BOTANICAL SURVEY OF THE SCRATCHGRAVEL HILLS
LEWIS AND CLARK COUNTY, MONTANA

Prepared by:

Bonnie L. Heidel and Stephen V. Cooper

Montana Natural Heritage Program

1515 E.Sixtli Avenue

Helena, MT 59620-1800

Prepared for:

U.S.D.I. Bureau of Land Management

P.O. Box 3388

Butte, Montana 59702-3388

Agreement No. 1422E930A960015, Task Order No. 9
April 1998

(©) 1998 Montana Natural Heritage Program

This report should be cited as follows:

Heidel, B- L. and S. V. Cooper. 1998. Botanical Survey of the Scratchgravel Hills. Unpubhshed

report to the Bureau of Land Management. Montana Natural Heritage Program, Helena. 44
pp. + app.

SUMMARY

Systematic baseline survey was conducted in the Scratchgravel Hills, documenting two Montana plant
species of special concern, two watch species, and six plant associations. They represent a ibiological
crossroads! pattern, made up of the following noteworthy features:

An extensive population of lesser rushy milkvetch {Astragalus convallarius), a Great Basin plant
species disjunct at the northern end of its range

A small population of linearleaf fleabane (Erigeron linearis), a Columbia Plateau plant species
disjunct at the eastern end of its range

Two small populations of taxa that remain on the watch list because they live primarily or exclusively
in Montana and nowhere else, Klausibladderpod (Lesquerella klausii) and rabbitsfoot crazy weed
(Oxytropis lagopus var. conjugens)

Two relatively intact and well-developed Rocky Mountain plant associations that are noteworthy for
their site-specific conditions, though not for their plant association rarity; the Douglas fir/rough
fescue plant association (Pseudotsuga menziesii/Festuca scabrella p.a.), and the foothills form of
the bluebunch wheatgrass plant association (Pseudoroegneria spicatum fi Bouteloua gracilis p.a.)

One of these, the lesser rushy milkvetch occurrence, represents among the best examples in the state.
Two more of these represent the only documented examples in the Helena Valley and among the most
unusual examples in the state, including the linearleaf fleabane occurrence and the Douglas fir/rough
fescue plant association.

The Scratchgravel Hills have a moderate level of state biodiversity significance warranting elevated
attention to the most pressing management needs, noxious weed control.

ACKNOWLEDGEMENTS

The contributions of many people are reflected in this report. Cedron Jones (Montana Natural Heritage
Program) provided site information, data digitizing and GIS maps. Element occurrence data processing
was assisted by Katie Schletz (Montana Natural Heritage Program) and Cedron Jones. Scott Lee-
Chadde (Montana Natural Heritage Program) ran the ECADs stratification. Sarah Gage (University of
Washington Herbarium) provided verification of the Erigeron linearis specimen. Sally Sovey (Bureau
of Land Management) provided encouragement and coordination needed to turn a project idea into an
actuality. Tribute is paid to Jim Reichel, our extraordinary zoologist colleague in the Montana Natural
Heritage Program.

This study was funded as a challenge cost-share between the U.S.D.I Bureau of Land Management and
the Montana Natural Heritage Program.

TABLE OF CONTENTS

SUMMARY 3

ACKNOWLEDGEMENTS 4

INTRODUCTION 1

STUDYAREA 2

Geology 2

Soils 4

Climate 4

Flora 4

Vegetation 5

Wildlife 5

METHODS 5

Botanical methods 6

Ecological Methods 7

BOTANICAL RESULTS 10

Astragalus convallarius Greene van convallarius 12

Erigeron linearis (Hook.) Piper 18

Lesquerella klausii Rollins 24

Oxytropis lagopus Nutt. var. conjugens Bameby 28

ECOLOGICAL RESULTS 33

Vegetation Descriptions: WOODLAND TYPES 34

Vegetation Descriptions: SHRUBLAND TYPE 37

Vegetation Descriptions: GRASSLAND TYPES 38

DISCUSSION 40

LITERATURE CITED 42

FIGUPIES

Figure 1. Scratchgravel Hills study area 3

Figure 2. ECODATA plot locations in the Scratchgravel Hills 9

Figure 3. Sensitive plant locations in the Scratchgravel Hills 11

Figure 4. Astragalus convallarius illustration 13

Figure 5. Erigeron linearis illustration 18

Figure 6. Oxytropis lagopus var. conjugens illustration 30

TABLES

Table 1. Montana plant species of special concern in the Helena Valley area 6

Table 2. Plant associations of the Scratchgravel Hills study area 33

APPENDICES
Appendix A. Element Occurrences
Appendix B. Photo Documentation

Lesser rushy milkvetch {Astragalus convallarius)

Linearleaf fleabance {Erigeron linearis)

Klausi bladderpod {Lesquerella klausii)

Woodland opening habitat supporting Klausi bladderpod

Rabbitsfoot crazyweed {Oxytropis lagopus var. conjugens)

Bluebunch wheatgrass perimeter; looking south to Helena

Typical ponderosa pine/bluebunch wheatgrass plant association

Coring mature Douglas-fir in the Douglas-fir/rough fescue plant association

Bitterroot {Lewisia rediviva), a common plant in the Scratchgravel Hills
Appendix C. Preliminary flora of the Scratchgravel Hills
Appendix D. ECODATA analysis

INTRODUCTION

The Scratchgravel Hills are an island of public land administered by the Bureau of Land Management in
the Helena Valley. The Hills represent a prominent landmark, undeveloped open space, window into
local mining history, wildlife refugium, and a potentially biologically-unique landscape. For this latter
reason, baseline systematic inventory of the flora and vegetation was conducted to analyze its botanical
significance.

The only previous written record and review of its botanical resource values was presented in a
Scratchgravel Hills planning document (Scratchgravel Planning Committee and Lewis and Clark
Areawide Planning Organization 1 984), alluding to the presence of the rare species, lesser rushy
milkvetch {Astragalus convallarius) and characterizing the vegetation in general terms:

lExisting vegetation at lower elevations is grasses, herbs and scattered shrubs with occasional
juniper and ponderosa pine. Higher elevations and north facing slopes are dominated by pine/fir
forest with a bunchgrass or fescue understory. i

The source of the collection information to support the rare species report was unknown, and the report
of a fescue woodland understory was also undocumented in addition to being unusual for such an arid
setting. These potentially indicate botanical significance.

This same Valley is one of rapid conversion as one of the fast-growing rural areas in Lewis and Clark
County, a county which is projected to have the greatest population growth between now and the year
20 1 (Bureau of Business and Economic Research 1 998). Any work on determining the status of
sensitive species found in the Helena Valley hinges on investigation of relatively intact public lands in the
Valley

Primary objectives of this study were to systematically survey botanical biodiversity features with
emphasis on those with BLM status, providing a botanical baseline. Systematic surveys provide a
process of setting and refining conservation targets for the rarest species, and the rarest or most
outstanding examples of natural vegetation as plant associations.

For example, Helena National Forest lands have been surveyed for sensitive plant species in the Big
Belt and Elkhom Mountains (Poole and Heidel 1 993). Survey targets included three iendemici species,
that is, species found exclusively or primarily in Montana: Klausibladderpod (Lesquerella klausii),
limestone larkspur {Delphinium bicolor ssp. calcicola) and rabbitis-foot crazyweed (Oxytropis
lagopus var. conjugens). In the course of this study and subsequent studies, these three endemics
have been documented at more sites, with little or no threats, such that they are no longer being tracked
but have been moved to the watch list for species of limited distribution (Heidel 1 997). Despite recent
renewed investigations, other uncommon plant species collected in the Helena Valley before the tum-of-
the-century (Atriplex truncata, Cypripedium parviflorum, Senecio debilis) have not been seen since.

STUDYAREA

The Scratchgravel Hills are a prominent isolated series of hills in the Helena Valley, Lewis and Clark
County. They are situated about four miles north of Helena between the Sevenmile, Tenmile and Silver
creeks, and they span about 5,500 acres in 1 8 sections (Figure 1). They are a largely-unbroken block
of public land administered by the Bureau of Land Management (BLM), surrounded by private land.
The elongate study area extends east- west, encompassing the Scratchgravel Hills landmark at the
eastern end and contiguous rolling lands to the west. Mention of the iScratchgravel Hillsi in the
following geology narrative refers to the landmark, while in the rest of this report it refers to the entire
study area.

General motorized access to the study area is possible via Echo Lane, foot access or limited motorized
access is provided at two public access points established on Tumbleweed Drive and an entry opposite
Norris Road, and a roadway that adjoins its western margin also provides foot access.

Geology

The Scratchgravel Hills are composed of the intruding Cretaceous granodiorite satellite pluton of the
Boulder Batholith, flanked by metasedimentary rocks of the Belt Supergroup, sedimentary rock, and
alluvium (Herrin et al. 1 987). The highest hills that represent the Scratchgravel Hills landmark are
derived from igneous batholith, weathering into very coarse sand, which with its associated mining
activity gave the hills the iscratchgraveli name. To the immediate north and west of the highest hills are
intruded Tertiary volcanics and metasedimentary rock. Farther west, the Helena Limestone sedimentary
formation, including dolomitic and argillaceous materials, covers the western half of the study area. In
addition. Quaternary alluvium is at the eastern perimeter (Herin et al. 1 987, Ross et al. 1 955, Lorenz
and Sweason 1951).

