|big bluestem-tall wheatgrass (Andropogon gerardii var. gerardii-Thinopyrum ponticum), ND||14 May||nd||1 mo.-1.3 years||-||1-3 months after fire, cover slightly greater on B than UB; absent from B sites in 1st postfire year |
|little bluestem (Schizachyrium scoparium)-tall wheatgrass, ND||13 June||nd||2 mo.-1.2 years||-||2 months after fire, cover on B slightly greater than prefire; cover lower on B in 1st postfire season |
|rough fescue, MT||28 June||"hot"||~ 4 mo.-1 year||+||Largest cover difference between B and UB was 0.2% in summer of 1st postfire year [5,89]|
|mountain rough fescue-Parry's oatgrass (F. campestris-Danthonia parryi), Alberta||14 December||"extremely hot"||1-2 years||--||Cover 0.1-0.2% on burned and 1.1% on unburned in 2nd postfire year; B and UB cover not different in 1st postfire year |
|Kentucky bluegrass, ND||May (2 fires)||nd||2 years||--||Cover significantly (P<0.05) lower on B than UB; postfire measurements taken 2 years after 2 consecutive May fires|
|bluebunch wheatgrass-Sandberg bluegrass, ID||August||low||2-3 years||-||Cover decreased from prefire on B and increased on UB |
|bluebunch wheatgrass-Sandberg bluegrass, OR||summer||moderate||1-5 years||0||Cover lower than prefire in 1st postfire year and equal in 5th postfire year |
|bluebunch wheatgrass-Sandberg bluegrass, OR||summer||high||1-5 years||++||Cover equal to prefire in 1st postfire year and 1% greater in 5th postfire year |
|Idaho fescue-prairie Junegrass (Koeleria macrantha), OR||summer||low||1-5 years||++||Prefire cover 0%, cover 1% in 1st and 5th postfire years |
|Idaho fescue-prairie Junegrass, OR||summer||moderate||1-5 years||--||Prefire and 1st postfire year cover 3%, cover 1% in 5th postfire year |
|Idaho fescue-bluebunch wheatgrass-arrowleaf balsamroot (Balsamorhiza sagittata), OR||summer||low||1-5 years||0||Prefire and 5th postfire year cover equal |
|Idaho fescue-bluebunch wheatgrass-arrowleaf balsamroot, OR||summer||moderate||1-5 years||++||0% cover in prefire and 1st postfire years; cover 1% in 5th postfire year |
|Idaho fescue-bluebunch wheatgrass-arrowleaf balsamroot, OR||summer||high||1-5 years||0||Cover 1% in prefire and 1st and 5th postfire years |
|bluebunch wheatgrass-Sandberg bluegrass, WA||July||nd||2-12 years||--||Cover and frequency increased more over time on UB; in nearly all postfire years cover and frequency lower on B than UB |
|big sagebrush/bluebunch wheatgrass, BC||26 June||nd||14 months||++||Absent from UB, frequency 6.7% on B |
|basin big sagebrush (Artemisia tridentata subsp. tridentata)/Idaho fescue-bluebunch wheatgrass, OR4||24 May||Reaction intensity: 792 kJ/m²/s; 84% consumption||1 year||--||Prefire frequency 15%, 1st postfire year frequency 9% [64,131]|
|basin big sagebrush/Idaho fescue-bluebunch wheatgrass, OR4||25 September||Reaction intensity: 2,626 kJ/m²/s; 92% consumption||1-2 years||--||3% frequency increase from prefire in 1st postfire year; 6% frequency decrease from prefire in 2nd postfire year [64,131]|
|big sagebrush/bluebunch wheatgrass, WA||1 October||nd||1-2 years||+||Frequency 0.5% greater than prefire in 1st and 2nd postfire years |
|rubber rabbitbrush/cheatgrass (Bromus tectorum), WA||July||nd||1-3 years||0||UB cover and frequency almost half that of B in 1st postfire year; B and UB cover and frequency nearly equal in 3rd postfire year |
|Wyoming big sagebrush (A. t. subsp. wyomingensis), cheatgrass, and pinyon (Pinus spp.)-Utah juniper, UT||July-August||nd||1-3 years||++||UB frequency nearly half that of B in 2nd and 3rd postfire years [112,113,114]|
|mountain big sagebrush (A. t. subsp. vaseyana)/Idaho fescue, OR||summer||moderate||1-5 years||0||Absent before fire, cover 1% in 1st postfire year and 0% in 5th postfire year |
|common snowberry-rose (Rosa spp.), OR||summer||moderate||1-5 years||0||Absent before fire, cover 2% in 1st postfire year in exclosures; cover 0-1% in 5th postfire year |
|smooth sumac (Rhus glabra)/bluebunch wheatgrass, OR||summer||moderate||1-5 years||++||Absent before fire, cover 1% in 1st and 5th postfire years |
|Gambel oak (Quercus gambelii), UT||unknown||nd||8-30 years||++||Frequency 0.9% on UB and 2.5% on B; most sites burned 8 years earlier |
|Douglas-fir, BC||July-August||low and high||1 year||+||Frequency 0 on UB, 2% on low- and high-severity B |
|ponderosa pine and adjacent grasslands, ID||10 August||nd||1-3 years||--||Frequency 3% and cover 1% greater on B than UB in 1st postfire year; frequency 3% and cover 1% lower on B than UB in 3rd postfire year |
|ponderosa pine, AZ||June-July||moderate and severe||2 years||0||Cover less than 0.5% on UB, moderate B, and severe B |
|ponderosa pine/Douglas-fir, MT||May-June||mixed||2 years||0||Cover unchanged on B, increased on thinned, and increased on thinned and B; described further in Research Project Summary |
|whitebark pine-subalpine fir (Pinus albicaulis-Abies lasiocarpa), MT||late June||low||2-3 years||unknown||Appeared on B; no UB or prefire comparison |
|ponderosa pine, AZ||June-July||low and high||2-3 years||unknown||Present on low- and high-severity B sites; abundance not reported, no UB or prefire comparison |
|ponderosa pine, AZ||early May||moderate and high||3 years||+||Present on moderate-severity B, absent from UB or high-severity B; sites logged 2 year before fire |
|western redcedar-western hemlock (Tsuga heterophylla), ID||August-September||high||1-10 years||0||Present on 1 of 18 B sites in 8th postfire year only |
|1Fire severity not directly described.
2Differences between burned and unburned or prefire condition. 0: no change, -: decrease <1% cover or <5% frequency, --: decrease ≥1% cover or ≥5% frequency, +: increase <1% cover or <5% frequency, ++: increase ≥1% cover or ≥5% frequency.
3B: burned, UB: unburned.
4See the Research Project Summary of this study for more information on fire effects on yellow salsify and 60 additional forb, grass, and woody plant species.
