Goodyera oblongifolia


Table of Contents


INTRODUCTORY


Photo 2001 Steven Thorsted

AUTHORSHIP AND CITATION:
Reeves, Sonja L. 2006. Goodyera oblongifolia. 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/ [].

FEIS ABBREVIATION:
GOOOBL

SYNONYMS:
Goodyera decipiens (Hook) F.T. Hubbard. [26]
Peramium decipiens Piper [3]

NRCS PLANT CODE [98]:
GOOB2

COMMON NAMES:
western rattlesnake plantain
rattlesnake plantain

TAXONOMY:
The scientific name of western rattlesnake plantain is Goodyera oblongifolia Raf. (Orchidaceae) [37,42,49,56,64,81,100]. Checkered rattlesnake plantain (G. tesselata) is a stable hybrid of western rattlesnake plantain and northern rattlesnake plantain (G. repens) [15,54,55]. When information specific to western rattlesnake plantain is not available, references will be made to the genus Goodyera.

LIFE FORM:
Forb

FEDERAL LEGAL STATUS:
No special status

OTHER STATUS:
Information on state-level protected status of plants in the United States is available at Plants Database.

DISTRIBUTION AND OCCURRENCE

SPECIES: Goodyera oblongifolia
GENERAL DISTRIBUTION:
Western rattlesnake plantain has a disjunct distribution. In the West, it occurs from extreme southeast Alaska east to western South Dakota and south to central California, southern Arizona, and southern New Mexico. Isolated populations occur in extreme southwest Saskatchewan and northwest Nebraska. In the Great Lakes region, it occurs from southern Ontario south to Wisconsin and Michigan. Isolated populations occur further east from southern Ontario east to New Brunswick and south to northern Vermont and northern Maine [37,49,50,52,56,81]. Flora of North America provides a distributional map of western rattlesnake plantain.

ECOSYSTEMS [39]:
FRES11 Spruce-fir
FRES20 Douglas-fir
FRES21 Ponderosa pine
FRES22 Western white pine
FRES23 Fir-spruce
FRES24 Hemlock-Sitka spruce
FRES25 Larch
FRES26 Lodgepole pine
FRES27 Redwood

STATES/PROVINCES: (key to state/province abbreviations)
UNITED STATES

AK AZ CA CO ID ME MI MT NE NM
OR SD UT VT WA WI WY

CANADA
AB BC NB NS ON PQ SK

MEXICO

BLM PHYSIOGRAPHIC REGIONS [20]:
1 Northern Pacific Border
2 Cascade Mountains
3 Southern Pacific Border
4 Sierra Mountains
5 Columbia Plateau
6 Upper Basin and Range
7 Lower Basin and Range
8 Northern Rocky Mountains
9 Middle Rocky Mountains
10 Wyoming Basin
11 Southern Rocky Mountains
12 Colorado Plateau
13 Rocky Mountain Piedmont
15 Black Hills Uplift
16 Upper Missouri Basin and Broken Lands

KUCHLER [63] PLANT ASSOCIATIONS:
K001 Spruce-cedar-hemlock forest
K002 Cedar-hemlock-Douglas-fir forest
K003 Silver fir-Douglas-fir forest
K004 Fir-hemlock forest
K005 Mixed conifer forest
K006 Redwood forest
K007 Red fir forest
K008 Lodgepole pine-subalpine forest
K011 Western ponderosa forest
K012 Douglas-fir forest
K013 Cedar-hemlock-pine forest
K014 Grand fir-Douglas-fir forest
K015 Western spruce-fir forest
K016 Eastern ponderosa forest
K017 Black Hills pine forest
K018 Pine-Douglas-fir forest
K019 Arizona pine forest
K020 Spruce-fir-Douglas-fir forest
K021 Southwestern spruce-fir forest
K029 California mixed evergreen forest
K093 Great Lakes spruce-fir forest

SAF COVER TYPES [33]:
5 Balsam fir
18 Paper birch
37 Northern white-cedar
107 White spruce
201 White spruce
202 White spruce-paper birch
205 Mountain hemlock
206 Engelmann spruce-subalpine fir
207 Red fir
210 Interior Douglas-fir
211 White fir
212 Western larch
213 Grand fir
215 Western white pine
216 Blue spruce
218 Lodgepole pine
223 Sitka spruce
224 Western hemlock
225 Western hemlock-Sitka spruce
226 Coastal true fir-hemlock
227 Western redcedar-western hemlock
228 Western redcedar
229 Pacific Douglas-fir
230 Douglas-fir-western hemlock
231 Port-Orford-cedar
232 Redwood
234 Douglas-fir-tanoak-Pacific madrone
237 Interior ponderosa pine
243 Sierra Nevada mixed conifer
244 Pacific ponderosa pine-Douglas-fir
245 Pacific ponderosa pine
249 Canyon live oak
251 White spruce-aspen

SRM (RANGELAND) COVER TYPES [86]:
None

HABITAT TYPES AND PLANT COMMUNITIES:
In Oregon and Washington western rattlesnake plantain is dominant in Douglas-fir (Pseudotsuga menziesii)/tanoak (Lithocarpus densiflora)-canyon live oak (Quercus chrysolepis)/western rattlesnake plantain communities [38]. It is an indicator species for the wild sarsaparilla (Aralia nudicaulis) phase of the subalpine fir/queencup beadlily (Abies lasiocarpa/Clintonia uniflora) habitat type in Montana [46].

In British Columbia, western rattlesnake plantain is a zonal plant indicator for:
Region I - Pacific coastal mesothermal forest; coastal western hemlock (Tsuga heterophylla) and coastal Douglas-fir zones
Region II - Pacific coastal subalpine forest; mountain hemlock (Tsuga mertensiana) zone
Region III - Canadian Cordilleran forest; interior western hemlock zone
Region V - Canadian Cordilleran subalpine forest; Engelmann spruce (Picea engelmannii)-subalpine fir zone [62]

Western rattlesnake plantain is dominant and/or constantly present in the Douglas-fir-western hemlock and the transitional Pacific silver fir (Abies amabilis)-western hemlock subzones of the Vancouver Forest District, British Columbia [59].

