Research Project Summary: Vegetation response to restoration treatments in ponderosa pine-Douglas-fir forests of western Montana

Metlen, Kerry L.; Dodson, Erich K.; Fiedler, Carl E. 2006. Research Project Summary: Vegetation response to restoration treatments in ponderosa pine-Douglas-fir forests of western Montana. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: [ ].

See the Appendix.

The study site is located at the University of Montana's Lubrecht Experimental Forest (4653' N, 11326' W), Missoula County, Montana, USA. This study is 1 of 13 in a nationwide network of Fire/Fire Surrogate (FFS) studies investigating the interdisciplinary effects of treatments designed to reduce fire hazard and restore the structure and function of fire-adapted forests.

The mean yearly temperature at Lubrecht forest is 45 F, and mean annual precipitation is 22 inches - nearly half falling as snow [7]. The Lubrecht study employed a randomized block design, with 3 blocks and 4 treatments (control, burn-only, thin-only, and thin-burn). Three, 90-acre blocks were delineated in moderately dense ponderosa pine-Douglas-fir forests on gentle to moderate slopes within 2.5 miles proximity. Each block was divided into 4 square treatment units of 22-acres each, with 1 replicate of each treatment in each block. Existing firebreaks predetermined the assignment of 1 burn treatment in 2 blocks; all other treatments were assigned randomly. A 6 6 grid of reference points (36 total) at 164-foot intervals was permanently established in each treatment unit. Site characteristics are summarized by block and treatment in the following table:

Treatment Block Elevation (feet) Aspect (degrees) Slope (degrees) Habitat type* [8] Soil series
Control 1 4313 125 13 PSME/VACA Winkler
Control 2 4137 75 5 PSME/VACA Tevis-Mitten
Control 3 4097 59 5 PSME/VACA Bignell
Burn-only 1 4415 127 10 PSME/VACA Winkler
Burn-only 2 4215 336 5 PSME/VACA Tevis-Mitten
Burn-only 3 4147 303 5 PSME/VACA Bignell
Thin-only 1 4270 138 9 PSME/VACA Winkler
Thin-only 2 4156 3 8 PSME/VACA Tevis-Mitten
Thin-only 3 4127 98 8 PSME/VACA Bignell
Thin-burn 1 4457 123 10 PSME/SPBE Winkler
Thin-burn 2 4274 11 8 PSME/VACA Tevis-Mitten
Thin-burn 3 4084 263 7 PSME/VACA Bignell
*PSME=Pseudotsuga menziesii var. glauca, SPBE=Spiraea betulifolia,VACA=Vaccinium caespitosum

This study occurs in the following vegetation classifications:

FRES21 Ponderosa pine
FRES20 Douglas-fir

K011 Western ponderosa forest

237 Interior ponderosa pine
212 Western larch
210 Interior Douglas-fir

The research stands were primarily ponderosa pine and Douglas-fir in composition, with scattered western larch and lodgepole pine. Measured in basal area, species composition of the pretreatment stands was approximately 60% seral species (primarily ponderosa pine) and 40% shade-tolerant Douglas-fir. These stands regenerated following heavy harvesting in the early 1900s, in which nearly all merchantable-sized trees were removed. Most 2nd-growth trees were ~90 years old, with scattered clumps of regeneration and occasional trees >200 years old. All treatment areas had uneven-aged diameter distributions prior to treatment, with individual tree diameters ranging from 4 inches to 27 inches diameter at breast height (DBH). Typical of ponderosa forests in the region, the study area has been subject to moderate grazing over the last 100 years.

Regeneration of shade-tolerant Douglas-fir was abundant in the understory, while the most abundant undergrowth species included heartleaf arnica, white spirea, common snowberry, pinegrass, and elk sedge.

Vegetation was sampled on modified Whittaker plots randomly located at 10 of the 36 reference points in each unit. Each 66 foot x 164 foot (0.25-acre) Whittaker plot was subdivided into ten, 33-foot 33-foot (0.025-acre) subplots with two 3.3 foot 3.3 foot (0.00025-acre) quadrats in opposite corners of each subplot. We identified all understory species on each 0.25-acre plot and sampled DBH of all trees >4 inches DBH. Saplings (trees >4.5 feet tall but <4.0 inches DBH) were tallied in five randomly selected 0.025-acre subplots within each plot. Twelve of the twenty quadrats (0.00025-acre) in each plot were randomly selected to sample understory richness and cover. All sampling locations were permanently marked with metal stakes to ensure accurate plot relocation in future sampling years.