Lyon's Research Paper (Lyon 1971) also provides information on prescribed fire use and postfire response of plant species including yellow salsify.FIRE MANAGEMENT CONSIDERATIONS:
Grazing on burned sites with yellow salsify is likely to occur. In the foothills of Oregon's Wallowa Mountains, yellow salsify made up 25% of mule deer and elk diets from March to July. Yellow salsify was predominant in an area clearcut and burned 4 years prior to the study . In the Sun River area of west-central Montana, yellow salsify was important in elk, mule deer, and bighorn sheep winter diets. Yellow salsify was consumed most in 40- to 50-year-old burn sites dominated by snowberry (Symphoricarpos spp.) and bluebunch wheatgrass . Yellow salsify was utilized extensively by mule deer and domestic sheep on a very disturbed site in the Tahoe National Forest that was burned in a 1978 wildfire, logged in 1979, slash burned in 1980, and planted to ponderosa pine in 1981. By 1989, yellow salsify was nearly restricted to fenced areas .
Native ungulates: Although rarely abundant, yellow salsify is often found in elk, deer, bighorn sheep, pronghorn, and wild horse diets. Yellow salsify received consistent low levels of use by elk and mule deer in Montana's Missouri River Breaks, although its cover was less than 2% in all vegetation types studied . In the Sun River area of west-central Montana, yellow salsify was important in elk, mule deer, and bighorn sheep winter diets. It was consumed most in 40- to 50-year-old burned sites dominated by snowberry and bluebunch wheatgrass . Yellow salsify was utilized extensively by mule deer on a very disturbed site in the Tahoe National Forest. The site was burned by a wildfire in 1978, logged in 1979, slash burned in 1980, and planted to ponderosa pine in 1981. By 1989, yellow salsify was nearly restricted to fenced areas . On low-elevation winter range in north-central New Mexico, yellow salsify made up only a trace of the available forage but made up 9% of elk, 16% of mule deer, 17% of pronghorn, and 6% of wild horse diets . In the same area, pronghorn diets contained significantly (P<0.05) more yellow salsify (16% by weight) in a year when precipitation was 49% of normal than in a year when precipitation was 197% of normal (4% by weight) .
Elk: Yellow salsify made up 25% of elk diets from March to July in the foothills of Oregon's Wallowa Mountains. From mid-May to June, yellow salsify was 1 of the 2 most important forage species. Yellow salsify was dominant on the site clearcut and burned 4 years prior to the study . In June in Montana's Sapphire Mountains, yellow salsify had an elk preference index of 38. An index value of 1 or more indicated preference . On the Blacktail Plateau in northern Yellowstone National Park, yellow salsify was found significantly more often (P<0.05) on protected than on grazed sites; however, it was not eliminated from sites where elk density averaged 15 individuals/km² .
Deer: Studies from Oregon to Minnesota report yellow salsify in deer diets. Yellow salsify made up 25% of mule deer diets from March to July in the foothills of the Wallowa Mountains . In the Bridger Mountains of southwestern Montana, yellow salsify averaged 12% of the volume of 6 mule deer rumen samples . From 6 mule deer rumens collected in the summer from the Snowy Mountains of central Montana, yellow salsify made up 17% of rumen contents. In 3 fall-collected mule deer rumens, composition was 33% yellow salsify. White-tailed deer rumens collected in the same seasons contained almost no yellow salsify . In the Bear Paw Mountains of north-central Montana, yellow salsify was 41% of the total volume of mule deer summer diets. Yellow salsify made up only a trace of the volume of fall and winter diets . Yellow salsify was the most heavily used spring forb by white-tailed deer in the Missouri River bottomlands of north-central Montana. Yellow salsify volume averaged 15% in 13 spring-collected rumen samples . In an old field in Minnesota's Cedar Creek Natural History Area, white-tailed deer often consumed yellow salsify flowers .
Pronghorn: Pronghorn diets often include yellow salsify in the summer. In south-central Alberta, the volume of yellow salsify averaged 9% in summer pronghorn diets. In other seasons, yellow salsify volume was less than 1% . The volume of yellow salsify reached a maximum of 18% in pronghorn rumens collected from central Montana in August . In Petroleum County, Montana, the maximum volume of yellow salsify was 21.5% in summer-collected rumens . Yellow salsify was one of the most important pronghorn forages in 1 of the 2 years of observations made in South Dakota's Wind Cave National Park. Pronghorn consumed flower buds; by late summer, some plants were missing up to 6 flower stalks. Yellow salsify cover was less than 10.5% in the area .
Other mammals: Small and large mammals may feed on yellow salsify. Yellow salsify made up a minor component of grizzly bear scat collected in the Greater Yellowstone ecosystem . In laboratory feeding trials, plains pocket gophers trapped from east-central Minnesota's Cedar Creek Natural History Area consumed large quantities of yellow salsify . In a 10-year-old field in southwestern Michigan, between 3.1% and 8.4% of seeds were removed/dish/day by primarily deer mice. Differences in vegetation cover resulted in different amounts of seed removal .
Birds: Yellow salsify is important in the diets of juvenile and adult sharp-tailed grouse, sage-grouse, and dusky grouse. In northeastern Montana, the occurrence of yellow salsify was as high as 9% in the crops of juvenile and adult sharp-tailed grouse collected in September . In the summer on the Valentine National Wildlife Refuge in north-central Nebraska, the occurrence of goatsbeard averaged 13% in young and 34.1% in adult sharp-tailed grouse diets . Near Savery, Wyoming, yellow salsify occurred in all potential sage-grouse and sharp-tailed grouse habitats surveyed, but was more abundant in habitats selected by sage-grouse broods .
In Idaho and Montana, yellow salsify is an important juvenile sage-grouse food. In southeastern Idaho, yellow salsify made up the greatest volume (27%) and frequency (56%) in 6-week-old sage-grouse diets. Flower buds were preferred over stems and leaves . In the Medicine Lodge Area of Clark County, Idaho, the frequency of yellow salsify in the diets of sage-grouse chicks was 23% . Yellow salsify flower buds were the most preferred food of juvenile sage-grouse in central Montana. Yellow salsify made up a maximum average frequency and volume of 83% and 30%, respectively, in the crops of chicks 5 to 8 weeks old. In the rest of the juvenile age classes, the average yellow salsify frequencies were 41% to 60%. Yellow salsify frequency was 60% in the crops of adult sage-grouse killed in August . In another sage-grouse study in central Montana, the frequency of yellow salsify was 39% to 71%, and the volume was 20% to 25% in June to August sage-grouse diets. Spring and fall diets had much lower amounts of yellow salsify .