Western rattlesnake plantain also occurs with Alaska-cedar (Chamaecyparis nootkatensis), Rocky Mountain maple (Acer glabrum), and Brewer's spruce (Picea breweriana) [32,60,95].


BOTANICAL AND ECOLOGICAL CHARACTERISTICS

SPECIES: Goodyera oblongifolia

 

  2006 Earl Nance
 

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 [30,41,42,49,50,81,85,100].

Western rattlesnake plantain is a native perennial, evergreen forb arising from short creeping rhizomes with fibrous roots. The persistent leaves are arranged in a basal rosette. They are thick, entire, and broadly lance-shaped, 1 to 4 inches (3-10 cm) long on winged petioles. The leaves have white mottling, especially along the mid-vein. There are 2 to 5 cauline leaves on the lower stem. The stems are stout and stiff, glandular pubescent, and have several small membranous bracts. They are 4 to 18 inches (10-45 cm) tall. The flowers are glandular pubescent and borne on a 1-sided or spiraled raceme up to 5 inches (12 cm) long. The petals and 1 of the sepals of the flower form a hood over the lip. There are as many as 30 flowers/raceme, but 10 to 15 are more common. The fruit is an erect, pubescent capsule about 0.4 inch (1 cm) long. Seeds are very small [1,27,49,64,76,77,96].

RAUNKIAER [79] LIFE FORM:
Hemicryptophyte

REGENERATION PROCESSES:
Western rattlesnake plantain regenerates from rhizomes and seeds [78].

Pollination: Bumble bees are the most common pollinators of western rattlesnake plantain. Halictid bees and syrphid flies were observed hovering near Goodyera spp. in northern Michigan. The insects sometimes landed on the flowers but were never seen bearing pollinia. The flowers of western rattlesnake plantain are protandrous, making self-pollination unlikely. Pollination occurs as the bees work their way from the bottom of the inflorescence to the top, removing pollinia from younger, upper flowers in the male stage, then flying to another inflorescence and depositing pollen on lower, older flowers in the female stage [1,55].

Some flowers in the orchid family are nectarless; however, western rattlesnake plantain flowers contain nectar. Nectar increases the chance for successful pollination because pollinators are encouraged to make repeat visits [1,73].

Breeding system: Barriers that restrict interbreeding among species are generally weak in Goodyera spp., making hybridization common in communities with multiple Goodyera species [55]. Western rattlesnake plantain does not self pollinate in the field, however, because the flowers are protandrous. Flowers of western rattlesnake plantain were self-compatible when hand pollinated in a greenhouse study, but showed decreased fertility [1].

Seed production: There are many seeds per capsule (i.e. 4,874 seeds from 10 capsules) [1].

Seed dispersal: The minute seeds of western rattlesnake plantain are wind dispersed [1,54].

Seed banking: A seed bank study in Oregon found no viable western rattlesnake plantain seed in soils where western rattlesnake plantain grew [53]. Further studies are needed on seed banking in western rattlesnake plantain.

Germination: In greenhouse experiments the optimum temperature for germination of western rattlesnake plantain seeds was 77 F (25 C) [5,19].

Seedling establishment/growth: Germinating Goodyera spp. seeds 1st produce slow-growing protocorms (cell masses that develop during orchid germination) that develop rhizoids (root-like structure lacking conductive tissues), and then develop scale-like leaves after several months of growth [92]. Greenhouse studies indicate that once a seed has germinated, it can take up to 1 year before leaves are present and 2.5 years before the plant is fully mature [5].

Vegetative regeneration: Western rattlesnake plantain rapidly regenerates from rhizomes [77].

SITE CHARACTERISTICS:
The following table describes site characteristics for western rattlesnake plantain throughout its distribution.

State, Region, Province Site Characteristic
Alaska mossy forests, young climax forests [26,52]
Arizona north-facing slopes; 8,900 feet (2,700 m) [34]
California dry forest floor, below 5,500 feet (1,700 m) [71]
California dry coniferous forest, in decomposing leaf litter; 1,600 to 7,200 feet (500-2,200 m) [49]
Colorado in duff on fairly dry forest floors [99,100]
Idaho dense woods; 5,000 to 7,200 feet (1,500-2,200 m) [21]
Montana open or deep forests, mossy habitats from valleys to subalpine zones [64]
Oregon cool, moderately dry to moist, mixed conifer sites at all elevations up to subalpine [78,96]
Utah mountain communities at 6,200 to 10,000 feet (1,900-3,100 m) [101]
Great Lakes States dry or moist hardwood or coniferous forests [41]
Pacific Northwest dry to mossy or damp, open to dense forest [50]
Southwest undisturbed forest floor of mixed conifer forests; 8,000 to 9,500 feet (2,400-2,900 m) [75]
British Columbia moderately dry, shady submontane to subalpine areas [61]
Nova Scotia damp mixed forests on slopes and ravines [81]

Soils: In British Columbia, western rattlesnake plantain is an indicator of nitrogen-poor soils [61]. The most common soil moisture regime where western rattlesnake plantain occurs is "dry to fresh", and the soil nutrient regime is "very poor to medium" [60]. Western rattlesnake plantain is restricted to formerly glaciated areas in the East [37].

SUCCESSIONAL STATUS:
Western rattlesnake plantain is characterized as a late-successional species, although it is present in some early seral stages [11,97].

On grand fir (Abies grandis) sites in western Montana, western rattlesnake plantain was prevalent in immature stands (<90 years old), where is showed 89% presence. It was most prevalent in old-growth stands (>150 years old), with 100% presence [4]. Western rattlesnake plantain is present in early stage development Douglas-fir and subalpine fir communities in western Montana, but is much more abundant in the mid- to late-seral stages [11].