Burns conducted in the spring coincide well with typical low-elevation prescribed underburning in western Montana. When the 1st broadcast burn was implemented in early May, buds were swelling in the overstory trees and the understory vegetation was just beginning to "greenup." The last burn (conducted in late June) was outside the normal spring burning season with significant "greenup," new conifer foliage extensively elongated, and many species in full flower.

All 6 burns (3 in thinned units; 3 in unthinned units) were implemented in the spring of 2002 and were generally of low to moderate severity. Each 22-acre burn was completed in a single day. Silvicultural cuttings ("thinnings") were conducted in the winter of 2000/2001 over snow-covered soil. The following table contains treatment dates and burn severity (measured as degree of ground char).

Treatment Block Burn date Harvest date Area of a given burn severity* (%)
None Low Moderate High
5/15/2002 n.a. 40 54 4 2
6/25/2002 n.a. 39 35 13 13
6/14/2002 n.a. 31 66 2 1
n.a. 3/01 n.a. n.a. n.a. n.a.
n.a. 2/01 n.a. n.a. n.a. n.a.
n.a. 2/01 n.a. n.a. n.a. n.a.
5/1/2002 2/01 34 47 16 3
6/6/2002 1/01 48 37 11 4
5/31/2002 2/01 15 65 17 3
*Burn severity: None = No duff burned, Low = Partial duff burned,
Moderate = Most/all duff burned, High = All duff and much woody fuel burned

Our "low," "moderate," and "high" burn severity categories correspond well to Burned Area Emergency Response (BAER) severity classifications "lightly," "moderately," and "heavily" burned, respectively. Some of our low-severity areas fell under the BAER "scorch" category, but burn prescriptions were conducted under conditions such that these instances were limited.

Restoration treatments were designed to initiate the long-term process of moving stand density, structure, and species composition toward historical conditions, and to reduce the potential for stand-replacing fire. The objective of burning in the thin-burn treatment was to reduce the unnaturally high surface fuel loads resulting from the thinning operation while causing minimal overstory mortality. The objective of the burn-only treatment was to reduce the amount and continuity of canopy fuels and inflict significant tree mortality, especially in small and medium size classes. While pretreatment surface fuel loads were relatively modest, abundant canopy fuels precluded accomplishing long-term fuel reduction and stand structure objectives with a single burn. Burn prescriptions (see table below) were designed to balance concerns for safety, control, and fire behavior with the desire to restore historical structure and function to the forest.

General burn prescription parameters
Air temperature 55-80 F
Relative humidity (RH) 20-45%
Midflame wind speed 0-8 mph
Maximum gusts 12 mph
1-Hr fuel moisture 6-12%
10-Hr fuel moisture 8-18%
100-Hr fuel moisture 12-20%
1000-Hr fuel moisture 50-100%
Duff moisture 40-80%

The restoration cutting prescription set an average target reserve basal area of 48 feet/acre. Target stand structures were uneven-aged, with a long-term goal of one-half to two-thirds of the basal area in trees >20 inches DBH. Target species composition over the long-term is >90% basal area composition of ponderosa pine.

Units receiving cutting treatments were leave-tree marked. Low thinning removed most pole-sized trees (ladder fuels), improvement cutting removed most shade-tolerant Douglas-fir from the mid- and upper canopy, and selection cutting reduced overall stand density enough to induce regeneration of shade-intolerant ponderosa pine. A cut-to-length system was used to cut and limb trees on site, leaving nonmerchantable materials in place as a buffer between logging equipment and the soil. Merchantable timber was transported from the stand to a landing area using rubber-tired forwarders. This harvest system, coupled with winter logging, resulted in no significant soil compaction or exposed mineral soil [4].