The ore bodies in the Scratchgravel Hills are contact-metamorphic deposits and veins, with at least 32
mines at the perimeter of the batholith stock (Scratchgravel Hills Planning Committee and Lewis and
Clark Areawide Planning Organization 1 984) . Except in the period of 191 4- 1918 when the Franklin
and Scratch Gravel Gold mines were actively producing gold and silver, mining has been sporadic and
intermittent. There are reports of historic placer mining predating surface excavations. Most of the
historic mining was in adits, but there is at least one open pit mine site, which remains active. The Hills
contain both patented and unpatented mining claims, and many claims were filed in periods when
precious mineral prices were up. For example, there were about 112 unpatented mining claims filed
between 1 979- 1981 (Scratchgravel Hills Planning Committee and Lewis and Clark Areawide Planning
Organization 1984).

Figure 1 . Scratchgravel Hills study area

Montana Natural Heritage Program, February 05, 1998

Soils

Soils in the Scratchgravel Hills are highly erodible and several are very shallow, with extensive rock
outcrops in the hills (Bingham et al. 1 977). Their soil textures are classified as sandy loams and
channery loams but gravel makes up a major portion of the ground surface over much of the study area.
Despite their loamy textures, profiles are not well-developed, and frost fractures are commonplace early
in the season.

The soils on the highest hills, derived from granodiorite, are mainly Woodgulch-Rock Outcrop complex,
8-35% slope, a loamy sand (Binghan et al. 1 977). The soils derived from sedimentary rock in the
western end are Whitecow-Roto-Pensore channery loam , 4-35%. They are surrounded mainly by
Hauz-Tolman channery loams, 8-45%o; Roto-Pensore-Crago channery loams, 15-45%) and Crittenden
sandy loam, very rock, 4-3 5%o slope.

Climate

The Helena Valley climate is represented by meteorological data compiled at the Helena Airport (U.S.
Dept. Commerce 1 982). Median monthly temperatures range from 1 8.9J F (-7.3 j C) in January to
69.3 j F (20.7J C) in July. Annual average (median) precipitation is 1 1 . 14 inches (27.8 cm). This is
consistent with the Helena Valley being among the northernmost of Montanais arid intermontane valleys.

The Hills are an exposed island within the Valley, having microclimate extremes that are exaggerated by
the steepness of slopes, heightened exposure to sun and wind, and some soils that are porous
(droughty).

Flora

The flora of the general Helena Valley was relatively well-documented in early years because Helena
was a major center of growth in the new territory and state; home and hub for botanists and their formal
or informal studies and projects. Projects included efforts to display the state flora, represented by sets
of specimens that included a Helena-area collection, in the 1 892 Worldis Fair. Subsequent collections of
the local flora have been sporadic, and only in recent years have their been efforts to conduct systematic
baseline inventories (e.g., Poole and Heidel 1 993), collect a representative set of specimens for
reference, and compile local floristic lists.

The Hills in particular have been anecdotally noted as among the best places around the Capital to see
the state flower, bitterroot (Lewisia rediviva), but there was not information on the rest of the local
flora.

Vegetation

The Hills are conspicuous from Helena and the surrounding valley as dark promontories with a cover of
conifers compared to the light hues of the open plains that surround them. It has been inferred that all
timber within proximity of the Helena mining camp and boom-town was extensively logged (Phillips
1 997), so that any current stands represent post-settlement regeneration. There have not been stand
exams or other vegetation studies in the Hills to characterize the conifer communities or grassland
resources.

Wooded lands make up app. 45% of the study area (based on timber cover mapped onto the USGS
topographic maps); and grassland makes up virtually all of the remainder. Surface water is absent in the
Hills except early in the season along ephemeral watercourses, including a few small springs and seeps,
or adjoining rangeland developments (stock tanks). Soils throughout most of the area are very porous,
even along the watercourses, so that riparian community development is scant and restricted to narrow
bands or more commonly wanting.

The Hills were historically used as rangeland, but have not been grazed since the 1 980is.

Wildlife

One of the earliest recorded names given the Helena Valley is ITonahi, which refers to a rich hunting
ground in the Blackfeet language. Repeated bison use was reported, with high numbers. The current
mammal and bird fauna of the Scratchgravel Hills is listed in the current planning document
(Scratchgravel Planning Committee and Lewis and Clark Areawide Planning Organization 1 984). This
same document notes its significance in providing critical fawning areas for pronghom antelope as well
as supporting small resident populations of pronghom antelope, mule deer, and whitetail deer.

METHODS

Methods were designed to address botanical and ecological features in a systematic baseline survey
approach, identifying all priority species and community diversity features within the landscape. The
study was not exhaustive in screening every quarter/quarter section but provides a framework identifying
the priority features, evaluating their significance, and enumerating potential management questions and
concems.

Dual-purpose botanical and community surveys were conducted by the principal author throughout the
growing season (June 1 , 20-2 1 , 24, and 29; July 22 and 31); and by both authors on September 24.

Botanical methods

Prior to fieldwork, the Biological Conservation Database maintained by the MTNHP was queried for
occurrences of Montana plant species of special concern (Heidel 1997) and any watch species known
from the vicinity of the study area. There are element occurrence records of six species within app. a
Smile radius (Table 1 ). One of the species, lesser rushy milkvetch (Astragalus convallarius) , is
known from multiple records in the area, and has also been reported and observed in the area in the
past (document (Scratchgravel Planning Committee and Lewis and Clark Areawide Planning
Organization. 1984; Cooper et al. pers. obs.). Three of the species are on the state watch list as species
that are no longer being tracked but which are of limited distribution and biodiversity significance.
Fieldwork priority was placed on BLM sensitive and watch species (USDI ELM 1 996), but all species
recognized as Montana plant species of special concern or as watch species (Heidel 1 997a) were
considered.

Table 1. Montana plant species of special concern in the Helena Valley area.

COMMENTS

Reported from the study area;

collected elsewhere in Helena area

Collected in 1 899 in Helena area

SPECIES

RANK

BLM STAT.

Astragalus

G5S2

Watch

convallarius

(Lesser Rushy

Milkvetch)

Atriplex truncata

G5SH

Watch

(Wedge-leaved

saltbush)

Cypripedium

G5 S2S3

Watch

parviflorum (Yellow

ladyis-slipper)

Lesquerella klausii

G3S3

Watch

(Klausi bladderpod)

Watch

Oxytropis lagopus

G4T3 S3

-

var. conjugens

Watch

(Rabbitsfoot

crazyweed)

Senecio debilis

G3G4 S3

Watch

(Rocky Mountain

Watch

ragwort)

Collected in 1 89 1 in Helena area

Remains a state watch species as a

state endemic; collected in Big

BeltMts.

Remains a state watch species as a

regional endemic; collected in

Helena area

Remains a state watch species as a
regional endemic; collected in
1 898 around County Fairgrounds

The habitats and phenology of these six species were considered in fieldwork planning. The timing of
fieldwork focused around the phenology of the primary target species, lesser rushy milkvetch
{Astragalus convallarius), because it was already reported from the area. In years with sufficient
moisture, such as 1 997, it can be identified any time in the growing season during or after flowering in
mid June. The habitat of lesser rushy milkvetch has been characterized as grasslands and open
woodlands, a broad habitat description that fits most of the Scratchgravel Hills landscape. The

phenology and habitats of the rest of the target species span the entire growing season and represent an
array of habitats from wetland to upland outcrop settings, placing a premium on multiple visits through
the course of the summer and over the range of study area habitats.

For each sensitive species encountered, a Species of Special Concern survey form was filled out,
accompanied by photographic documentation, and a voucher specimen when collecting did not
significantly impact the population (Montana Native Plant Society 1 993). All voucher specimens will be
deposited at the University of Montana (MONTU), with duplicate material deposited in Montana State
University (MONT).

The routine sensitive species survey steps in conducting site-specific project reviews can be summarized
as follow:

1 . Check existing records for sensitive plant information in and around the proj ect area.

2 . Set species search targets and timeframe(s) for fieldwork accordingly.

3 . Survey the appropriate habitat(s) at the appropriate time(s) of the growing season.

4 . Collect information on any sensitive plant populations, and document them by photos
and specimens.

These routine sensitive species survey steps were augmented to meet the baseline objectives with the
addition of the following steps:

1 . Maintain a running list of species observed and collected to produce a preliminary study area fiora,

2 . Deliberately span the geographic extent of the area, traversing the range of elevations, substrates,
and apparent habitats, and

3 . Make repeat visits over the course of the growing season.

Ecological Methods

Systematic survey was planned to include the extent of BLM-administered land, the full range of
topographic positions, the range of substrates as represented by bedrock geology (Ross et al. 1 955),
and the observed array of habitat types. The U.S.G.S. topographic maps (Scratchgravel Hills 7.5i,
Austin 7.5i) were carried into the field as an aid in determining routes, in traversing the range of
topographic positions, and in selecting and mapping vegetation sample sites.

There were no site-specific vegetation references to compile in preparing for the fieldwork. General
vegetation classification references for western Montana provide the frame of reference for
characterizing timbered habitat types, grassland and steppe habitat types and riparian or wetland habitat
types. The compilation of documented vegetation units for Montana is represented in the plant
association classification by Bourgeron and Engelking (1 994), where iplant association! is defined as
representing existing natural vegetation units encompassing both the habitat type units as climax and

community type units as serai. Throughout this report, we will use the plant association (p.a.) term in
reference to any naturally-occurring vegetation unit without regard to successional status.