Western rattlesnake plantain populations in the Pacific Northwest are most frequent among mature (80-195 years) and old-growth forests (200-730 years) in Douglas-fir/western hemlock zones. Populations were present, however, in young stands (35-79 years) [83]. Spies [87] and Bailey and others [12] also indicate that western rattlesnake plantain is found in young, mature, and old-growth Douglas-fir forests, although it is most frequent in old-growth forests. Halpern and Spies [45] observed that "peak development" of western rattlesnake plantain occurred in old-growth Douglas-fir.

SEASONAL DEVELOPMENT:
Ackerman [1] studied the 10-week flowering period of a large western rattlesnake plantain population located in a late-successional shore pine (Pinus contorta var. contorta) forest in northern California. The study period began August 8th, with anthesis. The flowers lasted approximately 2 weeks, and the capsules matured in 6 to 8 weeks. October 18th marked the end of the 10-week period. Flowering plants usually produced more new rhizomes than nonflowering plants; the mean number of new rhizomes was 1.74 for flowering plants and 0.46 for nonflowering plants [1]. Flowering rosettes deteriorate after blooming, and the rhizome tip dies back [1,23]. The loss is recovered since both flowering and nonflowering individuals produce new rhizome sprouts. Death of the rhizome tip releases buds along the axis of the rhizome from dormancy [23].

The following table provides flowering dates for western rattlesnake plantain throughout its distribution.

State/Region/Province Anthesis Period
California July to August [71]
Idaho July to August [76]
Oregon and Washington July to September [48]
Great Lakes States July to September [41,55]
Pacific Northwest July to August [50]
Ontario August to September [15]

FIRE ECOLOGY

SPECIES: Goodyera oblongifolia
FIRE ECOLOGY OR ADAPTATIONS:
Fire adaptations: Western rattlesnake plantain is poorly adapted to fire. It has succulent rhizomes that grow mostly in the duff layer and are susceptible to fire damage [57,67].

Fire regimes: The warm, moist grand fir, western hemlock, and western redcedar (Thuja plicata) habitat types of western Montana, where western rattlesnake plantain widely occurs, are diverse and highly productive stands with variable fire frequencies and severities. In the event of drought, heavy fuel loading makes the productive sites subject to high-severity, widespread fires where stands are replaced and sites revert back to pioneer species [36].

The drier Douglas-fir and white fir (Abies concolor) series of the eastern Cascade Range, where western rattlesnake plantain is known to occur, have shorter fire-return intervals and lower fire severities. The cooler, wetter grand fir series and some Douglas-fir series have longer fire-return intervals and higher fire severities [2].

The following table provides fire return intervals for plant communities and ecosystems where western rattlesnake plantain is important. For further information, see the FEIS review of the dominant species listed below.

Community or Ecosystem Dominant Species Fire Return Interval Range (years)
silver fir-Douglas-fir Abies amabilis-Pseudotsuga menziesii var. menziesii >200
grand fir Abies grandis 35-200 [6]
western larch Larix occidentalis 25-350 [7,18,29]
Great Lakes spruce-fir Picea-Abies spp. 35 to >200
northeastern spruce-fir Picea-Abies spp. 35-200 [31]
Engelmann spruce-subalpine fir Picea engelmannii-Abies lasiocarpa 35 to >200
blue spruce* Picea pungens 35-200 [6]
Rocky Mountain lodgepole pine* Pinus contorta var. latifolia 25-340 [17,18,94]
Sierra lodgepole pine* Pinus contorta var. murrayana 35-200
western white pine* Pinus monticola 50-200
Pacific ponderosa pine* Pinus ponderosa var. ponderosa 1-47 [6]
interior ponderosa pine* Pinus ponderosa var. scopulorum 2-30 [6,13,65]
Arizona pine Pinus ponderosa var. arizonica 2-15 [13,25,84]
Rocky Mountain Douglas-fir* Pseudotsuga menziesii var. glauca 25-100 [6,8,9]
coastal Douglas-fir* Pseudotsuga menziesii var. menziesii 40-240 [6,68,80]
California mixed evergreen Pseudotsuga menziesii var. menziesii-Lithocarpus densiflorus-Arbutus menziesii <35
canyon live oak Quercus chrysolepis <35 to 200 [6]
redwood Sequoia sempervirens 5-200 [6,35,93]
western redcedar-western hemlock Thuja plicata-Tsuga heterophylla >200
western hemlock-Sitka spruce Tsuga heterophylla-Picea sitchensis >200
mountain hemlock* Tsuga mertensiana 35 to >200 [6]
*fire return interval varies widely; trends in variation are noted in the species review

POSTFIRE REGENERATION STRATEGY [91]:
Rhizomatous herb, rhizome in soil

FIRE EFFECTS

SPECIES: Goodyera oblongifolia
IMMEDIATE FIRE EFFECT ON PLANT:
Western rattlesnake plantain is easily killed by fire because its shallow rhizomes are very sensitive to heat. Fires that consume most of the litter and duff are likely to have a detrimental impact on western rattlesnake plantain [78].

DISCUSSION AND QUALIFICATION OF FIRE EFFECT:
Western rattlesnake plantain's resistance to fire is low. There is less than a 35% chance that 50% of the plants will survive or immediately reestablish after passage of a fire with an average flame length of 12 inches (30 cm) [78].

PLANT RESPONSE TO FIRE:
Western rattlesnake plantain is very sensitive to fire and has minimal postdisturbance recovery in the short term [22,43]. Fire reduces the frequency of western rattlesnake plantain [2,28,57,58,69], and western rattlesnake plantain is not likely to regain its prefire frequency or cover in less than 10 years [78]. As of 2006, no published information was available on whether western rattlesnake plantain recovers after fire from seed, rhizomes, or both. Research is needed on this topic.

DISCUSSION AND QUALIFICATION OF PLANT RESPONSE:
The current body of research details many accounts of western rattlesnake plantain's recovery after fire.