Prescribed burning was initiated in all burn units using strip headfires to control fire intensity. Firing was slow in the thin-burn units to minimize overstory damage, but was increased in the burn-only units to induce tree mortality. Variation in weather conditions among burn days and in the volume and spatial distribution of fuels within each 22-acre unit led to variation in fire behavior among and within the 6 burn units:

Treatment Burn-only Thin-burn
Block 1 2 3 1 2 3
Wind speed (mph) 1-3 1-3 1-3 2-5 4-8 3-6
Relative humidity range (%) 35-46 26-48 20-41 28-42 27-45 20-29
Temperature range (F) 48-53 67-85 67-83 53-56 57-64 64-80
Flame length (feet) Nonslash 1-4 0.5-2 0.5-2 1-2 1-2 0.5-1
Slash n.a. n.a. n.a. 3-9 2-9 2-8
Flame depth (feet) Nonslash 2-6 1-2 1-3 1-3 1-3 1-2
Slash n.a. n.a. n.a. 4-10 3-10 4-10
Fine fuels* consumed (%) 56 58 40 71 66 71
Fine fuels* consumed (tons/acre) 1.3 1.9 0.7 6.5 6.7 9.9
Duff (Oe, Oa) consumed (%) 17.4 13.3 2 14.2 10.4 14.4
*Fine fuels diameter <3 inches

All variables are presented as untransformed values. Statistical tests were conducted on both pretreatment and change (posttreatment-pretreatment) data and P-values <0.05 were considered significant. Sapling density was significantly reduced by all active treatments, with the greatest reduction in the thin-burn treatment [6]. Restoration cutting resulted in significant overstory density reductions and achieved target basal areas to the nearest 0.5 feet/acre (averaged across the 22-acre units). Subsequent wind- and burning-related mortality further reduced overstory density and accentuated patchiness, particularly in the thin-burn treatments. Cutting increased proportional basal area composition of seral tree species (from about 60% to 75%). Density of trees and saplings before treatment and in 2003 (1 year after burning/2 years after harvest) are summarized in the following table:

Year Control Burn-only Thin-only Thin-burn
Saplings/acre Pre 805 881 537 425
2003 929 530 428 58
Trees/acre Pre 163 179 158 143
2003 161 166 61 55
Basal area (feet/acre) Pre 104 99 89 91
2003 103 94 48 42

Understory richness increased significantly more in the thin-only and thin-burn treatments than in the burn-only and control. Forb and nonnative species richness increased more in all active treatments, particularly the thin-burn, than in the control. Native species richness increased significantly in the 2 treatments that included cutting. Mean plot-scale (0.25-acre) richness for all species (total), native species, nonnative species, graminoids, forbs, shrubs, and trees are summarized in the following table by treatment and year, with 1 standard error in parentheses. Letters represent significant differences between treatments, within years. See Metlen and Fiedler [6] for methods and details about richness and cover at the smaller spatial scale (0.00025-acre).

Plot-scale richness Year Control Burn-only Thin-only Thin-burn P
Total Pre 36.3 (1.3) 34.5 (3.9) 37.3 (2.3) 36.1 (3.1) 0.606
2004 57.3 (2.7)a 59.7 (7.1)ab 66.2 (4.1)bc 68.6 (7.7)c 0.024*
Natives Pre 34.1 (0.6) 32.9 (3.2) 34.8 (1.7) 33.5 (2.0) 0.632
2004 52.8 (1.8)a 53.7 (5.2)ab 59.3 (3.0)b 58.4 (5.1)b 0.036*
Exotics Pre 2.2 (0.7) 1.6 (0.8) 2.3 (0.7) 2.6 (1.1) 0.440
2004 4.4 (0.9)a 5.9 (2.0)b 6.9 (1.1)b 10.2 (2.7)c 0.040*
Graminoids Pre 6.1 (0.2) 5.4 (0.4) 6.8 (0.5) 6.9 (0.5) 0.013*
2004 12.5 (1.6) 11.6 (2.1) 14.0 (1.1) 14.1 (2.0) 0.211
Forbs Pre 20.7 (1.2) 20.2 (2.6) 19.5 (1.5) 18.8 (2.3) 0.510
2004 33.9 (1.5)a 38.1 (4.3)b 39.6 (1.9)b 43.7 (5.8)c 0.021*
Shrubs Pre 7.5 (0.6) 6.8 (1.0) 8.7 (1.1) 8.1 (1.1) 0.060
2004 8.8 (0.9) 7.9 (0.8) 10.2 (1.3) 8.5 (1.5) 0.162
Tree seedlings Pre 2.0 (0.1) 2.1 (0.3) 2.3 (0.2) 2.3 (0.4) 0.635
2004 2.1 (0.0) 2.2 (0.1) 2.4 (0.2) 2.3 (0.3) 0.920
*P < 0.05

Richness of graminoids, shrubs, and tree seedlings was unchanged by treatment. However, broad life form groups can disguise the response of individual species. Species that were strongly affected by treatments were identified using indicator species analysis [1] contrasting treatments within years. Burning treatments created microsites suitable for colonization by seed-dispersed species and increased vigor resulting in greater cover of many sprouting perennial species. Similarly, many species responded to cutting by spreading via rhizomes or stolons. The following table displays species with significant indicator values (P<0.05), their generalized individual responses to treatments, and the observed mechanism for response in this study.