Vegetation and site characteristics were documented for 2 1 circular 1/10 acre plots according to
methodology described in Cooper (1 995). Standard MTNHP community survey forms were used to
record plot data including location, environmental features (elevation, slope, landscape position,
substrate, and ground cover) and ocular canopy cover estimates (Daubenmire 1 959) for all vascular
plant species. The distribution of vegetation study plots is shown in Figure 2.

The vegetation data set was analyzed using the STRATA program of E.C.A.D.S. (Ecological
Classification and Description System), a USDA Forest Service ecological sampling package designed
to stratify the data sets in keeping with habitat type classification concepts (Daubenmire 1 959).

Note: All taxonomic nomenclature follows Dom (1 984) unless otherwise stated. The most notable
exceptions are made for the wheatgrasses using the nomenclature of Kartesz (1 994) for consistency
with the regional classification (Bourgeron and Engelking 1 984), and for which synonomy with other
widely used scientific names is provided.

Soils data were not collected, and the soils mapping reference (Bingham et al. 1 977) as a preliminary
work did not distinguish the likely soil differences accompanying plant associations that occupied small
areas.

Figi

jre2.

ECODATA plot locations in the Scratchgravel Hills

^r^^fix-

1 i^pi^p:|| ||j ^^

■'""/;'' ',::i;i

MS

m

/^^=^^^^ Helena

^^

^/^ *

Montana Natural Heritage Program, February 05, 1998

BOTANICAL RESULTS

Two Montana plant species of special concern and two watch species were documented in the study
area (Figure 3), including:

One of the four largest known populations of lesser rushy milkvetch {Astragalus

convallarius) in the state,

A small, highly disjunct population of linearleaf fleabane (Erigeron linearis) representing

the easternmost and possibly the ibesti occurrence in the state, and
- Very small populations of the two watch species, Klausi bladderpod
(Lesquerella klausii) and rabbitfoot crazy weed (Oxytropis lagopus var.
conjugens). Note: A voucher specimen of the first species is still needed. It
was collected after all of its fruits had dehisced. While the common species of
Lesquerella can be ruled out, determination of the specimens as L klausii
cannot be considered as certain.

Only 1 82 plant species were documented in compiling the preliminary Scratchgravel Hills flora
(Appendix C.) This is relatively low in total species numbers, but is to be expected considering the near-
absence of wetland habitat. It may also reflect the incompleteness of the documentation. This flora,
while low in numbers, still presents an interesting combination of Great Plains and Rocky Mountain
species.

The status and site conditions for each of the four rare species are highlighted in the following narrative
by species.

10

Figure 3. Sensitive plant locations in the Scratchgravel Hills

Astragalus convallarius
JJ Erigeron linearis
v2J Lesquerella klausii
v3) Oxytropis lagopus var conjugens

Montana Natural Heritage Program, February 05, 1998

Astragalus convallarius Greene van convallarius

Lesser rushy milkvetch
Fabaceae (Bean Family)

STATUS

USFWS status: None
BLM status: Watch
USFS Region 1 status: None
Global rank: G5T5
State rank: S2

DESCRIPTION

General Description: Lesser rushy milkvetch is a slender herbaceous perennial with usually 1 -6 erect
to spreading stems, rising up to 5 dm high from a branching, underground rootcrown (Figure 4). The
compound or simple leaves are 2-1 1 cm long with 0-5 pairs of thread-like leaflets. Upper leaves are
usually simple, giving them a grass-like appearance. Foliage is sparsely hairy to glabrous in the upper
portion. Off-white or yellowish, pea-like flowers are sparsely scattered on stalks which are 2-14 cm
long and arise from the axils of the upper leaves. The upper petal of each flower is 7- 1 1 mm long and
bent upward. The calyx is 4-6 mm long and sparsely covered with white or black hairs. Pendent, green
or purple-mottled fruits are linear, flattened, 13-50 mm long, and 2-4 mm wide.

Flowering takes place in late June; prolonged to early August in years with ample soil moisture. Fruiting
is in July through August.

Diagnostic Characteristics: A. CONVALLARIUS is the only milkvetch in the Helena Valley with
both grass-like leaves and pendent, linear fruits. The closely-related ASTRAGALUS
DI VERSIFOLIUS is not known from Montana. The variety ASTRAGALUS CONVALLARIUS
VAR. CONVALLAERIUS is the only variety in Montana.

GEOGRAPHIC DISTRIBUTION

Rangewide Distribution: Southeastern Idaho to southwestern Montana, south to Wyoming and Utah.
Peripheral.

12

Figure 4

Illustration by Jeanne R. Janish

From 'Vascular Plants of the Pacific Northwest'

Astragalus convallarius
Lesser rushy milkvetch

Astragalus convallahus var. convallarius
Lesser rushy milkvetch

State Distribution: Eight
Montana occurrences are on
record from southwestern
counties that include
Beaverhead, Broadwater, and
Lewis and Clark counties.
One new record documented
by Peter Lesica in the
Centennial Valley is being
processed. Two more
occurrences have been
documented by Westech
researchers in 1997 and are
being submitted, including a
large occurrence in the
Limestone Hills on or
adjoining BLM lands, and
another occurrence in the Fort Harrison Military Reservation immediately south of the study area (Ken
Scow pers. commun.). All eleven records for the species in Montana are either in the Helena Valley
vicinity, where it is disjunct at the northern end of its distribution, or in the Centennial Valley; with no
known records in between.

Montana Natural Heritage Program

Historical Distribution: It was first collected in Montana near Helena in 1 891 by F. D. Kelsey. The
precise Helena area location was not specified with this collection or with a later Blankinship collection
made in the Helena area in 1 909. These historical collections are merged with more recent collection
records into the single large occurrence that is sporadic across much of the Helena South Hills.

Study Area Distribution: Astragalus convallarius occurs in the western half of the study area, in
patches and bands that cover several sections while covering only a limited total area (Figure 3). It tends
to be most consistently present at the margins of woodlands and in openings; found to a lesser extent in
some areas of open woodland, above watercourses where there is at least scattered tree cover, and
sometimes in restricted zones below forested slopes.

Environment: The ecological amplitude of the species is broad, but the speciesi distribution pattern is
often localized and uncommon. It occurs in both woodlands and grasslands in the foothills of the Helena
Valley at 3,880-5,200 ft. elevation. It is in grassland settings of the Centennial Valley at 8, 1 00 ft.
elevation. It is in a wide range of topographic positions of varying moisture content. It is most common
on well-drained slopes but can also be found in swale microhabitats.

Soils: Rangewide the species grows on most soil textures including sandy, loamy or clayey soils of
various origin and composition, most frequently on sedimentary formation (Bameby 1 964). In the
Helena Valley it usually grows on loamy soil derived from calcareous sedimentary parent material. Its
restriction to the western half of the study area may correspond with the extent of sedimentary parent
material.

14

Vegetation: Despite its limited distribution in Montana, it is found in a wide range of woodland,
shmbland and grassland plant associations, sometimes in multiple associations at one site. An extreme
example of local ecological amplitude is found in an occurrence above Winston (EO#004), where it has
been documented on vegetation transects in the following habitat types (Scow et al. 1 986):

1 . Elymus spicatus-Bouteloua gracilis p. a.,

2. Elymus spicatus-Poa secunda p. a.,

3. Festuca idahonis-Elymus spicatus p. a., and

4. Festuca scabrella-Elymus spicatus p. a.;

Note: It has locally highest canopy cover, frequency and constancy in the last of these plant associations,
which is also the most mesic.

In the Limestone Hills, it extends into arid plant associations on the toeslopes of the limestone outcrops
in Artemisia nova and Festuca idahoensis plant associations as well as in associations dominated by
Juniperus scopulorum or hy Aremisia tridentata (Ken Scowpers. commun.).

In the Scratchgravel Hills study area it occupies mainly wooded habitat and ecotones, and discrete
areas of grassland and steppe. It is found in segments of the Pinus ponderosa/Pseudoroegneria
spicata plant association, plus the localized Artemisia tridentata/Pseudoroegneria spicata plant
association, and restricted related phases (Pinus ponderosa/Arctostaphylos uva-ursi/
Pseodoroegneria spicata; Pseudoroegneria spicata-Gutierrezia sarothrae). Immediately west of
the study area, an outlying cluster of plants occurs in a subpopulation found on alluvium along an
ephemeral watercourse within a landscape dominated by Pseudoroegnera spicata - Bouteloua
gracilis p.a. Immediately south of the study site it occupied swale microsites, possibly an association of
Pascopyrum smithii-Nessula viridula with a high component of Poapratensis, within open plains
dominated by Pseudoregneria spicatum-Bouteloua gracilis (Ken Scow pers. comm.). A composite
list of associated species in the Scratchgravel Hills includes:

Achillea millefolium

Antennaria (mic)

Antennaria parvi

Arenaria congesta

Arnica soraria

Artemisia campestris

Artemisia frigida

Artemisia tridentata ssp. vaseyana

Bouteloua gracilis

Chrysopsis villosa

15

Commandra umbellatum
Crepis intermedia
Dodecatheonpungens
Douglasia montana
Erigeron compositus
Festuca idahoensis
Festuca scabrella
Gaillarida aristata
Gutierrezia sarothrae
Hymenoxys richardsonii
Lepidium densiflorum
Lewisia rediviva
Linum lewisii
Lomatium triternatum
Oryzopsis hymenoides
Penstemon procerus
Phlox bryoides
Pinus ponderosa
Pseodoroegneria spicata
Senecio canus
Stipa comata
Zigadenus venosus

SPECIES BIOLOGY

Life history: The longevity of this perennial species is not known.