In Wallowa County, Oregon, yellow salsify was frequent in the fall diets of dusky grouse. Dusky grouse fed primarily on seed heads, and of the 145 crops analyzed, yellow salsify frequency averaged 41%. Yellow salsify was more frequent in mature and immature female crops than in mature and immature male crops .
Livestock: Cattle and domestic sheep will consume yellow salsify. In the Missouri River Breaks of Montana, yellow salsify received consistent, low-level use by cattle, although its cover was less than 2% in all vegetation types studied . In prairie and sagebrush habitats of north-central Montana, yellow salsify was a common forb in summer cattle diets . Yellow salsify was utilized extensively by domestic sheep on a site in the Tahoe National Forest that was highly disturbed. Within 8 years of the last disturbance, yellow salsify was nearly restricted to fenced areas . In north-central New Mexico, yellow salsify was more prevalent in cattle and domestic sheep diets during a drought year than an above-average precipitation year. Cattle diets were 12% yellow salsify in the drought year and 2% in the wet year. Domestic sheep diets were 7% yellow salsify in the drought year and only a trace in the wet year. Yellow salsify was rare in pastures but averaged 4% cover along roadsides .
Yellow salsify is edible and has been used to treat dog or coyote bites, boils, sore throats, and internal injuries of horses. Young yellow salsify leaves, stems, and roots are edible. Natives of British Columbia chewed the coagulated milk from yellow salsify stems like gum [7,36].
IMPACTS AND CONTROL:
Impacts: Yellow salsify is rarely abundant in any vegetation type. While yellow salsify may be persistent in open grassland and shrubland habitats, it rarely occupies much cover. Impacts on native vegetation and/or ecosystem processes were not noted in the available literature. In a Montana flora, yellow salsify was referred to as a "harmless" introduced species .
In many cases, yellow salsify is restricted to disturbed sites. In a survey of roadsides and disturbed sites in Yellowstone National Park and the Gallatin National Forest, yellow salsify occurred on roadsides and in clearcuts but abundance decreased from disturbed sites to the interior lodgepole pine (Pinus contorta)/antelope bitterbrush forests . In Glacier National Park, yellow salsify occurred on roadsides but not at distances 7 feet (2 m) into rough fescue-Idaho fescue grasslands . However, yellow salsify was 1 of 3 nonnative species in remote, open, old-growth ponderosa pine stands on the North Rim of Grand Canyon National Park that were protected from logging and grazing since the mid-1930s . Large yellow salsify populations are reported from British Columbia's southern Kootenay, Thompson-Nicola, and Okanagan regions .
Control: Limiting disturbances may be the most successful and most economical method of yellow salsify control. Some suggest that yellow salsify is not "aggressive" and that "control is seldom necessary" . In any control or management plans, yellow salsify's importance to wildlife should be considered. Potential control methods are discussed below.
Prevention: Studies and observations suggest that yellow salsify's survival, growth, and reproduction may be reduced by the presence of neighboring vegetation. After 10 years of observations in Swift Current, Saskatchewan, researchers noted that yellow salsify spread in "overgrazed" sites with "weakened" grasses . In a wind tunnel experiment, the number of yellow salsify seeds dispersing beyond neighboring vegetation decreased significantly (P<0.01) with the increasing height of neighboring vegetation . In another experiment, the presence of neighboring vegetation affected yellow salsify survival, growth, and reproduction moreso than disturbances by plains pocket gopher activities. Survival, growth, and reproduction were all significantly greater (P<0.05) when yellow salsify grew without other vegetation .
Integrated management: Upadhyaya and others suggest that herbicides and grazing can be used together to control yellow salsify .
Physical/mechanical: Yellow salsify is not a likely problem in cultivated fields but could persist in no-till systems .
Fire: See Fire Management Considerations.
Biological: Livestock and wildlife utilize yellow salsify, sometimes extensively. Flower and/or seed heads are consumed by sage-grouse , dusky grouse , pronghorn , and white-tailed deer . Native and nonnative herbivores may have played a role in limiting yellow salsify's abundance. However, the effects of grazing on yellow salsify are inconsistent. While herbivores likely eliminated portions of the season's seed, they also create disturbances and openings in canopy cover and may aid in seed dispersal. Grazing animal, intensity, and timing may all affect the usefulness of grazing to reduce yellow salsify abundance. In simulated grazing trials, 3 years of intense, early-season grazing decreased yellow salsify density by 25% to 50% (Blumenauer, personal communication, cited in ),.
Chemical: Herbicide effectiveness on yellow salsify is discussed in these references: [99,148].
Cultural: See Prevention. No additional information is available on this topic.
1. Allard, H. A. 1942. Tragopogon dubius; its response to length of day. Ecology. 23(1): 53-58. 
2. Allen, Eugene O. 1968. Range use, foods, condition, and productivity of white-tailed deer in Montana. The Journal of Wildlife Management. 32(1): 130-141. 
3. Alvarez, Helen; Ludwig, John A.; Harper, K. T. 1974. Factors influencing plant colonization of mine dumps at Park City, Utah. The American Midland Naturalist. 92(1): 1-11. 
4. Andersen, Mark C. 1993. Diaspore morphology and seed dispersal in several wind-dispersed Asteraceae. American Journal of Botany. 80(5): 487-492. 
5. Antos, Joseph A.; McCune, Bruce; Bara, Cliff. 1983. The effect of fire on an ungrazed western Montana grassland. The American Midland Naturalist. 110(2): 354-364. 
6. Ash, Maria; Lasko, Richard J. 1990. Postfire vegetative response in a whitebark pine community, Bob Marshall Wilderness, Montana. In: Schmidt, Wyman C.; McDonald, Kathy J., comps. Proceedings--symposium on whitebark pine ecosystems: ecology and management of a high-mountain resource; 1989 March 29-31; Bozeman, MT. Gen. Tech. Rep. INT-270. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 360-361. 
7. Bare, Janet E. 1979. Wildflowers and weeds of Kansas. Lawrence, KS: The Regents Press of Kansas. 509 p. 
8. Beaulieu, Jean Thomas. 1975. Effects of fire on understory plant populations in a northern Arizona ponderosa pine forest. Flagstaff, AZ: Northern Arizona University. 38 p. Thesis. 
9. Behrend, Andrew F.; Tester, John R. 1988. Feeding ecology of the plains pocket gopher in east central Minnesota. Prairie Naturalist. 20(2): 99-107. 
10. Blankespoor, Gilbert W. 1980. Prairie restoration: effects on nongame birds. The Journal of Wildlife Management. 44(3): 667-672. 
11. Blinn, Dean W.; Habeck, James R. 1967. An analysis of morainal vegetation in the upper Blackfoot Valley, Montana. Northwest Science. 41(3): 126-140. 