Common name Latin name Treatment response Response mechanism
Burn-only Thin-only Thin-Burn
western yarrow Achillea millefolium None Increase Increase Seeds, rhizomes,
increased vigor
tickle grass Agrostis scabra None Increase Increase Seeds,
increased vigor
Holboell's rockcress Arabis holboellii None None Increase Seeds
kinnikinnick Arctostaphylos
None Increase None Stolons,
increased vigor
pinegrass Calamagrostis rubescens None Increase Increase Rhizomes, seeds, increased vigor
musk thistle Carduus nutans None None Increase Seeds
Ross' sedge Carex rossii None None Increase Seeds,
increased vigor
fireweed Chamerion angustifolium Increase None Increase Seeds
Canada thistle Cirsium arvense None None Increase Seeds, rhizomes
bull thistle Cirsium vulgare Increase Increase Increase Seeds,
increased vigor
miner's-lettuce Claytonia perfoliata None None Increase Seeds
blue-eyed Mary Collinsia parviflora Increase None Increase Seeds,
increased vigor
quill cryptantha Cryptantha affinis None None Increase Seeds
houndstongue Cynoglossum officinale None Increase Increase Seeds
mountain tansymustard Descurainia incana None None Increase Seeds
shooting star Dodecatheon pulchellum Increase Increase None Seeds,
increased vigor
tall annual willowherb Epilobium brachycarpum Increase Increase Increase Seeds
glaucus willowherb Epilobium glaberrimum None Increase Increase Seeds
spreading fleabane Erigeron divergens None None Increase Seeds
deceptive groundsmoke Gayophytum decipiens None None Increase Seeds
autumn dwarf gentian Gentianella amarella None Increase Increase Seeds
rattlesnake plantain Goodyera oblongifolia None Decrease Decrease Shade-adapted
houndstounge hawkweed Hieracium cynoglossoides None None Decrease Burn mortality
Rocky Mountain juniper Juniperus scopulorum None None Decrease Burn mortality
prairie Junegrass Koeleria macrantha None None Increase Seeds,
increased vigor
prickly lettuce Lactuca serriola Increase None Increase Seeds
western larch seedlings Larix occidentalis None None Increase Seeds
field cottonrose Logfia arvensis Increase Increase Increase Seeds
nodding microceris Microseris nutans Increase None None Seeds
narrowleaf minerslettuce Montia linearis None None Increase Seeds
Pacific ponderosa pine seedlings Pinus ponderosa var. ponderosa Decrease None Decrease Burn mortality
prostrate knotweed Polygonum aviculare None None Increase Seeds
selfheal Prunella vulgaris None None Increase Seeds
Wright's cudweed Pseudognaphalium canescens Increase None Increase Seeds
Rocky Mountain Douglas-fir seedlings Pseudotsuga menziesii var. glauca Decrease None Decrease Burn mortality
sheep sorrel Rumex acetosella None None Increase Seeds
wormleaf stonecrop Sedum stenopetalum None None Decrease Burn mortality
prairie goldenrod Solidago missouriensis None Increase None Rhizomes, seeds
Rocky Mountain goldenrod Solidago multiradiata Increase Increase Increase Rhizomes, seeds
common dandelion Taraxacum officinale None None Increase Seeds
yellow salsify Tragopogon dubius None Increase Increase Seeds
clover Trifolium spp. None None Increase Stolons, seeds
dwarf huckleberry Vaccinium caespitosum None Increase None Rhizomes
common mullein Verbascum thapsus Increase Increase Increase Seeds