Stickney [89,90] lists western rattlesnake plantain as a "nonsurvivor" after a high-severity wildfire in a western larch-Douglas-fir forest in northwestern Montana. Western rattlesnake plantain, characteristic of nearby unburned areas, was not observed on burned sites after the high-severity Tillamook wildfires in Douglas-fir, western hemlock, and western redcedar forests in northwestern Oregon. The fires burned in 1933, 1939, and again in 1945. Data were recorded during the summers of 1955 and 1956 [72]. A mixed-severity wildfire in a Douglas-fir forest of eastern Washington reduced western rattlesnake plantain percent cover to 0%. Before the fire the percent cover was 1% [47]. Halpern and Spies [45] reported that populations of western rattlesnake plantain among Douglas-fir forests of the H.J. Andrews Experimental Forest, Oregon, were eliminated from all soil disturbance classes including disturbed but unburned, lightly burned, and heavily burned.

Western rattlesnake plantain declined following clearcutting, clearcutting with slash treatments, and wildfire in a subalpine fir/beargrass (Xerophyllum tenax) habitat type in west-central Montana. Slash treatments resulting in western rattlesnake plantain decreases were broadcast burning of logging slash and pile burning following mechanical scarification [10]. Frequency of western rattlesnake plantain decreased in Douglas-fir and tanoak communities after logging, and frequency continued to decrease to 0% after the high-severity Biscuit Fire in southwestern Oregon [22]. On subalpine fir sites in northwestern Montana, western rattlesnake plantain was present before disturbance (logging/slash piling/broadcast burning) and not present in the 1st 8 successional years [88]. According to Marcum [66], western rattlesnake plantain is a "retreater" in response to clearcutting and site treatment (scarification and slash burning). Western rattlesnake plantain was not present for 17 years after these disturbances [66].

After the Waterfalls Canyon Fire in Grand Teton National Park, the mean frequency of western rattlesnake plantain in the 1st growing season was 10% on unburned sites, 3% on moderately burned sites, and 0% on severely burned sites [16]. A prescribed fire on mixed-conifer study sites on the North Rim of Grand Canyon National Park, northern Arizona, escaped and burned with greater severity than expected. Western rattlesnake plantain frequency decreased significantly (p=0.001) on burned sites (33%) vs. unburned sites (83%) [51].

In a greenhouse study, different disturbances were initiated on soil blocks (dug from the western hemlock zone of the H.J. Andrews Experimental Forest) to determine the response of buried propagules to disturbances. Treatments included 0 to 3 combinations of removing shade, churning the soil, burning dry litter on top of the soil for ~30 seconds, and an undisturbed control. Three western rattlesnake plantain sprouts were recorded on the undisturbed plots, and 1 sprout was recorded on the plot that was shaded/churned/burned. No sprouts were observed on any other treatments: full sun/intact/unburned, shade/intact/burned, shade/churned/unburned, sun/intact/burned, sun/churned/unburned, and sun/churned/burned [53].

Hamilton's Research Paper (Hamilton 2006b) provides further information on prescribed fire and postfire response of plant species including western rattlesnake plantain.

FIRE MANAGEMENT CONSIDERATIONS:
Literature to date (2006) provides no clear direction for using fire as a management tool for western rattlesnake plantain populations. The research above, however, indicates that fire will likely reduce western rattlesnake plantain populations. Further research is needed on the fire ecology of western rattlesnake plantain.

MANAGEMENT CONSIDERATIONS

SPECIES: Goodyera oblongifolia
IMPORTANCE TO LIVESTOCK AND WILDLIFE:
Western rattlesnake plantain can be an important component of the diets of white-tailed deer in northwestern Montana and woodland caribou in northeastern Washington [70,82]. White-tailed deer in the Swan Valley of northwestern Montana eat western rattlesnake plantain in winter [70]. Western rattlesnake plantain was 1 of 3 vascular plants that contributed most to the diets of woodland caribou in old-growth western redcedar-western hemlock stands in northeastern Washington [82].

Palatability/nutritional value: No information is available on this topic.

Cover value: No information is available on this topic.

VALUE FOR REHABILITATION OF DISTURBED SITES:
No information is available on this topic.

OTHER USES:
Native Americans and early settlers thought western rattlesnake plantain was a cure for rattlesnakes bites because the markings on the leaves resembled snakeskin markings; hence the common name [76,77]. Western rattlesnake plantain was known to some Native Americans as a medicine for childbirth, and as a poultice for cuts and sores for which the leaves were split open and the moist inner part placed over the wound [77].

OTHER MANAGEMENT CONSIDERATIONS:
In a study done on the disturbance and recovery of trampled montane grasslands and forests in Montana, western rattlesnake plantain had a medium score (200-400 passes/year required to reduce the frequency of occurrence) for resistance. Short-term (end of the 1st trampling season and the start of the 2nd trampling season) and long-term (end of the last trampling season and the end of the recovery period three years later) resilience were both rated as low, with <10% increase in relative cover. It was also reported that after short- (one season of trampling and one 10-month recovery period) and long-term (three seasons of trampling and 3 years of recovery) recovery periods, western rattlesnake plantain could only tolerate light trampling (75-100 passes) and still recover [24].

Production of western rattlesnake plantain decreased on grazed vs. ungrazed plots with 18.80 kg/ha and 34.10 kg/ha, respectively. The study area was a Douglas-fir/ninebark (Physocarpus malvaceus) habitat type on the University of Idaho Experimental Forest [102].

Western rattlesnake plantain is negatively affected by harvesting. It was consistently found on uncut Douglas-fir sites of the western Cascade Range in Oregon and not found after logging [40]. Gashwiler [40] states that western rattlesnake plantain survival is difficult or impossible under clearcut conditions. In western Washington and western Oregon, western rattlesnake plantain was extirpated from all harvested plots sampled. Plots were monitored for >25 years after harvest [44]. In southern Washington's western hemlock zone, the relative change in cover of western rattlesnake plantain in harvested areas vs. forest aggregates was significantly (p=0.002) lower 2 years after treatment compared to pretreatment cover[74].