Reproduction: It is assumed to be reproducing sexually by insect pollination.

Dispersal: Although the pod probably splits rapidly from tip to base, the force of the release is seldom
so violent as to eject the seeds any great distance (Bameby 1 964). The fact that the species has almost
no cluster pattern of distribution, and has a sporadic distribution in a variety of habitats suggests that it
has some as yet unidentified dispersal agent if not habitat specificity.

Biological interactions: No signs of browsing or predation were found. The species has a highly
reduced, drought-tolerant growth form indicating that it is not likely to be good competitor. But it is
perhaps more stress-tolerant than many of its associated montane species, maintaining growth and
reproductive activity longer in the growing season.

16

POPULATION BIOLOGY

Population size and condition: This species is easily overlooked, and population size estimates are
provided for only a couple of the occurrences in the state, ranging from app. 1 plants to over 5000
plants as estimated for the study area. In the Scratchgravel Hills it may be connected with
subpopulations on the Fort Harrison Military Reservation. In the upcoming second year of a two-year
study it will be possible to delimit speciesi distribution and consider this possibility (Scow pers.
commun.).

Population structure: It was frequently found in sporadic distribution at low densities. It was
occasionally found to be common or occasional in small openings. It has been noted in one place
outside the study area to be locally abundant along a highly ephemeral watercourse on droughty soils
under particular grazing regimes.

ASSESSMENT AND MANAGEMENT RECOMMENDATIONS

Threats to currently known populations: Land use conversions from rangeland to building sites or
cropland are immediate threats to the species on private property. The widespread indirect threat
throughout the Helena Valley is invasion of noxious weeds like spotted knapweed {Centaurea
maculata) and Dalmatian toadflax {Linaria dalmatica), and potentially as serious invasions by leafy
spurge {Euphorbia esula), diffuse knapweed {Centaurea diffusa), and Russian knapweed
{Centaurea repens).

Management practices and response: Limited information is available, though some of the highest
speciesi densities have been noted west of the study area on pasture that is part of a rotation grazing
system and which is heavily grazed in the winter or else early in the growing season. Note: At this site of
high density, it is restricted to a very well-drained ephemeral small water course. It has also been noted
at an old homestead site under heavy grazing on the Fort Harrison Reservation (Ken Scow pers.
commun.).

Recommendations for maintaining viable populations: Vigilant weed treatment at the three largest
occurrences on public land (Scratchgravel Hills, Limestone Hills and Mount Helena) is needed to
maintain viable populations in Montana. It is not known whether the fourth large site, the Chatham site,
has been converted to mining use since its local vegetation was documented.

Recommendations for further assessment: The breadth of habitat would suggest that it is not
imperiled unless there is landscape-wide loss of habitat, or unless the habitats collectively are threatened
or degenerating from weed invasion or alteration in the absence of natural processes. It is recommended
that it be retained as a BLM watch species and a Montana plant species of special concern unless there
are more occurrences including large ones outside the Helena Valley with no known threats. In any case,
this species is one of biogeographic significance as a disjunct.

17

Erigeron linearis (Hook.) Piper

(Linearleaf Fleabane; or Desert Yellow Daisy)
Family: ASTERACEAE

STATUS

USFWS status: None

BLM status: None

USFS Region 1 status: Sensitive

Global rank: G5

State rank: SI

DESCRIPTION

General Description: Linearleaf Fleabane is a perennial herb with unbranched stems that are 5-30
cm tall and which arise from a stout taproot and branched rootcrown (Figure 5). The mostly basal
leaves are linear and 1 -9 cm long. The bases of the stems and leaves are enlarged and straw-colored or
purplish, and the herbage is covered with fine gray hairs. The flower heads are usually solitary at the
ends of the stems. The involucral bracts are 4-7 mm long and are covered with long, appressed hairs
and occasionally also with glands. The 1 5-45 yellow rays are 4-11 mm long and the yellow disk flowers
are 3-5 mm long. There are 1 0-20 pappus bristles at the top of each achene.

Flowering in May-early June.

Diagnostic Characteristics: The Scratchgravel Hills plants had consistently short rays (4 mm) unlike
the conspicuous rays of the Beaverhead County population shown in Appendix B. Superficially, the
Scratchgravel Hill material resembled the HAPLOPAPPUS genus. However, the species and the
ERIGERON genus have taproots, narrow involucral bracts in one series, and the very short style
appendages less than 0.5 mm long. This is the only ERIGERON in our area with yellow rays.

DISTRIBUTION

Rangewide distribution: Southern B.C., south through e. WA and OR to n. NV and Yosemite
National Park, east through central ID to Yellowstone National Park and adjacent MT Peripheral.

18

Figure 5

Illustration by Jeanne R. Janlsh

From 'Vascular Plants of the Pacific Northwest'

Erigeron linearis
Linearleaf Fleabane

Erigeron linearis
Llnearleaffleabane

Montana Natural Hentage Program

State Distribution:

Bitterrootand
Pioneer mtns., and
Scratchgravel Hills

Montana counties:

Beaverhead, Lewis
and Clark, and
Ravalli cos.

Historical
distribution: Not
applicable. This
species was first
found in Montana in
1960.

Study area distribution: It is located in the eastern half of the study area, at two points on either side
of the highest hill (Figure 3). This represents the first time that it has been documented in Lewis and
Clark County, a disjunct eastward range extension.

HABITAT

Environment: Dry, often rocky soil from the plains and foothills to moderate elevations in the

mountains, often among sagebrush. Elev. 3900-6020 ft.

The settings for the two subpopulations in the Scratchgravel Hills differ markedly. The eastern
subpopulation is on 30 degree east-facing midslope setting where there is a steep opening on the
timbered hillside. The western subpopulation is on a gentle 5 degree bald lower slope with a southwest
aspect in open rolling plains.

Soils: The parent materials are unknown.

Vegetation: The plant associations in which it has been documented to date include dominance or co-
dominance by bluebunch wheatgrass (Pseudoroegneria spicata), often with mountain big sagebrush
{Artemisia tridentata ssp. vaseyana) directly associated with or surrounding the speciesi setting.

20

It is in two different plant associations in the Scratchgravel Hills sites, and associated species are
recorded separately for the two:

Festuca idahoensis n Pseodoroegneria spicata p.a. (eastern subpopulation)

Achillea millefolium

Antennaria spp.

Astragalus flexuosus

Chrysopsis villosa

Crepis acuminata

Cymopteris acaulis

Douglasia montana

Festuca idahoensis

Haplopappus acaulis

Lomatium triternatum

Pseudotsuga menziesii

Sedum lanceolatum

Selaginella densa

Woodsia scopulina

Pseodoroegneria spicata n fBouteloua gracilis) p.a. (western subpopulation)

Artemisia frigida

Artemisia tridentata ssp. vaseyena

Chrysopsis villosa

Commandra umbellata

Erigeron compositus

Gutierrezia sarothrae

Koeleria macrantha

Lewisia rediviva

Opuntia polyacantha

Plantago patagonica

Pseudoroegneria spicata

SPECIES BIOLOGY

Life history: The longevity of this perennial species is not known.

Reproduction: It is assumed to be reproducing sexually by insect pollination.

Dispersal: The fine pappus attached to each seed aids in wind dispersal.

Biological interactions: This species seems to occupy balds and local extremes in sparse vegetation
cover. This may indicate that it is a poor competitor or has germination requirements for bare soil.

21

Seed predation appears to be high. In examining flower structure under a compound microscope of the
3-5 plant specimens collected per subpopulation, it was observed that grubs had consumed the majority
of seeds on many flower heads.

POPULATION BIOLOGY

Population size and condition: Information collected to date indicates that the two subpopulations are
small, with an estimated total of 200 individuals. Plants are vigorously multi-stemmed, but significantly
shorter in stature (10-15 cm) compared to the Ermont Gulch population. Considering the fact that the
species was not located until the end of flowering, and it is not readily discerned after flowering, the
population information is to be treated as preliminary.

Population structure: Size class differences that might reflect age class differences were not noted.

ASSESSMENT AND MANAGEMENT RECOMMENDATIONS

Threats to currently known populations: The western subpopulation is close to a private mining
inholding that is active or has recently been active but does not directly affect it. There are also nearby
claims and exploratory pits on the BLM land. This same subpopulation lies directly above the head of a
watercourse in which leafy spurge is abundant in a continuous band at the bottom of the entrenched
channel, expanding upstream. Spotted knapweed is in a few patches along the watercourse, and is
more abundant in the mining area. Encroachment of the uplands from the watercourse and the mining
area has been limited to date.

The eastern subpopulation does not have immediate threats, in that mining activity and accompanying
spotted knapweed invasion are at greater distances.

Management practices and response: Unknown.

Recommendations for maintaining viable populations: Leafy spurge control in Section 28 is
critical. As the best documented occurrence records in the state, even though it is small, maintenance of
the Scratchgravel Hills population may be critical to the speciesi conservation.