Coniferous regeneration (<4.5 feet tall) was virtually eliminated from 0.00025-acre quadrats but was still present on 0.25-acre plots. Despite a significant reduction in seedling density at the small scale, regeneration maintained a broad-scale presence similar to that described historically (dispersed and patchy). Western larch regeneration increased significantly in the thin-burn treatment compared to the control, reflecting an adaptation for postfire establishment. Many locally rare, disturbance-adapted understory species also became more abundant after treatment, especially in the thin-burn. While abundance of most species was initially reduced by burning, 2 years after treatment abundance of most species in active treatments was equal or greater than that in the control. The following linked files provide cover and frequencies (by treatment) of all successfully identified species before treatment and in 2004 (2 years after burning and 3 years after harvest):



The thin-burn treatment resulted in conditions most similar to those described historically, with significantly reduced conifer sapling density and increased native understory richness and abundance of individual species. This treatment was also associated with the most negative aspect of restoration--nonnative species invasion [6].

The majority of understory species at this site were resilient to restoration treatments, especially when given several growing seasons to respond. Many native species that were locally rare prior to treatment benefited from active restoration treatments, especially the thin-burn. However, nonnative species responded similarly and may require specific management strategies to limit their establishment and spread following treatments intended to benefit natives.

Further monitoring will be necessary to determine long-term community trends. However, after 3 years of response, restoration treatments show promise for favoring disturbance-adapted native species, particularly locally rare and short-lived species that may have declined in ponderosa pine forests during a century of fire exclusion.

All active treatments successfully reduced some component of hazardous fuels: surface, crown, or both. Surface fuel accumulations were reduced in all size classes by the burn-only treatment. Although thinning increased fuel loads in the litter+1-hour, 10-hour, and 100-hour classes, burning following thinning (thin-burn treatment) reduced fuel loads below pretreatment levels in most classes. Pre- and immediate post-treatment fuel loadings are summarized below by treatment and size class.

Treatment Litter+1-hour (Tons/acre) 10-hour (Tons/acre) 100-hour (Tons/acre) 1000-hour (Tons/acre) Duff depth (inches)
Pre Post Pre Post Pre Post Pre Post Pre Post
Control 2.1 n.s.* 0.8 n.s.* 1 n.s.* 8.1 n.s.* 1.3 n.s.*
Burn-only 1 0.3 0.7 0.4 0.8 0.5 6.1 2 0.8 0.5
Thin-only 0.9 2.8 0.7 3.3 0.7 3.3 4.2 4.2 1 0.8
Thin-burn 0.9 0.4 0.7 0.9 0.7 2.1 3.8 2.6 1.1 0.7
*n.s. = not sampled

Crown fire hazard was modeled for all treatments using crowning index. Crowning index is defined as the windspeed needed to maintain a crown fire once fire has reached the main canopy. Lower crowning index values (e.g., <25 miles/hour) represent stand structures with relatively greater hazard, whereas higher values (e.g., >50 miles/hour) represent relatively low hazard. The least hazardous post-treatment conditions were achieved by the thin-burn treatment, though all active treatments reduced crown fire hazard. Thinning alone modestly increased crowning index, but when the thin-only treatment was followed by timber stand improvement (TSI) cutting of most saplings, crowning index increased substantially. However, should wildfire occur, potential mortality from crown scorch is elevated in the thin-only treatment due to increased loads of untreated surface fuels.

Crowning index (mph)
Control Burn-only Thin-only Thin-only with TSI Thin-burn
21 21 28 28 30
21 26 37 54 68

The Lubrecht FFS study provides evidence that alternative restoration treatments can modify potential fire behavior and differentially impact understory plant communities. Taken collectively, these results suggest that all active treatments promote a more open overstory and diverse understory community characteristics commonly associated with historically sustainable conditions. However, a mosaic of treatments (including untreated areas) would likely be needed to increase landscape-scale heterogeneity and improve longer-term sustainability of this ponderosa pine ecosystem.

This Research Project Summary is product #111 of the FFS study funded by the Joint Fire Sciences Program. For more information on the Lubrecht FFS study and links to products generated by this research, visit our website at

This Research Project Summary contains fire effects and/or fire response information on the following species. For further information, follow the highlighted links to the FEIS reviews for those species.