12. Booth, W. E.; Wright, J. C. 1962. [Revised]. Flora of Montana: Part II--Dicotyledons. Bozeman, MT: Montana State College, Department of Botany and Bacteriology. 280 p. 
13. Bork, Edward W.; Adams, Barry W.; Willms, Walter D. 2002. Resilience of foothills rough fescue, Festuca campestris, rangeland to wildfire. The Canadian Field-Naturalist. 116(1): 51-59. 
14. Bowns, James E.; Bagley, Calvin F. 1986. Vegetation responses to long-term sheep grazing on mountain ranges. Journal of Range Management. 39(5): 431-434. 
15. Brandt, C. A.; Rickard, W. H. 1994. Alien taxa in the North American shrub-steppe four decades after cessation of livestock grazing and cultivation agriculture. Biological Conservation. 68(2): 95-105. 
16. Bromley, Peter T. 1977. Aspects of the behavioural ecology and sociobiology of the pronghorn (Antilocapra americana). Calgary, AB: University of Calgary. 370 p. Dissertation. 
17. Brooks, Matthew L.; Esque, Todd C. 2002. Alien plants and fire in desert tortoise (Gopherus agassizii) habitat of the Mojave and Colorado deserts. Chelonian Conservation Biology. 4(2): 330-340. 
18. Budd, A. C.; Campbell, J. B. 1959. Flowering sequence of a local flora. Journal of Range Management. 12: 127-132. 
19. Callow, J. Michael; Kantrud, Harold A.; Higgins, Kenneth F. 1992. First flowering dates and flowering periods of prairie plants at Woodworth, North Dakota. Prairie Naturalist. 24(2): 57-64. 
20. Chepil, W. S. 1946. Germination of seeds. I. Longevity, periodicity of germination, and vitality of seeds in cultivated soil. Scientific Agriculture. 26: 307-346. 
21. Chong, Geneva W.; Otsuki, Yuka; Stohlgren, Thomas J.; Guenther, Debra; Evangelista, Paul; Villa, Cynthia; Waters, Alycia. 2006. Evaluating plant invasions from both habitat and species perspectives. Western North American Naturalist. 66(1): 92-105. 
22. Clark, David Lee. 1991. The effect of fire on Yellowstone ecosystem seed banks. Bozeman, MT: Montana State University. 115 p. Thesis. 
23. Clary, Warren P.; Kruse, William H. 1979. Phenology and rate of height growth of some forbs in the southwestern ponderosa pine type. Res. Note RM-376. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 8 p. 
24. Clements, David R.; Krannitz, Pam G.; Gillespie, Shauna M. 2007. Seed bank responses to grazing history by invasive and native plant species in a semi-desert shrub-steppe environment. Northwest Science. 81(1): 37-49. 
25. Clements, David R.; Upadhyaya, Mahesh K.; Bos, Shelley J. 1999. The biology of Canadian weeds. 110. Tragopogon dubius Scop., Tagopogon pratensis L., and Tragopogon porrifolius L. Canadian Journal of Plant Science. 79(1): 153-163. 
26. Cole, G. F. 1956. The pronghorn antelope: Its range use and food habits in central Montana with special reference to alfalfa. Technical Bulletin 516. Bozeman, MT: Montana State College, Agricultural Experiment Station. 63 p. 
27. Comes, R. D.; Bruns, V. F.; Kelley, A. D. 1978. Longevity of certain weed and crop seeds in fresh water. Weed Science. 26(4): 336-344. 
28. Cook, Linda M.; Soltis, Pamela S. 1999. Mating systems of diploid and allotetraploid populations of Tragopogon (Asteraceae). I. Natural populations. Heredity. 82(3): 237-244. 
29. Crawford, John A.; Olson, Rich A.; West, Neil E.; Mosley, Jeffrey C.; Schroeder, Michael A.; Whitson, Tom D.; Miller, Richard F.; Gregg, Michael A.; Boyd, Chad S. 2004. Ecology and management of sage-grouse and sage-grouse habitat. Journal of Range Management. 57(1): 2-19. 
30. Crawford, Julie A.; Wahren, C.-H. A.; Kyle, S.; Moir, W. H. 2001. Responses of exotic plant species to fires in Pinus ponderosa forests in northern Arizona. Journal of Vegetation Science. 12(2): 261-268. 
31. Cronquist, Arthur; Holmgren, Arthur H.; Holmgren, Noel H.; Reveal, James L.; Holmgren, Patricia K. 1994. Intermountain flora: Vascular plants of the Intermountain West, U.S.A. Vol. 5: Asterales. New York: The New York Botanical Garden. 496 p. 
32. Daubenmire, Rexford. 1975. Plant succession on abandoned fields, and fire influences, in a steppe area in southeastern Washington. Northwest Science. 49(1): 36-48. 
33. Davies, Kirk W.; Sheley, Roger L. 2007. Influence of neighboring vegetation height on seed dispersal: implications for invasive plant management. Weed Science. 55(6): 626-630. 
34. Davis, James N.; Harper, Kimball T. 1990. Weedy annuals and establishment of seeded species on a chained juniper-pinyon woodland in central Utah. In: McArthur, E. Durant; Romney, Evan M.; Smith, Stanley D.; Tueller, Paul T., compilers. Proceedings--symposium on cheatgrass invasion, shrub die-off, and other aspects of shrub biology and management; 1989 April 5-7; Las Vegas, NV. Gen. Tech. Rep. INT-276. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 72-79. 
35. Diggs, George M., Jr.; Lipscomb, Barney L.; O'Kennon, Robert J. 1999. Illustrated flora of north-central Texas. Sida Botanical Miscellany, No. 16. Fort Worth, TX: Botanical Research Institute of Texas. 1626 p. 
36. Duke, James A. 1992. Handbook of edible weeds. Boca Raton, FL: CRC Press. 246 p. 
37. Dusek, Gary L. 1975. Range relations of mule deer and cattle in prairie habitat. Journal of Wildlife Management. 39(3): 605-616. 
38. Fahselt, Dianne; Ownbey, Marion; Borton, Marla. 1976. Seed fertility in Tragopogon hybrids (Compositae). American Journal of Botany. 63(8): 1109-1118. 
39. Flora of North America Association. 2008. Flora of North America: The flora, [Online]. Flora of North America Association (Producer). Available: http://www.fna.org/FNA. 
40. Forcella, Frank; Harvey, Stephen J. 1981. New and exotic weeds of Montana. II: Migration and distribution of 100 alien weeds in northwestern USA, 1881-1980. Cooperative Agreement No. 12-6-5-2383: Noxious and exotic weed survey of Montana. Helena, MT: Montana Department of Agriculture. 117 p. 