REFERENCES:


1. Ackerman, James D. 1975. Reproductive biology of Goodyera oblongifolia (Orchidaceae). Madrono. 23: 191-198. [64246]
2. Agee, James K. 1994. Fire and weather disturbances in terrestrial ecosystems of the eastern Cascades. Gen. Tech. Rep. PNW-GTR-320. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 52 p. [Hessburg, Paul F., tech. ed. Eastside forest ecosystem health assessment. Vol. 3: assessment]. [23656]
3. Anderson, J. P. 1959. Flora of Alaska and adjacent parts of Canada. Ames, IA: Iowa State University Press. 543 p. [9928]
4. Antos, J. A.; Habeck, J. R. 1981. Successional development in Abies grandis (Dougl.) Forbes forests in the Swan Valley, western Montana. Northwest Science. 55(1): 26-39. [12445]
5. Arditti, Joseph; Oliva, Allison P.; Michaud, Justine D. 1982. Practical germination of North American and related orchids--II. Goodyera oblongifolia and G. tesselata. American Orchid Society Bulletin. 51: 394-397. [64253]
6. Arno, Stephen F. 2000. Fire in western forest ecosystems. In: Brown, James K.; Smith, Jane Kapler, eds. Wildland fire in ecosystems: Effects of fire on flora. Gen. Tech. Rep. RMRS-GTR-42-vol. 2. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station: 97-120. [36984]
7. Arno, Stephen F.; Fischer, William C. 1995. Larix occidentalis--fire ecology and fire management. In: Schmidt, Wyman C.; McDonald, Kathy J., comps. Ecology and management of Larix forests: a look ahead: Proceedings of an international symposium; 1992 October 5-9; Whitefish, MT. Gen. Tech. Rep. GTR-INT-319. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 130-135. [25293]
8. Arno, Stephen F.; Gruell, George E. 1983. Fire history at the forest-grassland ecotone in southwestern Montana. Journal of Range Management. 36(3): 332-336. [342]
9. Arno, Stephen F.; Scott, Joe H.; Hartwell, Michael G. 1995. Age-class structure of old growth ponderosa pine/Douglas-fir stands and its relationship to fire history. Res. Pap. INT-RP-481. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 25 p. [25928]
10. Arno, Stephen F.; Simmerman, Dennis G. 1982. Succession after cutting and fire treatments on forest habitat types in western Montana. In: Baumgartner, David M., compiler. Site preparation and fuels management on steep terrain: Proceedings of a symposium; 1982 February 15-17; Spokane, WA. Pullman, WA: Washington State University, Cooperative Extension: 113-117. [18537]
11. Arno, Stephen F.; Simmerman, Dennis G.; Keane, Robert E. 1985. Forest succession on four habitat types in western Montana. Gen. Tech. Rep. INT-177. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station. 74 p. [349]
12. Bailey, John D.; Mayrsohn, Cheryl; Doescher, Paul S.; St. Pierre, Elizabeth; Tappeiner, John C. 1998. Understory vegetation in old and young Douglas-fir forests of western Oregon. Forest Ecology and Management. 112(3): 289-302. [30086]
13. Baisan, Christopher H.; Swetnam, Thomas W. 1990. Fire history on a desert mountain range: Rincon Mountain Wilderness, Arizona, U.S.A. Canadian Journal of Forest Research. 20: 1559-1569. [14986]
14. Banner, Allen; Pojar, Jim; Trowbridge, Rick; Hamilton, Anthony. 1986. Grizzly bear habitat in the Kimsquit River Valley, coastal British Columbia: classification, description, and mapping. In: Contreras, Glen P.; Evans, Keith E., compilers. Proceedings--grizzly bear habitat symposium; 1985 April 30 - May 2; Missoula, MT. Gen. Tech. Rep. INT-207. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 36-49. [10810]
15. Barclay-Estrup, P.; Duralia, T. E.; Harris, A. G. 1991. Flowering sequence of the orchid genus Goodyera in Thunder Bay, Alaska. Rhodora. 93(874): 141-147. [15379]
16. Barmore, William J., Jr.; Taylor, Dale; Hayden, Peter. 1976. Ecological effects and biotic succession following the 1974 Waterfalls Canyon Fire in Grand Teton National Park. Research Progress Report 1974-1975. Unpublished report on file at: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, MT. 99 p. [16109]
17. Barrett, Stephen W. 1993. Fire regimes on the Clearwater and Nez Perce National Forests north-central Idaho. Final Report: Order No. 43-0276-3-0112. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station, Fire Sciences Laboratory. Unpublished report on file with: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, MT. 21 p. [41883]
18. Barrett, Stephen W.; Arno, Stephen F.; Key, Carl H. 1991. Fire regimes of western larch - lodgepole pine forests in Glacier National Park, Montana. Canadian Journal of Forest Research. 21: 1711-1720. [17290]
19. Baskin, Carol C.; Baskin, Jerry M. 2001. Seeds: ecology, biogeography, and evolution of dormancy and germination. San Diego, CA: Academic Press. 666 p. [60775]
20. Bernard, Stephen R.; Brown, Kenneth F. 1977. Distribution of mammals, reptiles, and amphibians by BLM physiographic regions and A.W. Kuchler's associations for the eleven western states. Tech. Note 301. Denver, CO: U.S. Department of the Interior, Bureau of Land Management. 169 p. [434]
21. Bingham, Richard T. 1987. Plants of the Seven Devils Mountains of Idaho--an annotated checklist. General Technical Report INT-219. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 146 p. [447]
22. Bormann, Bernard T.; Darbyshire, Robyn. 2005. Ecosystem effects of the Biscuit Fire. In: Taylor, Lagene; Zelnik, Jessica; Cadwallader, Sara; Hughes, Brian, comps. Mixed severity fire regimes: ecology and management: symposium proceedings; 2004 November 17-19; Spokane, WA. Pullman, WA: Washington State University Extension: 79-88. [61399]