Recommendations for further assessment: The known subpopulations appear to be small in plant
numbers and extent, but were found in mid June at the end of flowering activity. Survey during early
June is recommended for any project reviews on potentially suitable habitat in the eastern half of the
study area.

22

At least three of the four occurrences in the state are in landscapes with a history of intense mining
history. The question was raised whether the Ermont Gulch occurrence represents a population in its
natural habitat or an accidental introduction where mining machinery or a spot treatment with e.g., fire,
removed sagebrush cover (Heidel and Vanderhorst 1 996). The Scratchgravel Hills subpopulations
occur within undisturbed vegetation but seem unusually localized, and they do not prove or refute the
question about the nature of the species presence in Montana that has been raised.

BLM watch status designation is appropriate for this species, considering that BLM lands are the only
public lands where this species occurs in the state, while further assessment and noxious weed control
are underway.

23

Note: A voucher specimen of this species is still needed. It was collected after all of its fruits had
dehisced. While the common species ofLesquerella can be ruled out, determination of the
specimens as L. klausii cannot be considered as certain.

Lesquerella klausii Rollins

(Klausi Bladderpod)
Family: BRASSICACEAE

STATUS

USFWS status: None

BLM status: Watch

USPS Region 1 status: It was on the watch hst but dropped in 1 99 1 .

Global rank: G3

State rank: S3

DESCRIPTION

General Description: Klausi Bladderpod is a short-lived, perennial herb with a rosette of basal leaves
from a taproot and unbranched rootcrown, and stems that are erect or lie flattened on the ground
curving up at the tip, 6-1 5 cm high (Figure 6). Leaves are broadly spoon-shaped, 1 5-25 mm long,
entire-margined, and have long petioles; stem leaves are spatula-shaped and 6-9 mm long; herbage is
densely covered with branched, star-like hairs. The yellow flowers are borne on curved S-shaped
pedicels in a simple, loose inflorescence, 1 0-30 mm long; the 4 petals are ca. 6-8 mm long. The
broadly heart-shaped fruits are 5mm wide, 4 mm high, compressed contrary to the suture, and densely
hairy (adapted from Shelly 1988, Rollins 1995).

Flowering in May - June, fruiting in June - early July, depending on elevation.

Diagnostic characteristics: This species resembles PHYSARJAGEYERJ; however, the latter has
more deeply notched fruits and appears to be conflned to the southwestern part of the state. Its range
overlaps with LESQUERELLA ALPINA; the latter has narrow leaves (< 5 mm) that are the same at
the base and on the stem, and fruits which are narrowed and flattened at the tip.

DISTRIBUTION

Rangewide distribution: Western MT. State endemic.

State distribution: Centered in the Big Belt Mountains and westward to the south end of Rocky
Mountain Front.

Montana counties: Broadwater, Lewis and Clark, and Meagher Cos.

24

Historical distribution: Not applicable. This species was first discovered in 1 977 by Klaus
Lackschewitz.

Study area distribution: Only found in one location on the highest summit (Figure x).

HABITAT

Environment: Exposed, open, often south-facing slopes usually in montane settings. Elev. 4000-7700
ft. The Scratchgravel Hills occurrence was on 40% southwest-facing slope, in an upper slope position,
and below the highest point in the Hills.

Soils: It is characteristic of shale barrens and platy shale rubble, but is also found on limestone, argillite,
and quartz-derived substrates. The latter is consistent with its occurrence in the Scratchgravel Hills,
where it appears to be restricted to one opening and substrate of limited extent.

Vegetation: Its shale barrens habitat lies within ponderosa pine (Pinus ponderosa) or Douglas-fir
(Pseudotsuga menziesn) plant associations, also extending into higher elevation associations of limber
pine {Pinus flexilis) and Engelman spruce (Abies lasiocarpa). The local bunchgrass dominants often
include bluebunch wheatgrass () and sometimes Idaho fescue (Festuca idahoensis).

The Scratchgravel Hills occurrence follows the pattern in having local bluebunch wheatgrass dominance,
surrounded by both Douglas-fir and ponderosa pine. : A large number of associated species have been
documented among all of its occurrences (Poole and Heidel 1993). The species directly associated with
it on-site include:

Artemisia frigida
Aster alpigenus
Chrysopsis villosa
Oxytropis sericea
Penstmon nitidus
Pinus ponderosa
Pseudoroegneria spicata
Pseudotsuga menziesii
Senecio canus

SPECIES BIOLOGY

Life history: It is a short-lived perennial. Demographic monitoring of another endemic, Lesquerella
carinata var. languida (^summarized in Vanderhorst 1 995), provides a tentative framework for
understanding recruitment and mortality, and the resulting patterns of boom and bust cycles.

25

Reproduction: Lesquerella klausii is probably cross-pollinated by insects, as are most species in the
genus (Rollins and Shaw 1 973). Although self-incompatibility is common in Lesquerella, it is present in
at least some species. No evidence of vegetative reproduction has been observed.

Dispersal: The fruits oi Lesquerella klausii are papery and dry, and the seed is wingless. Probably
most seeds fall near the parent plants, and might be dispersed with the aid of wind and gravity. It is
likely to have a seedbank, like many short-lived perennials. High seed germination levels have been
noted in the two years following wildfire in Hunters Gulch (Shelly 1 988).

Biological interactions: Lesquerella klausii occurs most frquently in sparsely-vegetated slopes,
including disturbed areas such as unstable roadbanks. These observations suggest that it does not
compete well in dense vegetation and in closed forest stands.

POPULATION BIOLOGY

Population size and condition: Populations range in size from less than 20 to over 3000 individuals
(Poole and Heidel 1 993). In the study area, the population had over 1 00 plants in a single area. The
species was found long after flowering (July 22), and vegetative material was compared with specimens
for identification purposes.

Often where the species occurs in the Big Belt Mountains, it is found repeatedly in more than one
opening. Other openings in the study area were searched unsuccessfully, but the timing of the search
was so late as to leave room for question. It is possible that the Scratchgravel Hills occurrence
represents an accidental introduction by some unknown dispersal agent or is more extensive than initially
documented.

Population structure: A few first-year plants were observed. Most plants did not produce flowering
stalks, indicating a prevalent immature vegetative state or harsh conditions that year.

ASSESSMENT AND MANAGEMENT RECOMMENDATIONS

Threats to currently known populations: Mining, road maintenance and construction, and noxious
weed invasion and aerial herbicide application all pose threats among many of the known occurrences.
Two populations lie within the Red Mountain RNA and Cabin Creek RNA of the Helena National
Forest Service.

The Scratchgravel Hills population is dissected by the gravel road that leads to the top of the highest
summit. Leafy spurge (Euphorbia esula) is present along the roadside immediately below and adjoining
part of the population. It is just beginning to encroach the opening.

26

Management practices and response: Lesquerella klausii is tolerant of disturbance, as evidenced
by its ecological preference for open, somewhat unstable habitats. However, large-scale destruction or
invasion of this habitat could potentially result in extirpation of populations.

Recommendations for maintaining viable populations: Deliberate management actions are not
needed for maintaining the local population.

The exception is that general noxious weed control is needed along the summit road and intensive,
controlled spot treatment at the site of the Lesquerella klausii is recommented. This is the first site at
which leafy spurge is reported invading the species! habitat.

Recommendations for further assessment: It is recommended that distribution data continue to be
collected for this taxon as a state endemic species that is vulnerable, subject to periodic state rank
review. Its state status may be interpreted as basis for removing it from the Bureau of Management list
as a watch species but the threat of leafy spurge invasion may be interpreted as basis for its retention.

Most of the populations in the Big Belt Mountains are not subject to noxious weed encroachment to
date.

27

Oxytropis lagopus Nutt. var. conjugens Barneby

RABBIT-FOOT CRAZYWEED
Bean Family (Fabaceae)

STATUS

U.S. Fish and Wildlife Service: None.

U.S. Forest Service: None.

BLM: None

Other: It is given a Priority 2 rating in Canada (Argus and Pryer 1 990), and recommended for
consideration as a vulnerable species (Smith 1994).

Global rank: It is ranked G4T3 ; meaning that the species as a whole is potentially secure, but the
variety may be vulnerable.

State rank: It is ranked S3 , meaning that the variety may be vulnerable in the state. It was taken off of
the state species of special concern list in 1 993 and moved to the watch list because, despite its narrow
distribution, it is found in many places and it appears to increase under grazing pressure. Nevertheless, it
is a taxon of limited distribution.

DESCRIPTION

General Description: Rabbit-foot crazyweed is a cespitose perennial herb with a short, branching
woody stem at or below the surface (Figure 6). The foliage is densely silky-villous with long silvery
hairs. The stipules are membranaceous and densely silky-pilose dorsally, sometimes glabrate with age.
Leaves are 3-1 1 cm long usually 5-9 leaflets. Each leaflet is about the same length as the rachis.
Scapes are upright, 2- 1 3 cm long. The racemes are 5- 1 8 flowered. Bracts are shaggy-pilose dorsally,
often with dark hairs. The calyx is 8- 1 1 mm long, with silky hairs concealing the face of the tube that is
turgid to inflated at anthesis. The corolla is pink-purple, 13-16 mm long. The keel is 1 1 - 1 4 mm. Long.
The pod is erect, chartaceous to submembranaceous. The calyx is thickly hirsute, as long as the pod,
and usually persistent until after the pod dehisces (from Hitchcock et al. 1 984, Smith 1 994).