41. Fornwalt, Paula J.; Kaufmann, Merrill R.; Huckaby, Laurie S.; Stoker, Jason M.; Stohlgren, Thomas J. 2003. Non-native plant invasions in managed and protected ponderosa pine/Douglas-fir forests of the Colorado Front Range. Forest Ecology and Management. 177: 515-527. 
42. Gleason, Henry A.; Cronquist, Arthur. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. 2nd ed. New York: New York Botanical Garden. 910 p. 
43. Gleeson, Scott K.; Tilman, David. 1990. Allocation and the transient dynamics of succession on poor soils. Ecology. 71(3): 1144-1155. 
44. Goodrich, Sherel; Neese, Elizabeth. 1986. Uinta Basin flora. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Region, Ashley National Forest; Vernal, UT: U.S. Department of the Interior, Bureau of Land Management, Vernal District. 320 p. 
45. Goodrich, Sherel; Rooks, Dustin. 1999. Control of weeds at a pinyon-juniper site by seeding grasses. In: Monsen, Stephen B.; Stevens, Richard, compilers. Proceedings: ecology and management of pinyon-juniper communities within the Interior West: Sustaining and restoring a diverse ecosystem; 1997 September 15-18; Provo, UT. Proceedings RMRS-P-9. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station: 403-407. 
46. Gray, Gene Mack. 1967. An ecological study of sage grouse broods with reference to nesting, movements, food habits, and sagebrush strip spraying in the Medicine Lodge drainage, Clark County, Idaho. Moscow, ID: University of Idaho. 200 p. Thesis. 
47. Great Plains Flora Association. 1986. Flora of the Great Plains. Lawrence, KS: University Press of Kansas. 1392 p. 
48. Gross, Katherine L. 1981. Predictions of fate from rosette size in four "biennial" plant species: Verbascum thapsus, Oenothera biennis, Daucus carota, and Tragopogon dubius. Oecologia. 48(2): 209-213. 
49. Gross, Katherine L. 1984. Effects of seed size and growth form on seedling establishment of six monocarpic perennial plants. Journal of Ecology. 72(2): 369-387. 
50. Gross, Katherine L.; Werner, Patricia A. 1982. Colonizing abilities of "biennial" plant species in relation to ground cover: implications for their distributions in a successional sere. Ecology. 63(4): 921-931. 
51. Gross, Katherine Lynn. 1980. Ecological consequences of differences in life history charactereistics among four "biennial" plant species. East Lansing, MI: Michigan State University. 120 p. Dissertation. 
52. Gucker, Corey. 2004. Canyon grassland vegetation changes following the Maloney Creek wildfire. Moscow, ID: University of Idaho. 80 p. Thesis. 
53. Hann, Wendel; Havlina, Doug; Shlisky, Ayn; [and others]. 2005. Interagency fire regime condition class guidebook. Version 1.2, [Online]. In: Interagency fire regime condition class website. U.S. Department of Agriculture, Forest Service; U.S. Department of the Interior; The Nature Conservancy; Systems for Environmental Management (Producer). Variously paginated [+ appendices]. Available: http://www.frcc.gov/docs/184.108.40.206/Complete_Guidebook_V1.2.pdf [2007, May 23]. 
54. Harrington, H. D. 1964. Manual of the plants of Colorado. 2nd ed. Chicago, IL: The Swallow Press, Inc. 666 p. 
55. Hazelwood, Donna. 2001. Preliminary examination of species of an abandoned farm field in tallgrass mixed hardwood forest in Ottertail County, Minnesota. In: Bernstein, Neil P.; Ostrander, Laura J., eds. Proceedings of the 17th North American prairie conference: Seeds for the future;roots of the past:; 2000 July 16-20; Mason City, IA. Mason City, IA: North Iowa Community College: 42-47. 
56. Hickman, James C., ed. 1993. The Jepson manual: Higher plants of California. Berkeley, CA: University of California Press. 1400 p. 
57. Hitchcock, C. Leo; Cronquist, Arthur. 1973. Flora of the Pacific Northwest. Seattle, WA: University of Washington Press. 730 p. 
58. Johnson, A. H.; Strang, R. M. 1983. Burning in a bunchgrass/sagebrush community: the southern interior of B.C. and northwestern U.S. compared. Journal of Range Management. 36(5): 616-618. 
59. Johnson, Charles Grier, Jr. 1998. Vegetation response after wildfires in national forests of northeastern Oregon. R6-NR-ECOL-TP-06-98. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Region. 128 p. plus appendices. 
60. Johnson, James R.; Nichols, James T. 1970. Plants of South Dakota grasslands: A photographic study. Bull. 566. Brookings, SD: South Dakota State University, Agricultural Experiment Station. 163 p. 
61. Kamps, George Frank. 1969. Whitetail and mule deer relationships in the Snowy Mountains of central Montana. Bozeman, MT: Montana State University. 59 p. Thesis. 
62. Kartesz, John T. 1999. A synonymized checklist and atlas with biological attributes for the vascular flora of the United States, Canada, and Greenland. 1st ed. In: Kartesz, John T.; Meacham, Christopher A. Synthesis of the North American flora (Windows Version 1.0), [CD-ROM]. Chapel Hill, NC: North Carolina Botanical Garden (Producer). In cooperation with: The Nature Conservancy; U.S. Department of Agriculture, Natural Resources Conservation Service; U.S. Department of the Interior, Fish and Wildlife Service. 
63. Kartesz, John Thomas. 1988. A flora of Nevada. Reno, NV: University of Nevada. 1729 p. [In 2 volumes]. Dissertation. 
64. Kauffman, J. Boone; Sapsis, David B.; Till, Kenneth M. 1997. Ecological studies of fire in sagebrush/bunchgrass ecosystems of the John Day Fossil Beds National Monument, Oregon: implications for the use of prescribed burning to maintain natural ecosystems. Technical Report NPS/CCOSU/NRTR-97/01. Seattle, WA: U.S. Department of the Interior, National Park Service, Columbia Cascades System Support Office. 148 p. 
65. Kayler, Zachary E.; Fortini, Lucas B.; Battles, John J. 2005. Group selection edge effects on the vascular plant community of a Sierra Nevada old-growth forest. Madrono. 52(4): 262-266. 
66. Kearney, Thomas H.; Peebles, Robert H.; Howell, John Thomas; McClintock, Elizabeth. 1960. Arizona flora. 2nd ed. Berkeley, CA: University of California Press. 1085 p. 
67. Klebenow, Donald A.; Gray, Gene M. 1968. Food habits of juvenile sage grouse. Journal of Range Management. 21(2): 80-83. 
68. Klott, James H.; Lindzey, Frederick G. 1990. Brood habitats of sympatric sage grouse and Columbian sharp-tailed grouse in Wyoming. Journal of Wildlife Management. 54(1): 84-88. 