23. Case, Frederick W., Jr. 1988. The jewel orchids of North America. American Orchid Society Bulletin. 57(7): 758-765. [62674]
24. Cole, David N. 1988. Disturbance and recovery of trampled montane grassland and forests in Montana. Res. Pap. INT-389. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 37 p. [3622]
25. Cooper, Charles F. 1960. Changes in vegetation, structure, and growth of southwestern pine forests since white settlement. Ecological Monographs. 30(2): 129-164. [3927]
26. Cooper, William S. 1939. Additions to the flora of the Glacier Bay National Monument, Alaska, 1935-1936. Bulletin of the Torrey Botanical Club. 66(7): 453-456. [64250]
27. Cronquist, Arthur; Holmgren, Arthur H.; Holmgren, Noel H.; Reveal, James L.; Holmgren, Patricia K. 1977. Intermountain flora: Vascular plants of the Intermountain West, U.S.A. Vol. 6: The Monocotyledons. New York: Columbia University Press. 584 p. [719]
28. Daubenmire, Rexford F.; Daubenmire, Jean B. 1968. Forest vegetation of eastern Washington and northern Idaho. Technical Bulletin 60. Pullman, WA: Washington State University, College of Agriculture; Washington Agricultural Experiment Station. 104 p. [749]
29. Davis, Kathleen M. 1980. Fire history of a western larch/Douglas-fir forest type in northwestern Montana. In: Stokes, Marvin A.; Dieterich, John H., tech. coords. Proceedings of the fire history workshop; 1980 October 20-24; Tucson, AZ. Gen. Tech. Rep. RM-81. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station: 69-74. [12813]
30. Dorn, Robert D. 1977. Flora of the Black Hills. Cheyenne, WY: Robert D. Dorn and Jane L. Dorn. 377 p. [820]
31. Duchesne, Luc C.; Hawkes, Brad C. 2000. Fire in northern ecosystems. In: Brown, James K.; Smith, Jane Kapler, eds. Wildland fire in ecosystems: Effects of fire on flora. Gen. Tech. Rep. RMRS-GTR-42-vol. 2. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station: 35-51. [36982]
32. Dyrness, C. T.; Franklin, J. F.; Moir, W. H. 1974. A preliminary classification of forest communities in the central portion of the western Cascades in Oregon. Bulletin No. 4. Seattle, WA: University of Washington, Ecosystem Analysis Studies, Coniferous Forest Biome. 123 p. [8480]
33. Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Washington, DC: Society of American Foresters. 148 p. [905]
34. Fernandes, G. Wilson. 1992. A gradient analysis of plant forms from northern Arizona. Journal of the Arizona-Nevada Academy of Science. 24-25: 21-30. [18247]
35. Finney, Mark A.; Martin, Robert E. 1989. Fire history in a Sequoia sempervirens forest at Salt Point State Park, California. Canadian Journal of Forest Research. 19: 1451-1457. [9845]
36. Fischer, William C.; Bradley, Anne F. 1987. Fire ecology of western Montana forest habitat types. Gen. Tech. Rep. INT-223. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 95 p. [633]
37. Flora of North America Editorial Committee, eds. 2011. Flora of North America North of Mexico [Online]. Flora of North America Association (Producer). Available: http://www.efloras.org/flora_page.aspx?flora_id=1. [36990]
38. Franklin, Jerry F.; Dyrness, C. T. 1973. Natural vegetation of Oregon and Washington. Gen. Tech. Rep. PNW-8. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 417 p. [961]
39. Garrison, George A.; Bjugstad, Ardell J.; Duncan, Don A.; Lewis, Mont E.; Smith, Dixie R. 1977. Vegetation and environmental features of forest and range ecosystems. Agric. Handb. 475. Washington, DC: U.S. Department of Agriculture, Forest Service. 68 p. [998]
40. Gashwiler, Jay S. 1970. Plant and mammal changes on a clearcut in west-central Oregon. Ecology. 51(6): 1018-1026. [8523]
41. 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. [20329]
42. 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. [23307]
43. Halpern, C. B. 1989. Early successional patterns of forest species: interactions of life history traits and disturbance. Ecology. 70(3): 704-720. [6829]
44. Halpern, Charles B.; McKenzie, Donald; Evans, Shelley A.; Maguire, Douglas A. 2005. Initial responses of forest understories to varying levels and patterns of green-tree retention. Ecological Applications. 15(1): 175-195. [61472]
45. Halpern, Charles B.; Spies, Thomas A. 1995. Plant species diversity in natural and managed forests of the Pacific Northwest. Ecological Applications. 5(4): 913-934. [62677]
46. Hansen, Paul; Boggs, Keith; Pfister, Robert; Joy, John. 1990. Classification and management of riparian and wetland sites in central and eastern Montana. Draft Version 2. Missoula, MT: University of Montana, School of Forestry, Montana Forest and Conservation Experiment Station, Montana Riparian Association. 279 p. [12477]
47. Harrod, Richy J.; Knecht, Dottie E.; Kuhlmann, Ellen E.; Ellis, Mark W.; Davenport, Roberta. 1997. Effects of the Rat and Hatchery Creek fires on four rare plant species. In: Greenlee, Jason M., ed. Proceedings, 1st conference on fire effects on rare and endangered species and habitats; 1995 November 13-16; Coeur d'Alene, ID. Fairfield, WA: International Association of Wildland Fire: 311-319. [28155]
48. Healey, Patrick L.; Michaud, Justine D.; Arditti, Joseph. 1980. Morphometry of orchid seeds. III. Native California and related species of Goodyera, Piperia, Platanthera and Spiranthes. American Journal of Botany. 67(4): 508-518. [62682]
49. Hickman, James C., ed. 1993. The Jepson manual: Higher plants of California. Berkeley, CA: University of California Press. 1400 p. [21992]