All varieties of OXYTROPIS LAGOPUS can be identified based on the pod that does not rupture and
is usually hidden by the calyx. Both OXYTROPIS LAGOPUS VAR. ATROPURPUREA and
OXYTROPIS LAGOPUS VAR. LAGOPUS are also present in Montana. But unlike O. L. VAR.
CONJUGENS, the calyx of the other varieties is usually deciduous with the enclosed pod before seed
dispersal, and they usually have more than nine leaflets, rarely as long as the rachis. ASTRAGALUS

28

PURSHII superficially resembles O. VAR. CONJUGENS in its hairiness, acaulescent growth form,
reddish-purple flowers and similar settings. But the rounded keel, and calyx which is shed before the
pond matures, distinguished it from OXYTROPIS LAGOPUS VAR. CONJUGENS.

GEOGRAPHICAL DISTRIBUTION

Global distribution: Oxytropis lagopus var. conjugens was considered to be a Montana endemic
until it was discovered in Alberta in 1 986. There, it is only found in the western section of the North
Milk River (Smith 1994).

Montana distribution: It occurs in foothills mainly east of the continental Divide between Jefferson and
Pondera counties, extending west as far as the Drummond area.

Montana counties: : Oxytropis lagopus var. conjugens is currently known from seven counties in
Montana: Granite, Jefferson, Lewis and Clark, Pondera, Powell and Teton counties, including many
scattered localities around the Helena Valley.

Historical distribution: The earliest known collection was made in 1 888 by Rev. F. D. Kelsey, giving
the location only as IHelenai. It was also collected before the turn of the century in an undated
collection made ifrom the vicinity of Deerlodgei. In addition, collections were made in 1 934 from the
Drummond and the Garrison areas.

Study area distribution: It is known from one point at the northeast end of the study area on a
ridgetop in Section 23, and is located immediately southwest of the study area as well in Sec. 3 1 .

HABITAT

Environment: Sparse sagebrush plains and grasslands to lower mountain slopes most often on
calcareous, well-drained substrates.

Soils: Soils are characteristically entisols or rocky loams, with high calcium carbonate concentrations.
The Scratchgravel Hills site is located on a gravel pavement of limestone.

Vegetation: The typical plant association is dominated by the plant association of bluebunch
wheatgrass (Psuedoroegneria spicata), as found at the study site. It has occasionally been found in low
elevation plant associations of needle-and-thread n needleleaf sedge {Stipa comata n Carexfilifolia;
Heidel 1997b). The associated species in the Scratchgravel Hills include:

29

Figure 6

Illustration by Jeanne R. Janish

From 'Vascular Plants of the Pacific Northwest'

Oxytropis lagopus van conjugens
Rabbitsfoot crazyweed

Chrysopsis villosa
Douglasia montana
Koeleria macrantha
Pseudoroegneria spicata
Selaginella densa

SPECIES BIOLOGY

Life history: Oxytropis lagopus var. conjugens belongs to a guild of early-flowering plants,
completing its flowering activity during May. This is an adaptation to its stressful habitat, taking
advantage of early-season moisture. Recruitment and longevity are not known.

Reproduction: Sexually reproducing by cross-pollination. Casual observations of seed-set show high
level of fertilization.

Dispersal: Unknown. The shaggy fruits fall to the ground.

Biological interactions: This species seems to occupy sparsely-vegetated slopes and knobs. This may
indicate that it is a poor competitor or has germination requirements for bare soil.

POPULATION BIOLOGY

Population size and condition: Plants were found at one point totaling less than 20 plants.

Population structure: Unknown. It may represent a segment of a larger population. The species is
dependent on insects for pollination.

ASSESSMENT AND MANAGEMENT RECOMMENDATIONS

Threats to currently known populations: Immediate threats to the population were not identified.
There are a few mining claims near it, signifying potential threat. It is at the top of a ridge slope that has
leafy spurge encroachment at its base, and it could be impacted by indiscriminate spraying of herbicides
and by noxious weed invasion in the future.

Management practices and response: Rabbit-foot crazy weed is an increaser under grazing (Heidel
pers. obs.) as is the crazyweed genus in general. Its rarity in the study area may reflect the paucity of
appropriate microhabitat and the good overall range conditions. Species of the crazyweed {Oxytropis)
genus are generally considered undesirable by stockmen because they cause ilocoismi that, in extreme
cases, kill livestock.

31

Recommendations for maintaining viable populations: Noxious weed invasion or indiscriminate
herbicide application are potential threats, though the high and dry settings in which this species occurs
are likely to be the least suitable and last sites to be encroached. Deliberate management actions are not
needed for maintaining the local Scratchgravel Hills population.

Recommendations for further assessment: It is recommended that distribution data continue to be
collected for this taxon as a limited distribution species subject to periodic state rank review. It is not
recommended for BLM status designation.

32

ECOLOGICAL RESULTS

Six plant associations were documented in the Scratchgravel Hills (Table 2). Status of plant
associations is determined by their rangewide rarity (geographic extent) and composition uniqueness, in
addition to attributes of the individual stands (quality and condition). The rangewide and statewide
status of the plant associations are reflected in global- and state- ranks. There were no rare or unique
plant associations documented in the study area, though exemplary individual stands of the
Pseudotsuga menziesn/Festuca scabrella plant association and the Pseudoroegneria spicata-
Bouteloua gracilis plant association were noteworthy for being diverse and relatively intact.

Table 2. Plant associations of the Scratchgravel Hills study area.
STRUCTURE PLANT ASSOCIATION

Woodland

Shrubland
Grassland

Pinus ponderosa/Pseudoregneria spicata p.a. G4 S4

Pseudotsuga menziesii/Festuca scabrella p.a.
Artemisia tridentata ssp. vaseyana /
Pseudoroegneria spicata p.a.
Pseudoroegneria spicata n Bouteloua gracilis
p.a.

Festuca idahonis n Pseudoregneria spicata
p.a.
Agropyron smithii-Bouteloua gracilis p.a.

CURRENT

PLOT NO.

RANK!

G4S4

001, 011,012,

013,015,017,

018

G4S4

008, 019

G5S5

005, 014

002, 003, 006,

007, 009, 010,

020, 021

G4S4

004

G5S4

016

The prevailing plant associations in the Scratchgravel Hills are the Pseudoroegneria spicata n
Rmjtplmmgrnrilisp Pi ^nH the Pinus pnndprnsn / Pspudnropgnprin spicata p.a. All Other plant
associations are inclusions within the other two associations and represent topographic, edaphic or
disturbance history conditions. Wetland plant associations are degraded and sparse in draw bottoms.

^ Ranking definitions

Gl SI Critically imperiled

G2 S2 Imperiled

G3 S3 Vulnerable

G4 S4 Potentially secure

G5 S5 Secure

GU SU Major unresolved status question precludes ranking

33

Vegetation Descriptions: WOODLAND TYPES

Pinus ponderosa/ Pseudoroegneria spicata plant association (G4 S4)

syn. Pinus ponderosalAgropy on spicatum or Pinus ponderosa/Elymus spicatus
(PINPON/PSESPI; ponderosa pine/bluebunchwheatgrass; 7 plots)

Environment: PINPON/PSESPI is the prevalent woodland type in the Scratchgravel Hills, covering
the highest hills, and part of some ridges and broken topography, including small outlying stands. It
forms a timbered iislandi in the Helena Valley. It spans the upper range of topographic positions, all
aspects, and the full range of slopes present in the landscape (0-35%); particularly steep slopes.

Soils: This vegetation type is most extensive and continuous on the highest hills, with their coarse,
relatively sterile sandy loams formed from intrusive igneous parent material, mapped as Woodgulch-
rock outcrop complex, 8-35% slope (Bingham et al. 1 977). It is well-developed but less extensive on
the loams and broken topography of sedimentary deposits to west, mapped as Whitecow-Roto-
Pensore channery loams, 8-35%) slope. It is ecotonal and discontinuous on the metamorphic parent
material and the Tertiary volcanics in between.

Vegetation: PINPON/AGRSPI in much of the Scratchgravel Hills approaches a closed-canopy
structure. This reflects the history of logging, and high levels of regeneration in the absence of fire. The
canopy cover of dense stands resembles forested vegetation, though the canopy height, and community
structure or lack of it, reflect the original woodland condition. The varied size classes of most stands
suggest that the logging history or at least the stand regeneration patterns were staggered rather than
episodic. There are many trees persisting in this plant association that probably pre-date settlement,
but they would have been sapling size before the turn of the century. For example, two typical trees of
Ponderosa pine and Douglas fir, both at about 8 in DBH were bored and determined to be 1 58 and
1 67 years old, respectively. The majority of canopy trees in much of this community are close to 1 00
years old and equal to or less than 5 in DBH. These trees and younger trees have an outermost zone of
rings that are very narrow and faint, a pattern which is interpreted to reflect canopy closure. Nearly all
of the few old-growth pine trees in the area that significantly predate settlement are outlying individuals
surrounded by grassland, including a few mature trees of over 35 in DBH. The historic PINPON/
AGRSPI p.a. may have had more of a savanna structure compared to current conditions. Research in
photographic archives may help resolve this matter.