69. Knapp, Paul A. 1991. The response of semi-arid vegetation assemblages following the abandonment of mining towns in southwestern Montana. Journal of Arid Environments. 20: 205-222. 
70. Kobriger, Gerald D. 1965. Status, movements, habitats, and foods of prairie grouse on a sandhills refuge. The Journal of Wildlife Management. 29(4): 788-800. 
71. Kuenzi, Amanda M.; Fule, Peter Z.; Sieg, Carolyn Hull. 2008. Effects of fire severity and pre-fire stand treatment on plant community recovery after a large wildfire. Forest Ecology and Management. 255(3-4): 855-865. 
72. Kunzler, L. M.; Harper, K. T.; Kunzler, D. B. 1981. Compositional similarity within the oakbrush type in central and northern Utah. The Great Basin Naturalist. 41(1): 147-153. 
73. Lacey, John; Mosley, John. 2002. 250 plants for range contests in Montana. MONTGUIDE MT198402 AG 6/2002. Range E-2 (Misc.). Bozeman, MT: Montana State University, Extension Service. 4 p. 
74. Lackschewitz, Klaus. 1991. Vascular plants of west-central Montana--identification guidebook. Gen. Tech. Rep. INT-227. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 648 p. 
75. LANDFIRE Rapid Assessment. 2005. Reference condition modeling manual (Version 2.1), [Online]. In: LANDFIRE. Cooperative Agreement 04-CA-11132543-189. Boulder, CO: The Nature Conservancy; U.S. Department of Agriculture, Forest Service; U.S. Department of the Interior (Producers). 72 p. Available: http://www.landfire.gov/downloadfile.php?file=RA_Modeling_Manual_v2_1.pdf [2007, May 24]. 
76. LANDFIRE Rapid Assessment. 2007. Rapid assessment reference condition models, [Online]. In: LANDFIRE. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Lab; U.S. Geological Survey; The Nature Conservancy (Producers). Available: http://www.landfire.gov/models_EW.php [2008, April 18] 
77. Larson, Diane L.; Anderson, Patrick J.; Newton, Wesley. 2001. Alien plant invasion in mixed-grass prairie: effects of vegetation type and anthropogenic disturbance. Ecological Applications. 11(1): 128-141. 
78. Laughlin, Daniel C.; Bakker, Jonathan D.; Stoddard, Michael T.; Daniels, Mark L.; Springer, Judith D.; Gildar, Cara N.; Green, Aaron M.; Covington, W. Wallace. 2004. Toward reference conditions: wildfire effects on flora in an old-growth ponderosa pine forest. Forest Ecology and Management. 199: 137-152. 
79. Leck, Mary Allessio; Leck, Charles F. 2005. Vascular plants of a Delaware River tidal freshwater wetland and adjacent terrestrial areas: seed bank and vegetation comparisons of reference and constructed marshes and annotated species list. Journal of the Torrey Botanical Society. 132(2): 323-354. 
80. Link, Steven O.; Hill, Randal W. [In preparation]. Effect of prescribed fire on a shrub-steppe plant community infested with Bromus tectorum. International Journal of Wildland Fire. 
81. Loeser, Matthew R.; Sisk, Thomas D.; Crews, Timothy E. 2007. Impact of grazing intensity during drought in an Arizona grassland. Conservation Biology. 21(1): 87-97. 
82. Mackie, Richard J. 1970. Range ecology and relations of mule deer, elk, and cattle in the Missouri River Breaks, Montana. Wildlife Monographs No. 20. Washington, DC: The Wildlife Society. 79 p. 
83. Marcum, C. Les. 1979. Summer-fall food habits and forage preferences of a western Montana elk herd. In: Boyce, Mark S.; Hayden-Wing, Larry D., eds. North American elk: ecology, behavior and management. Laramie, WY: The University of Wyoming: 54-62. 
84. Martin, Robert C. 1990. Sage grouse responses to wildfire in spring and summer habitats. Moscow, ID: University of Idaho. 36 p. Thesis. 
85. Martin, William C.; Hutchins, Charles R. 1981. A flora of New Mexico. Volume 2. Germany: J. Cramer. 2589 p. 
86. Martinka, C. J. 1968. Habitat relationships of white-tailed deer and mule deer in northern Montana. The Journal of Wildlife Management. 32: 558-565. 
87. Mattson, David J.; Blanchard, Bonnie M.; Knight, Richard R. 1991. Food habits of Yellowstone grizzly bears, 1977-1987. Canadian Journal of Zoology. 69(6): 1619-1629. 
88. Maxwell, Christine D.; Zobel, Alicja; Woodfine, David. 1994. Somatic polymorphism in the achenes of Tragopogon dubius. Canadian Journal of Botany. 72: 1282-1288. 
89. McCune, Bruce. 1978. First-season fire effects on intact palouse prairie. Unpublished report on file with: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, MT. 12 p. 
90. McDonald, Philip M. 1999. Diversity, density, and development of early vegetation in a small clear-cut environment. Res. Pap. PSW-RP-239. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. 22 p. 
91. McDonald, Philip M.; Fiddler, Gary O. 1993. Vegetative trends in a young conifer plantation after 10 years of grazing by sheep. Res. Pap. PSW-RP-215. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. 9 p. 
92. McDonough, Walter T. 1969. Seedling growth of ten species from subalpine rangeland in Utah as affected by controlled diurnal temperature alterations. The American Midland Natrualist. 82(1): 276-279. 
93. McGinley, M. A.; Brigham, E. J. 1989. Fruit morphology and terminal velocity in Tragopogon dubius (L.). Functional Ecology. 3: 489-496. 
94. McGinley, Mark A. 1989. Within and among plant variation in seed mass and pappus size in Tragopogon dubius. Canadian Journal of Botany. 67: 1298-1304. 
95. Merigliano, Michael F. 1996. Ecology and management of the South Fork Snake River cottonwood forest. Tech. Bulletin 96-9. Boise, ID: U.S. Department ot the Interior, Bureau of Land Management, Idaho State Office. 79 p. 
96. Merrill, Evelyn H.; Mayland, Henry F.; Peek, James M. 1980. Effects of a fall wildfire on herbaceous vegetation on xeric sites in the Selway-Bitterroot Wilderness, Idaho. Journal of Range Management. 33(5): 363-367. 
97. Merritt, David M.; Wohl, Ellen E. 2006. Plant dispersal along rivers fragmented by dams. River Research and Applications. 22: 1-26. 
98. Metlen, Kerry L.; Dodson, Erich K.; Fiedler, Carl E. 2006. Research Project Summary--Vegetation response to restoration treatments in ponderosa pine/Douglas-fir forests. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis. 