50. Hitchcock, C. Leo; Cronquist, Arthur; Ownbey, Marion. 1969. Vascular plants of the Pacific Northwest. Part 1: Vascular cryptogams, gymnosperms, and monocotyledons. Seattle, WA: University of Washington Press. 914 p. [1169]
51. Huisinga, Kristin D.; Laughlin, Daniel C.; Fule, Peter Z.; Springer, Judith D.; McGlone, Christopher M. 2005. Effects of an intense prescribed fire on understory vegetation in a mixed conifer forest. Journal of the Torrey Botanical Society. 132(4): 590-601. [61876]
52. Hulten, Eric. 1968. Flora of Alaska and neighboring territories. Stanford, CA: Stanford University Press. 1008 p. [13403]
53. Ingersoll, Cheryl A.; Wilson, Mark V. 1990. Buried propagules in an old-growth forest and their response to experimental disturbances. Canadian Journal of Botany. 68: 1156-1162. [11767]
54. Kallunki, Jacquelyn A. 1976. Population studies in Goodyera (Orchidaceae) with emphasis on the hybrid origin of G. tesselata. Brittonia. 28(1): 53-75. [62676]
55. Kallunki, Jacquelyn A. 1981. Reproductive biology of mixed-species populations of Goodyera (Orchidaceae) in northern Michigan. Brittonia. 33(2): 137-155. [62675]
56. 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. [36715]
57. Keown, Larry D. 1978. Fire management in the Selway-Bitterroot Wilderness, Moose Creek Ranger District, Nez Perce National Forest. Missoula, MT: U.S. Department of Agriculture, Forest Service, Northern Region. Unpublished report on file with: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, MT. 163 p. [18634]
58. Kilgore, Bruce M. 1973. Impact of prescribed burning on a Sequoia-mixed conifer forest. In: Proceedings, annual Tall Timbers fire ecology conference; 1972 June 8-10; Lubbock, TX. No. 12. Tallahassee, FL: Tall Timbers Research Station: 345-375. [6270]
59. Klinka, K. 1977. Guide for the tree species selection and prescribed burning in the Vancouver Forest District: Second approximation. Vancouver, BC: Ministry of Forests, Forest Service Research Division, Vancouver Forest District. 56 p. [16924]
60. Klinka, K.; Green, R. N.; Courtin, P. J.; Nuszdorfer, F. C. 1984. Site diagnosis, tree species selection, and slashburning guidelines for the Vancouver Forest Region, British Columbia. Land Management Report No. 25. Victoria, BC: Ministry of Forests, Information Services Branch. 180 p. [15448]
61. Klinka, K.; Krajina, V. J.; Ceska, A.; Scagel, A. M. 1989. Indicator plants of coastal British Columbia. Vancouver, BC: University of British Columbia Press. 288 p. [10703]
62. Krajina, Vladimir J. 1965. Biogeoclimatic zones and biogeocoenoses of British Columbia. Ecology of Western North America. 1: 1-17. [51764]
63. Kuchler, A. W. 1964. Manual to accompany the map of potential vegetation of the conterminous United States. Special Publication No. 36. New York: American Geographical Society. 77 p. [1384]
64. 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. [13798]
65. Laven, R. D.; Omi, P. N.; Wyant, J. G.; Pinkerton, A. S. 1980. Interpretation of fire scar data from a ponderosa pine ecosystem in the central Rocky Mountains, Colorado. In: Stokes, Marvin A.; Dieterich, John H., tech. coords. Proceedings of the fire history workshop; 1980 October 20-24; Tucson, AZ. Gen. Tech. Rep. RM-81. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station: 46-49. [7183]
66. Marcum, Les. 1971. Vegetal development on montane fir clearcuts in western Montana. Missoula, MT: University of Montana. 122 p. Thesis. [36494]
67. McLean, Alastair. 1968. Fire resistance of forest species as influenced by root systems. Journal of Range Management. 22(2): 120-122. [1621]
68. Morrison, Peter H.; Swanson, Frederick J. 1990. Fire history and pattern in a Cascade Range landscape. Gen. Tech. Rep. PNW-GTR-254. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 77 p. [13074]
69. Mueggler, Walter F. 1965. Ecology of seral shrub communities in the cedar-hemlock zone of northern Idaho. Ecological Monographs. 35: 165-185. [4016]
70. Mundinger, John D. 1978. Population ecology and habitat relationships of white-tailed deer in coniferous forest habitat of northwestern Montana. Montana deer studies: Job progress report 1977-1978. Helena, MT: Montana Department of Fish and Game. 74 p. [21525]
71. Munz, Philip A.; Keck, David D. 1973. A California flora and supplement. Berkeley, CA: University of California Press. 1905 p. [6155]
72. Neiland, Bonita J. 1958. Forest and adjacent burn in the Tillamook Burn area of northwestern Oregon. Ecology. 39(4): 660-671. [8879]
73. Neiland, Mary Ruth M.; Wilcock, Christopher C. 1998. Fruit set, nectar reward, and rarity in the Orchidaceae. American Journal of Botany. 85(12): 1657-1671. [62695]
74. Nelson, Cara R.; Halpern, Charles B. 2005. Edge-related responses of understory plants to aggregated retention harvest in the Pacific Northwest. Ecological Applications. 15(1): 196-209. [61474]
75. Pase, Charles P.; Brown, David E. 1982. Rocky Mountain (Petran) and Madrean montane conifer forests. In: Brown, David E., ed. Biotic communities of the American Southwest--United States and Mexico. Desert Plants. 4(1-4): 43-48. [8885]
76. Patterson, Patricia A.; Neiman, Kenneth E.; Tonn, Jonalea. 1985. Field guide to forest plants of northern Idaho. Gen. Tech. Rep. INT-180. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 246 p. [1839]
77. 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. [25159]