In extreme cases of even-aged stand regeneration, there is almost no undergrowth. Mixed age stand
structure is found in all of the patchy and ecotone transition pine cover in the center, and in the more
broken topography at the west end. Among the latter are semi-open slopes with luxuriant grass cover
that may reflect natural parkland conditions, and they have high species diversity, with some of the
highest levels of litter cover found locally.

34

A significant component of Douglas fir {Pseudotsuga menziesn) is present throughout the plant
association, raising a question about the successional status of the PINPON/PSESPI p.a. as found in
the Scratchgravel Hills. The canopy cover of Douglas fir compared to ponderosa pine varies, but it
consistently matches or exceeds the cover of pine in the understory, often forming dog-hair patches of
saplings. It appears that Douglas-fir may be the climax type in the Hills in the absence of fire. Usually
Douglas-fir as climax type is restricted to settings with over 1 4i of annual precipitation, but the
Scratchgravel Hills would appear to be an exception. Limber pine {Pinusflexilis) is also present as a
canopy tree in low densities throughout much of the area, even on soils derived from igneous parent
material.

Typical herbaceous species on igneous parent material include small-flowered penstemon {Penstemon
procerus). Typical herbaceous species on sedimentary parent material vary with moisture regime but
include: moss phlox {Phlox bryoides), gray hawksbeard (Crepis intermedia), and ballhead sandwort
(Arenaria congesta). A local variant with an understory of bearberry {Arctostaphylos uva-ursi) was
found on patches of north-facing slopes and ridge-top barrens. Throughout much of the area,
particularly in closed canopies and on sterile soils, the undergrowth is very sparse and bare ground or
needle litter is exposed.

This type spans an array of parent materials and other environmental conditions, and has been most-
altered by disturbance among all plant associations in the Scratchgravel Hills. It has a pervasive logging
history. There were signs of recently logging of a couple mature trees. Mining activity was extensive. The
old adits, pits and connecting roads represent frontiers for noxious weed invasion. Evidence of a recent
wildfire within the past three years was found on a steep hillslope where less than an acre burned. The
increased tree density over much of the area is accompanied by a decrease in understory density, so
that woodland fires are unlikely to spread with the possible exception of high-intensity bums (stand-
replacing fires).

35

Pseudotsuga menziesii/Festuca scabrella plant association (G4 S4)

(PSEMEN/FESSCA: Douglas-fir/rough fescue; 2 plots)

Environment: North- and northeast-facing slopes at the head of Iron Gulch support a Douglas-fir
stand. This represents the most sheltered setting on the largest promontory of the study area. The Hills in
general represent an unusually arid setting for such a mesic plant association.

Soils: The soils are mapped as Woodgulch-rock outcrop complex, 8-35% slope, a loamy sand
(Bingham et al. 1 977). The litter and duff layers are deep compared to the other local communities, and
the organic content of the soil may account for its relatively high moisture-holding capacity.

Vegetation: The PSEMEN/FESSCAp.a. present in the Hills is floristically well-developed, locally
distinct, and relatively diverse. Over half of the stand is relatively open with about 50% tree canopy
cover and dominated mainly by large, old-growth Douglas fir trees. Most have been damaged by
lightening or wind. The oldest trees are over 300 years old, as deteremined by cores. The remainder of
the stand is dominated by pole-size and mature timber. The cover of rough fescue (Festuca scabrella)
varies with canopy closure, ranging from 30%) under closed canopy to 90%) under open canopy.

The undergrowth in well-developed settings has a major component of old manis whiskers (Geum
triflorum; 20%o) and a milkvetch (Astragalus miser; up to 5%)). The moss cover was far higher than in
other local plant associations (1 0-20%)) reflectng both mesic conditions and lack of disturbance. Other
vascular plant species in this community which were not found elsewhere locally include nodding onion
(Allium cernuum), pasquefiower (Anemone patens), heart-leaved arnica (Arnica cordifolia), small-
fiowered blue-eyed Mary (Collinsiaparviflora), northern hedysarum (Hedysarum boreale) and
small-leaved alumroot (Heucheraparvifolia).

36

Vegetation Descriptions: SHRUBLAND TYPE

Artemisia tridentata ssp. vaseyana I Pseudoroegneria spicata plant association

fsyn. Artemisia tridentata/Agropyron spicatum, Artemisia tridentata/Elymus spicatus)

(G5 S5)
(ARTTRV/PSESPI; /mountain big sagebrush/bluebunch wheatgrass; 2 plots)

Environment: ARTTRV/PSESPI occurs in small, discretely different environmental settings, perhaps
representing an assortment of microhabitats that have a longer fire-free interval. These include exposed
segments of steep, open hillsides; small, level openings within woodland; and small bald spots on open
ridge. It was sampled on a south-facing, midslope spur surrounded by a sparse PSESPI-BOUGRA
p.a. above Iron Gulch, and in a level woodland opening surrounded by a PINPON/PSESPI p.a. in the
breaklands north of Echo Lane.

Artemisia tridentata is also abundant but secondary to Pseudoroegneria spicata on the alluvium that
flanks the eastern end of the Scratchgravel Hills study area, and on a variety of small ridgeline barrens
with a continuous range of cover values variously making it dominant or secondary.

Soils: The two sample sites have Hauz-Tolman channery loam and the loamy Musselshell-Crago
complex, derived from metamorphic and sedimentary materials, respectively.

Vegetation: These shrubland associations more closely resemble the grassland associations in the
vicinity than they resemble one another. Sample plots are provisionally assigned to mountain big sage
dominance {Artemisia tridentata ssp. vaseyan^, though Wyoming big sage {Artemisia tridentata
ssp. wyomingensis) is also common in the grassland perimeter. The latter is not known as a dominant
in the study area, but is perhaps most abundant on alluvium at the east end. This taxonomic distinction
between these subspecies, representing the prevalent Rocky Mountains subspecies and Great Plains
subspecies, warrants closer on-site evaluation. The two plots differ greatly in shrub stature
corresponding with slope and moisture. Besides dominant species, they have Hoodis phlox {Phlox
hoodii) and fringed sage {Artemisia frigida) in common.

37

Vegetation Descriptions: GRASSLAND TYPES

Pseudoroegneria spicata n Bouteloua gracilis plant association (G4 S4)

syn. Agropyron spicatum n Bouteloua gracilis; Elymus spicatus n Bouteloua gracilis
(PSESPI-BOUGRA; bluebunch wheatgrass-blue grama; 8 plots)

Environment: The PSESPI-BOUGRA p.a. encircles most of the Scratchgravel Hills on the flanks,
toeslopes and exposed ridge slopes, as well as on the alluvium at the eastern end. It occupies all
topographic positions, depending on the aspect and substrate. Typical and extreme sites were sampled
including an exposed ridgetop, the steep ridge slopes at the north end, and the expansive grassland
margins on the south side. There are some forested openings in the western end dominated by
bluebunch wheatgrass with a well-developed grassland flora that are treated as wooded plant
associations though tree cover is less than 30%.

Soils: Soils are channery loams and sandy loams. The particle size for the latter is just short of the
gravel size class. Bare soil or the icoarse-sandi covers over 50% to nearly all the ground surface.

Vegetation: Bluebunch wheatgrass is dominant in the Hills, without the widely-recognized co-
dominants of Sandbergis bluegrass {Poa seconda) in montane settings, or blue grama {Bouteloua
gracilis) in plains settings. The only exception where there is a blue grama component of 5%o or greater
is found on the lowest elevation sites. This corresponds with the alluvial flats at the eastern end on of the
study area. Elsewhere blue grama is in trace amounts, andjunegrass {Koeleria macranthera)
contributes a relatively larger component. The paucity of blue grama may be due to the fact that it has a
shallow root system not suited to the droughty upper horizons of local soils, or that it is a warm-season
(C4) grass not suited to the cool-season growth fostered by the setting.

The plant association has a conspicuous bunchgrass appearance, typically with about 30%) cover by
Pseudoroegneria spicata; ranging from about 1 5-50%) on exposed ridgelines and as forest inclusions,
respectively. Species composition changes dramatically with the moisture gradient and substrate, and
sample plots in this p.a. had high species diversity individually and collectively.

This is also the prevailing plant association of the Fort Harrison Military Reservation nearby on the south
side of the Sevenmile Creek (Ken Scow pers. commun.). It was also observed on lands to the west,
and considered as typical for the Helena Valley.

38

Festuca idahoenis - Pseudoroegneria spicata plant association (G4 S4)

syn. Festuca idahoensis-Agropyron spicatum, Festuca idahoensis-Elymus spicatus
(FESIDA-AGRSPI;bluebunchwheatgrass-Idaho fescue; 1 plot)

Environment: FESIDA-AGRSPI p.a. is on a steep, east-facing, open side-ridge surrounded by
woodland. It is thought to represent a localized grassland climax in the more sheltered settings on the
contact metamorphics that are in broken bands around the highest hills.

Soils: Soils mapping does not distinguish this area from the surrounding Woodgulch-rock outcrop
complex derived from granidiorite, yet the soils were rocky relatively deep, with a loamy texture; and
species composition indicated a high calcium concentration.