99. Miller, Richard F.; Eddleman, Lee L. 2000. Spatial and temporal changes of sage grouse habitat in the sagebrush biome. Technical Bulletin 151. Corvallis, OR: Oregon State University, Agricultural Experiment Station. 35 p. 
100. Miller, Richard F.; Krueger, William C.; Vavra, Martin. 1981. Deer and elk use on foothill rangelands in northeastern Oregon. Journal of Range Management. 34(3): 201-204. 
101. Mitchell, George J.; Riegert, Paul W. 1994. Sharp-tailed grouse, Tympanuchus phasianellus, and grasshoppers: food is when you find it. The Canadian Field-Naturalist. 108(3): 288-291. 
102. Mitchell, George J.; Smoliak, Sylvester. 1971. Pronghorn antelope range characteristics and food habits in Alberta. The Journal of Wildlife Management. 35(2): 238-250. 
103. Mittelbach, Gary G.; Gross, Katherine L. 1984. Experimental studies of seed predation in old-fields. Oecologia. 65: 7-13. 
104. Mohlenbrock, Robert H. 1986. [Revised edition]. Guide to the vascular flora of Illinois. Carbondale, IL: Southern Illinois University Press. 507 p. 
105. Mueggler, W. F.; Stewart, W. L. 1980. Grassland and shrubland habitat types of western Montana. Gen. Tech. Rep. INT-66. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station. 154 p. 
106. Mulligan, Gerald A.; Findlay, Judy N. 1970. Reproductive systems and colonization in Canadian weeds. Canadian Journal of Botany. 48(2): 859-860. 
107. Munz, Philip A.; Keck, David D. 1973. A California flora and supplement. Berkeley, CA: University of California Press. 1905 p. 
108. Murphy, Stephen D.; Clements, David R.; Belaoussoff, Svenja; Kevan, Peter G.; Swanton, Clarence J. 2006. Promotion of weed species diversity and reduction of weed seedbanks with conservation tillage and crop rotation. Weed Science. 54(1): 69-77. 
109. Nagel, Harold G.; Rothenberger, Steven. 1999. Response of wetland plants to groundwater depth on the Middle Loup River, Nebraska. In: Springer, J. T., ed. The central Nebraska Loess Hills prairie: Proceedings of the 16th North American prairie conference; 1998 July 26-29; Kearney, NE. No. 16. Kearney, NE: University of Nebraska: 216-225. 
110. Novak, Stephen J.; Soltis, Douglas E.; Soltis, Pamela S. 1991. Ownbey's Tragopogons: 40 years later. American Journal of Botany. 78(11): 1586-1600. 
111. Olson, Wendell W. 1975. Effects of controlled burning on grassland within the Tewaukon National Wildlife Refuge. Fargo, ND: North Dakota University of Agriculture and Applied Science. 137 p. Thesis. 
112. Ott, Jeffrey E. 2001. Vegetation of chained and non-chained rangelands following wildfire and rehabilitation in west-central Utah. Provo, UT: Brigham Young University. 79 p. Thesis. 
113. Ott, Jeffrey E.; McArthur, E. Durant; Roundy, Bruce A. 2003. Vegetation of chained and non-chained seedings after wildfire in Utah. Journal of Range Management. 56(1): 81-91. 
114. Ott, Jeffrey E.; McArthur, E. Durant; Sanderson, Stewart C. 2001. Plant community dynamics of burned and unburned sagebrush and pinyon-juniper vegetation in west-central Utah. In: McArthur, E. Durant; Fairbanks, Daniel J., compilers. Shrubland ecosystem genetics and biodiversity: proceedings; 2000 June 13-15; Provo, UT. Proc. RMRS-P-21. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station: 177-191. 
115. Ownbey, Marion. 1950. Natural hybridization and amphiploidy in the genus Tragopogon. American Journal of Botany. 37(10): 487-499. 
116. Parker, Karl G. 1975. Some important Utah range plants. Extension Service Bulletin EC-383. Logan, UT: Utah State University. 174 p. 
117. Pauchard, Anibal; Alaback, Paul B. 2006. Edge type defines alien plant species invasions along Pinus contorta burned, highway and clearcut forest edges. Forest Ecology and Management. 223(1-3): 327-335. 
118. Pendleton, R. I.; Smith, B. N. 1983. Vesicular-arbuscular mycorrhizae of weedy and colonizer plant species at disturbed sites in Utah. Oecologia. 59: 296-301. 
119. Peterson, J. G. 1970. The food habits and summer distribution of juvenile sage grouse in central Montana. The Journal of Wildlife Management. 34(1): 147-155. 
120. Platt, William J. 1975. The colonization and formation of equilibrium plant species associations on badger disturbances in a tall-grass prairie. Ecological Monographs. 45: 285-305. 
121. Pojar, Jim; MacKinnon, Andy, eds. 1994. Plants of the Pacific Northwest coast: Washington, Oregon, British Columbia and Alaska. Redmond, WA: Lone Pine Publishing. 526 p. 
122. Qi, Meiqin; Upadhyaya, Mahesh K. 1993. Seed germination ecophysiology of meadow salsify (Tragopogon pratensis) and western salsify (T. dubius). Weed Science. 41(3): 362-368. 
123. Radford, Albert E.; Ahles, Harry E.; Bell, C. Ritchie. 1968. Manual of the vascular flora of the Carolinas. Chapel Hill, NC: The University of North Carolina Press. 1183 p. 
124. Raunkiaer, C. 1934. The life forms of plants and statistical plant geography. Oxford: Clarendon Press. 632 p. 
125. Reader, R. J. 1993. Control of seedling emergence by ground cover and seed predation in relation to seed size for some old-field species. Journal of Ecology. 81: 169-175. 
126. Reader, R. J. 1997. Potential effects of granivores on old field succession. Canadian Journal of Botany. 75(12): 2224-2227. 
127. Reichman, O. J. 1995. The influence of crowding and pocket gopher disturbance on growth and reproduction of a biennial, Tragopogon dubius. In: Hartnett, David C., ed. Proceedings of the 14th North American prairie conference: prairie biodiversity; 1994 July 12-16; Manhattan, KS. Manhattan, KS: Kansas State University. 
128. Reichman, O. J.; Smith, Stan C. 1991. Responses to simulated leaf and root herbivory by a biennial, Tragopogon dubius. Ecology. 72(1): 116-124. 
129. Riegel, Gregg M.; Miller, Richard F.; Krueger, William C. 1995. The effects of aboveground and belowground competition in a Pinus ponderosa forest. Forest Science. 41(4): 864-889. 
130. Roper, Laren Alden. 1970. Some aspects of the synecology of Cornus nuttallii in northern Idaho. Moscow, ID: University of Idaho. 81 p. Thesis. 