Common name Scientific name
Rocky Mountain juniper Juniperus scopulorum
western larch Larix occidentalis
Rocky Mountain lodgepole pine Pinus contorta var. latifolia
Pacific ponderosa pine Pinus ponderosa var. ponderosa
quaking aspen Populus tremuloides
Rocky Mountain Douglas-fir Pseudotsuga menziesii var. glauca
Scouler's willow Salix scouleriana
Rocky Mountain maple Acer glabrum
Saskatoon serviceberry Amelanchier alnifolia
kinnikinnick Arctostaphylos uva-ursi
mountain big sagebrush Artemisia tridentata ssp. vaseyana
Oregon-grape Berberis repens
snowbrush ceanothus Ceanothus velutinus
prince's-pine Chimaphila umbellata
green rabbitbrush Chrysothamnus viscidiflorus
Douglas hawthorn Crataegus douglasii
oceanspray Holodiscus discolor
common juniper Juniperus communis
menziesia Menziesia ferruginea
green-flowered wintergreen Pyrola chlorantha
whiteveined wintergreen Pyrola picta
sidebells wintergreen Pyrola secunda
wax current Ribes cereum
gooseberry currant Ribes montigenum
Wood's rose Rosa woodsii
thimbleberry Rubus parviflorus
russet buffaloberry Shepherdia canadensis
white spirea Spiraea betulifolia
common snowberry Symphoricarpos albus
dwarf huckleberry Vaccinium caespitosum
big huckleberry Vaccinium membranaceum
western needlegrass Achnatherum occidentale
Richardson needlegrass Achnatherum richardsonii
tickle grass Agrostis scabra
dense silkybent Apera interrupta
nodding brome Bromus anomalus
cheatgrass Bromus tectorum
purple pinegrass Calamagrostis purpurascens
pinegrass Calamagrostis rubescens
northwestern sedge Carex concinnoides
elk sedge Carex geyeri
smallwinged sedge Carex microptera
Nebraska sedge Carex nebrascensis
chamisso sedge Carex pachystachya
Ross' sedge Carex rossii
California oatgrass Danthonia californica
timber oatgrass Danthonia intermedia
onespike oatgrass Danthonia unispicata
slender hairgrass Deschampsia elongata
bottlebrush squirreltail Elymus elymoides
blue wildrye Elymus glaucus
rough fescue Festuca altaica
Idaho fescue Festuca idahoensis
western fescue Festuca occidentalis
foxtail barley Hordeum jubatum
Baltic rush Juncus balticus
prairie Junegrass Koeleria macrantha
field woodrush Luzula campestris
timothy Phleum pratense
Canada bluegrass Poa compressa
Wheeler bluegrass Poa nervosa
fowl bluegrass Poa palustris
Kentucky bluegrass Poa pratensis
Sandberg bluegrass Poa secunda
bluebunch wheatgrass Pseudoroegneria spicata
tall trisetum Trisetum canescens
spike trisetum Trisetum spicatum
sixweeks grass Vulpia octoflora
western yarrow Achillea millefolium
pale agoseris Agoseris glauca
annual agoseris Agoseris heterophylla
onion Allium spp.
Menzies' fiddleneck Amsinckia menziesii
pearly everlasting Anaphalis margaritacea
Pacific anemone Anemone multifida
pearly pussytoes Antennaria anaphaloides
raceme pussytoes Antennaria racemosa
pussytoes Antennaria spp.
spreading dogbane Apocynum androsaemifolium
Holboell's rockcress Arabis holboellii
rockcress Arabis spp.
ballhead sandwort Arenaria congesta
thymeleaf sandwort Arenaria serpyllifolia
foothill arnica Arnica fulgens
arnica Arnica spp.
Canadian milkvetch Astragalus canadensis
timber milkvetch Astragalus miser
arrowleaf balsamroot Balsamorhiza sagittata
Mariposa lily Calochortus spp.
small camas Camassia quamash
bluebell bellflower Campanula rotundifolia
musk thistle Carduus nutans
spotted knapweed Centaurea maculosa
big chickweed Cerastium fontanum
nodding chickweed Cerastium nutans
fireweed Chamerion angustifolium
lambsquarters Chenopodium album
blight goosefoot Chenopodium capitatum
narrowleaf goosefoot Chenopodium leptophyllum
sulphur Indian paintbrush Castilleja sulphurea
Canada thistle Cirsium arvense
bull thistle Cirsium vulgare
miner's-lettuce Claytonia perfoliata
blue virgin's bower Clematis occidentalis