78. Powell, David C. 1994. Effects of the 1980's western spruce budworm outbreak on the Malheur National Forest in northeastern Oregon. Tech. Pub. R6-FI&D-TP-12-94. Portland, OR: U.S. Department of Agriculture, Forest Service, Natural Resources Staff, Forest Insects and Diseases Group. 176 p. [29717]
79. Raunkiaer, C. 1934. The life forms of plants and statistical plant geography. Oxford: Clarendon Press. 632 p. [2843]
80. Ripple, William J. 1994. Historic spatial patterns of old forests in western Oregon. Journal of Forestry. 92(11): 45-49. [33881]
81. Roland, A. E.; Smith, E. C. 1969. The flora of Nova Scotia. Halifax, NS: Nova Scotia Museum. 746 p. [13158]
82. Rominger, Eric M.; Robbins, Charles T.; Evans, Marc A.; Pierce, D. John. 2000. Autumn foraging dynamics of woodland caribou in experimentally manipulated habitats, northeastern Washington, USA. Journal of Wildlife Management. 64(1): 160-167. [37008]
83. Ruggiero, Leonard F.; Jones, Lawrence L. C.; Aubry, Keith B. 1991. Plant and animal habitat associations in Douglas-fir forests of the Pacific Northwest: an overview. In: Ruggiero, Leonard F.; Aubry, Keith B.; Carey, Andrew B.; Huff, Mark H., technical coordinators. Wildlife and vegetation of unmanaged Douglas-fir forests. Gen. Tech. Rep. PNW-GTR-285. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station: 447-462. [17334]
84. Seklecki, Mariette T.; Grissino-Mayer, Henri D.; Swetnam, Thomas W. 1996. Fire history and the possible role of Apache-set fires in the Chiricahua Mountains of southeastern Arizona. In: Ffolliott, Peter F.; DeBano, Leonard F.; Baker, Malchus B., Jr.; Gottfried, Gerald J.; Solis-Garza, Gilberto; Edminster, Carleton B.; Neary, Daniel G.; Allen, Larry S.; Hamre, R. H., tech. coords. Effects of fire on Madrean Province ecosystems: a symposium proceedings; 1996 March 11-15; Tucson, AZ. Gen. Tech. Rep. RM-GTR-289. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station: 238-246. [28082]
85. 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. [7604]
86. Shiflet, Thomas N., ed. 1994. Rangeland cover types of the United States. Denver, CO: Society for Range Management. 152 p. [23362]
87. Spies, Thomas A. 1991. Plant species diversity and occurrence in young, mature, and old-growth Douglas-fir stands in western Oregon and Washington. In: Ruggiero, Leonard F.; Aubry, Keith B.; Carey, Andrew B.; Huff, Mark H., technical coordinators. Wildlife and vegetation of unmanaged Douglas-fir forests. Gen. Tech. Rep. PNW-GTR-285. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station: 111-121. [17309]
88. Stickney, Peter F. 1980. Data base for post-fire succession, first 6 to 9 years, in Montana larch-fir forests. Gen. Tech. Rep. INT-62. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station. 133 p. [6583]
89. Stickney, Peter F. 1982. Initial stages of a natural forest succession following wildfire in the northern Rocky Mountains, a case study. Unpublished report on file with: U.S. Department of Agriculture, Forest Service, Intermountain Research Station, Fire Sciences Laboratory, Missoula, MT. 2 p. [20956]
90. Stickney, Peter F. 1985. Initial stages of a natural forest succession following wildfire in the Northern Rocky Mountains, a case study. In: Lotan, James E.; Kilgore, Bruce M.; Fischer, William C.; Mutch, Robert W., technical coordinators. Proceedings--symposium and workshop on wilderness fire; 1983 November 15-18; Missoula, MT. Gen. Tech. Rep. INT-181. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 383-384. [7367]
91. 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, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, MT. 10 p. [20090]
92. Stoutamire, Warren P. 1964. Seeds and seedlings of native orchids. The Michigan Botanist. 3: 107-119. [64251]
93. Stuart, John D. 1987. Fire history of an old-growth forest of Sequoia sempervirens (Taxodiaceae) forest in Humboldt Redwoods State Park, California. Madrono. 34(2): 128-141. [7277]
94. Tande, Gerald F. 1979. Fire history and vegetation pattern of coniferous forests in Jasper National Park, Alberta. Canadian Journal of Botany. 57: 1912-1931. [18676]
95. Thornburgh, Dale. 1990. Picea breweriana Wats. Brewer spruce. In: Burns, Russell M.; Honkala, Barbara H., technical coordinators. Silvics of North America. Volume 1. Conifers. Agric. Handb. 654. Washington, DC: U.S. Department of Agriculture, Forest Service: 181-186. [13383]
96. Topik, Christopher; Hemstrom, Miles A., comps. 1982. Guide to common forest-zone plants: Willamette, Mt. Hood, and Siuslaw National Forests. R6-Ecol 101-1982. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Region. 95 p. [3234]
97. Traut, Bibit Halliday; Muir, Patricia S. 2000. Relationships of remnant trees to vascular undergrowth communities in the western Cascades: a retrospective approach. Northwest Science. 74(3): 212-223. [39449]
98. U.S. Department of Agriculture, Natural Resources Conservation Service. 2011. PLANTS Database, [Online]. Available: http://plants.usda.gov/. [34262]
99. Weber, William A. 1987. Colorado flora: western slope. Boulder, CO: Colorado Associated University Press. 530 p. [7706]
100. Weber, William A.; Wittmann, Ronald C. 1996. Colorado flora: eastern slope. 2nd ed. Niwot, CO: University Press of Colorado. 524 p. [27572]
101. 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. [2944]
102. Zimmerman, G. T.; Neuenschwander, L. F. 1984. Livestock grazing influences on community structure, fire intensity, and fire frequency within the Douglas-fir/ninebark habitat type. Journal of Range Management. 37(2): 104-110. [10103]

FEIS Home Page