131. Sapsis, David B. 1990. Ecological effects of spring and fall prescribed burning on basin big sagebrush/Idaho fescue--bluebunch wheatgrass communities. Corvallis, OR: Oregon State University. 105 p. Thesis. 
132. Schallenberger, Allen Dee. 1966. Food habits, range use and interspecific relationships of bighorn sheep in the Sun River area, west-central Montana. Bozeman, MT: Montana State University. 44 p. Thesis. 
133. Seymour, Frank Conkling. 1982. The flora of New England. 2nd ed. Phytologia Memoirs 5. Plainfield, NJ: Harold N. Moldenke and Alma L. Moldenke. 611 p. 
134. Singer, F. J.; Hartner, M. K. 1996. Comparative effects of elk herbivory and the fires of 1988 on grasslands in northern Yellowstone National Park. In: Effects of grazing by wild ungulates in Yellowstone National Park. Technical Report NPS/NRYELL/NRTR/96-10. Washington, DC: U.S. Department of the Interior, National Park Service, Yellowstone National Park: 97-113. 
135. Stark, Kaeli E.; Arsenault, Andre; Bradfield, Gary E. 2006. Soil seed banks and plant community assembly following disturbance by fire and logging in interior Douglas-fir forests of south-central British Columbia. Canadian Journal of Botany. 84(10): 1548-1560. 
136. Stephenson, Thor E.; Holechek, Jerry L.; Kuykendall, Charles B. 1985. Diets of four wild ungulates on winter range in northcentral New Mexico. The Southwestern Naturalist. 30(3): 437-441. 
137. Stephenson, Thor E.; Holechek, Jerry L.; Kuykendall, Charles B. 1985. Drought effect on pronghorn and other ungulate diets. The Journal of Wildlife Management. 49(1): 146-151. 
138. Stevens, Lawrence E.; Ayers, Tina. 2002. The biodiversity and distribution of exotic vascular plants and animals in the Grand Canyon region. In: Tellman, Barbara, ed. Invasive exotic species in the Sonoran region. Arizona-Sonora Desert Museum Studies in Natural History. Tucson, AZ: The University of Arizona Press; The Arizona-Sonora Desert Museum: 241-265. 
139. Stevens, O. A. 1956. Flowering dates of weeds in North Dakota. North Dakota Agricultural Experiment Station Bimonthly Bulletin. 18(6): 209-213. 
140. Stevens, O. A. 1957. Weights of seeds and numbers per plant. Weeds. 5: 46-55. 
141. Stickney, Peter F. 1986. First decade plant succession following the Sundance Forest Fire, northern Idaho. Gen. Tech. Rep. INT-197. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 26 p. 
142. Stickney, Peter F. 1989. Seral origin of species comprising secondary plant succession in Northern Rocky Mountain forests. FEIS workshop: Postfire regeneration. Unpublished draft on file at: U.S. Department of Agriculture, Forest Service, Intermountain Research Station, Fire Sciences Laboratory, Missoula, MT. 10 p. 
143. Stockrahm, Donna M. Bruns; Olson, Theresa Ebbenga; Harper, Elizabeth K. 1993. Plant species in black-tailed prairie dog towns in Billings County, North Dakota. Prairie Naturalist. 25(2): 173-183. 
144. Strausbaugh, P. D.; Core, Earl L. 1977. Flora of West Virginia. 2nd ed. Morgantown, WV: Seneca Books, Inc. 1079 p. 
145. Stubbendieck, James; Coffin, Mitchell J.; Landholt, L. M. 2003. Weeds of the Great Plains. 3rd ed. Lincoln, NE: Nebraska Department of Agriculture, Bureau of Plant Industry. 605 p. In cooperation with: University of Nebraska, Lincoln. 
146. Tyser, Robin W.; Worley, Christopher A. 1992. Alien flora in grasslands adjacent to road and trail corridors in Glacier National Park, Montana (U.S.A.). Conservation Biology. 6(2): 253-262. 
147. U.S. Department of Agriculture, Natural Resources Conservation Service. 2008. PLANTS Database, [Online]. Available: http://plants.usda.gov/. 
148. Upadhyaya, M. K.; Qi, M. Q.; Furness, N. H.; Cranston, R. S. 1993. Meadow salsify and western salsify--two rangeland weeds of British Columbia. Rangelands. 15(4): 148-150. 
149. Upadhyaya, Mahesh K.; Furness, Nancy H. 1994. Influence of light intensity and water stress on leaf surface characteristics of Cynoglossum officinale, Centaurea spp., Tragopogon spp. Canadian Journal of Botany. 72: 1379-1386. 
150. Voss, Edward G. 1996. Michigan flora. Part III: Dicots (Pyrolaceae--Compositae). Bulletin 61: Cranbrook Institute of Science; University of Michigan Herbarium. Ann Arbor, MI: The Regents of the University of Michigan. 622 p. 
151. Wallestad, Richard; Peterson, Joel G.; Eng, Robert L. 1975. Foods of adult sage grouse in central Montana. Journal of Wildlife Management. 39(3): 628-630. 
152. Weber, William A. 1987. Colorado flora: western slope. Boulder, CO: Colorado Associated University Press. 530 p. 
153. Weber, William A.; Wittmann, Ronald C. 1996. Colorado flora: eastern slope. 2nd ed. Niwot, CO: University Press of Colorado. 524 p. 
154. Welch, Bruce L. 2005. Big sagebrush chemistry and water relations. In: Welch, Bruce L., ed. Big sagebrush: a sea fragmented into lakes, ponds, and puddles. Gen. Tech. Rep. RMRS-GTR-144. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station: 107-148. 
155. Welsh, Stanley L.; Atwood, N. Duane; Goodrich, Sherel; Higgins, Larry C., eds. 1987. A Utah flora. The Great Basin Naturalist Memoir No. 9. Provo, UT: Brigham Young University. 894 p. 
156. Wentland, Harold James. 1968. Summer range habits of the pronghorn antelope in central Montana with special reference to proposed sagebrush control study plots. Bozeman, MT: Montana State University. 65 p. Thesis. 
157. Wilkins, Bruce T. 1957. Range use, food habits, and agricultural relationships of the mule deer, Bridger Mountains, Montana. Journal of Wildlife Management. 21(2): 159-169. 
158. Willms, Walter D.; Dormaar, Johan F.; Adams, Barry W.; Douwes, Harriet E. 2002. Response of the mixed prairie to protection from grazing. Journal of Range Management. 55(3): 210-216. 
159. Wofford, B. Eugene. 1989. Guide to the vascular plants of the Blue Ridge. Athens, GA: The University of Georgia Press. 384 p. 
160. Yake, Steven; Brotherson, Jack D. 1979. Differentiation of serviceberry habitats in the Wasatch Mountains of Utah. Journal of Range Management. 32(5): 379-383; 1979.