blue-eyed Mary Collinsia parviflora
tiny trumpet Collomia linearis
Canadian horseweed Conyza canadensis
quill cryptantha Cryptantha affinis
houndstongue Cynoglossum officinale
mountain lady-slipper Cypripedium montanum
mountain tansymustard Descurainia incana
roughfruit fairybells Disporum trachycarpum
shooting star Dodecatheon pulchellum
tall annual willowherb Epilobium brachycarpum
glaucus willowherb Epilobium glaberrimum
cutleaf daisy Erigeron compositus
spreading fleabane Erigeron divergens
streamside fleabane Erigeron glabellus
shaggy fleabane Erigeron pumilus
prairie fleabane Erigeron strigosus
threenerve fleabane Erigeron subtrinervis
glacier lily Erythronium grandiflorum
showy aster Eurybia conspicua
subalpine aster Eurybia merita
woodland strawberry Fragaria vesca
Virginia strawberry Fragaria virginiana
yellow fritillary Fritillaria pudica
common gaillardia Gaillardia aristata
stickywilly Galium aparine
northern bedstraw Galium boreale
deceptive groundsmoke Gayophytum decipiens
autumn dwarf gentian Gentianella amarella
sticky purple geranium Geranium viscosissimum
old man's whiskers Geum triflorum
rattlesnake plantain Goodyera oblongifolia
curlycup gumweed Grindelia squarrosa
hairy false goldenaster Heterotheca villosa
roundleaf alumroot Heuchera cylindrica
white hawkweed Hieracium albiflorum
Canadian hawkweed Hieracium canadense
houndstongue hawkweed Hieracium cynoglossoides
narrowleaf hawkweed Hieracium umbellatum
prickly lettuce Lactuca serriola
blue lettuce Lactuca tatarica
northern linanthus Linanthus septentrionalis
twinflower Linnaea borealis
western stoneseed Lithospermum ruderale
field cottonrose Logfia arvensis
nineleaf biscuitroot Lomatium triternatum
silvery lupine Lupinus argenteus
small tarweed Madia exigua
false Solomon's-seal Maianthemum racemosum
narrowleaf cowwheat Melampyrum lineare
Alaska oniongrass Melica subulata
yellow sweetclover Melilotus officinalis
wild mint Mentha arvensis
nodding microceris Microseris nutans
narrowleaf minerslettuce Montia linearis
strict forget-me-not Myosotis stricta
thinleaved owl's clover Orthocarpus tenuifolius
sweetcicely Osmorhiza berteroi
woolly groundsel Packera cana
coiled lousewort Pedicularis contorta
Alberta beardtongue Penstemon albertinus
penstemon Penstemon spp.
silverleaf phacelia Phacelia hastata
slender phlox Phlox gracilis
slender-spire orchid Piperia unalascensis
common plantain Plantago major
prostrate knotweed Polygonum aviculare
Douglas' knotweed Polygonum douglasii
sticky cinquefoil Potentilla glandulosa
slender cinquefoil Potentilla gracilis
sulphur cinquefoil Potentilla recta
selfheal Prunella vulgaris
Wright's cudweed Pseudognaphalium canescens
woodland pinedrop Pterospora andromedea
sharpleaf buttercup Ranunculus acriformis
sheep sorrel Rumex acetosella
curly dock Rumex crispus
wormleaf stonecrop Sedum stenopetalum
lambstongue ragwort Senecio integerrimus
tall ragwort Senecio serra
Menzies' campion Silene menziesii
Oregon silene Silene oregana
prairie goldenrod Solidago missouriensis
Rocky Mountain goldenrod Solidago multiradiata
hooded ladies-tresses Spiranthes romanzoffiana
longstalk starwort Stellaria longipes
western aster Symphyotrichum ascendens
common dandelion Taraxacum officinale
western meadow-rue Thalictrum occidentale
arrow thelypody Thelypodium sagittatum
field pennycress Thlaspi arvense
yellow salsify Tragopogon dubius
clover Trifolium spp.
largeflower triteleia Triteleia grandiflora
stinging nettle Urtica dioica
woods valerian Valeriana dioica
common mullein Verbascum thapsus
thymeleaf speedwell Veronica serpyllifolia
hookspur violet Viola adunca
meadow deathcamas Zigadenus venenosus
brittle bladderfern Cystopteris fragilis


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