Vegetation: This is provisionally treated as discrete from the preceding p.a. based on the significant
Festuca idahoensis component and the highest local cover values recorded for pussytoes {Antennaria
spp.) and compact selaginella {Selaginella densa). It is the only p.a. with plant material making up over
50% of ground cover, and has relatively high total grass cover (close to 50%). Some of the more
locally distinguishing associated species included: Rocky Mountain douglasia (Douglasia montana),
Rocky Mountain woodsia (Woodsia scopulina), and wiry milkvetch (Astragalus flexuosus). It also
harbored linearleaf fleabane {Erigeron lineare).

Pascopyrum smithii -Bouteloua gracilis p.a. (G5 S4)

Syn. Agropyron smithii-Bouteloua gracilis, Elymus smithii-Bouteloua gracilis
(PASSMI-BOUGRA; western wheatgrass-blue grama; 1 plot)

Environment: PASSMI-BOUGRA is a Great Plains plant association found in one large toeslope area
on the south side of the Hills, gently rolling at less than 1 0% slope.

Soils: It is mapped as Crittenden sandy loam, very rocky; but appeared in the field as an even-textured
silt loam.

Vegetation: This is the only rhizomatous grassland community in the Hills, and it is a vigorous example
with over 50%o grass cover total. It has plains species that are absent or rare elsewhere locally, including:
green sage (Artemisia dracunculus), scarlet globe-mallow (Sphaeralcea coccinea) western gromwell
(Lithospermum ruderale), Indian wheat {Plantago patagonica) and rush skeletonweed (Lygodesmia
juncea).

39

DISCUSSION

The results of the Scratchgravel Hills baseline survey represent a ibiological crossroads! pattern, made
up four sets of noteworthy features:

1 . Lesser rushy milkvetch {Astragalus convallarius) is a rare Great Basin plant species that is
disjunct and at the northern end of its range in the Helena Valley. It is among the four best
examples in the state, and is one of two or three that are primarily on public land without
competing uses.

2. Linearleaf fleabane (Erigeron linearis) is a rare Columbia Plateau plant species that is
disjunct and at the eastern end of its range in the Helena Valley. Though the population is small,
it is the best of the two occurrences in the state for which detailed information is available.

3 . Two taxa are present that are recognized on the watch list because they live primarily or
exclusively in Montana and nowhere else in the world (iendemici), though they are not under
apparent threat. They are present in the Scratchgravel Hills in low numbers, including Klausi
bladderpod (Lesquerella klausii) and rabbitsfoot crazyweed (Oxytropis lagopus var.
conjugens).

4. Two relatively intact and well-developed Rocky Mountain plant associations are
noteworthy for their site-specific conditions though not for their plant association rarity; the
Douglas-fir/rough fescue plant association (Pseudotsuga menziesii/Festuca scabrella p.a.),
and the foothills form of the bluebunch wheatgrass plant association (Pseudoroegneria
spicatum n Bouteloua gracilis p.a.). The Douglas-fir/rough fescue p.a. is a well-developed
and relatively intact Rocky Mountain vegetation type has an old-growth component and an
exceptionally mesic flora for such a dry landscape. The bluebunch wheatgrass n blue grama p.a
is also a relatively intact Rocky Mountain vegetation type.

One of these, the lesser rushy milkvetch occurrence, represents among the best examples in the state.
Two more of these represent the only documented examples in the Helena Valley and among the most
unusual examples in the state, including the linearleaf fleabane occurrence and the Douglas fir/rough
fescue plant association.

The combination of botanical and ecological features in the Scratchgravel Hills points to an existing
opportunity to safeguard state-level biodiversity in the Headwaters Resource Area. The most serious
imminent threats to these values are noxious weed encroachment, summarized in this paragraph. Leafy
spurge {Euphorbia esula) is invading along the watercourses, most serious along the Iron Gulch road
and bottoms, Iowa Gulch and the watercourse below Echo Drive. It is invading along upland roads,
with sporadic encroachments even along the spur to the summit. It is found at a few mine sites, and is
uncommon in undisturbed natural habitat, perhaps dispersed by animals that are known to feed on it.

40

like whitetail deer or mourning doves. Spotted knapweed {Centaurea maculosa) is the noxious weed
most consistently found at old mine sites, including pits where it is in broad, dense swathes. It is also
readily distributed along roads and trails, and is usually present in the same settings where leafy spurge is
found. Diffuse knapweed (Centaurea diffusa) is less common of the three species and is found on the
finger ridge above Echo Drive and at the far eastern end on alluvium. Yet the Scratchgravel Hills have
low weed numbers compared to some of the surrounding lowlands, suggesting that they may be a sink
rather than a source. In light of their central location, and the wind and wildlife distribution vectors of the
weeds, the Hills could become a major source of noxious weeds in the Helena Valley if Scratchgravel
Hills infestations are not kept in check.

This study documents two Montana plant species of special concern and two outstanding plant
associations that are unprotected or only partially protected elsewhere in the Helena valley. In the
evaluation process, we have ruled out the presence of globally imperiled features or exemplary state
botanical and vegetation features. The relative state biodiversity significance of the Scratchgravel Hills
hinges on a few unknown factors. These include:

1 . The species! status of lesser rushy milkvetch is likely to be refined or confirmed with more survey
work and information on its persistence, e.g., at the Chatham site.

2 . The protection status of low elevation sites of Douglas-fir/rough fescue in Montana are to be
reviewed among Forest Service protected areas to evaluate the relative significance of the
Scratchgravel Hills stand.

3 . The success at curtailing noxious weed invasion in the Hills conditions the viability of these
Scratchgravel Hills features into the future.

This study does not integrate recreation values, cultural values or animal biodiversity and values
associated with game or nongame species; all of which factor into effective management planning. It
does contribute to the landscape overview and inventory of resources, for further management
consideration and reference.

41

LITERATURE CITED

Argus, G. W. and K. M. Pryer. 1 990. Rare Vascular Plants in Canada n Our Natural Heritage.
Canadian Museum of Nature. Ottawa, Ontario. 1 91 pp. + maps.

Bameby, R. C. 1964. Atlas ofl^orthArnQvicanAstragalus. Memoirs of the New York Botanical
Garden. 13:1-1188.

Bingham, L. C, A. Silvemale, P E. McCain and S. D. Spano. 1 977. Soil Survey of the Helena Valley.
U.S. D. A. Soil Conservation Service. Bozeman, MT.

Bourgeron, P. S. and L. D. Engelking, eds. 1 994. Apreliminary vegetation classification of the western
United States. Unpublished report by the Western Heritage Task Force for The Nature
Conservancy, Boulder, CO.

Bureau of Business and Economic Research, 1 998. State economic forecast news release as highlighted
in Independent Record article by Bob Anez, Associated Press. 28 January 1 998, 8 A. Missoula,
MT

Cooper, S. v., R. W. DeVehce andT McGarvey. 1995. Classification of southwestern Montana plant
communities with emphasis on those of the Dillon Resource Area. Unpublished report to the
Bureau of Land Management. Montana Natural Heritage Program, Helena. 1 54 pp.

Daubenmire, R. D. 1 959. A canopy-coverage method of vegetation analysis. Northwest Science 33 :43-
66.

Dom, R. D. 1 984. Vascular plants of Montana. Mountain West Publishing, Cheyenne, WY. 276 pp.

Heidel, B. L. 1997a. Montana plant species of special concern. UnpubUshed Ust. Montana Natural
Heritage Program, Helena. 34 pp.

Heidel, B.L.I 997b. Botanical survey of the Alkali Lake area. Unpublished report to the U.S. Fish and
Wildlife Service and Blackfeet Nation. Montana Natural Heritage Program, Helena. 35 pp. +
app.

Heidel, B. L. and J. Vanderhorst. 1 996. Sensitive plant surveys in Beaverhead and Madison counties,
MT. Unpublished report to the Bureua of Land Management. Montana Natural Heritage
Program, Helena. 85 pp + app.

42

Herrin, J., G. Walker, C. V. Baltzer and M. Ratcliff. 1 987. Road Log No. 1 . Economic geology of the
Greater Helena Area - Helena to Montana Tunnels Mine, Lump Gulch, Grizzly Gulch, Fort
Harrison and Marysville. R 1-12. In: R. B. Berg and R. H. Breuninger. 1987. Guidebook of the
Helena Area, West-Central Montana. Special Publ. 95. Montana Bureau of Mines and
Geology, Butte. 64 pp.

Hitchcock, C. L. andA. Cronquist. 1984. Vascular Plants of the Pacific Northwest. Vol. 3.
Saxifragaceae to Ericaceae . University of Washington Press, Seattle. 614 pp.

Horn, G 1980. Report on inventory of threatened or endangered, rare, or sensitive plants-Headwaters
Resource Area, Butte District, Bureau of Land Management, Montana. Unpublished report. 54
pp.

Lorenz, H. H. and F. A. Sweason. 1951. Geology and Groundwater Resources of the Helena Valley,
Montana. U.S. Geological Survey, Circular 83.

Montana Native Plant Society. 1993. Guidelines for collection of native plants. Kelseya 6(3):4.

Phillips, H. W. 1 997. Plants and plant communities, pp. 47-62. In: Turin, E. and R. Bourie, eds.
Exploring Mount Helena. Falcon Press. 1 00 pp.

Poole, J. M. and B. L. Heidel. 1 993 . Sensitive plant surveys in the Big Belt and Elkhom Mountains,
Helena National Forest. Unpublished report to the Helena National Forest. Montana Natural
Heritage Program. Helena, MT. 129 pp. + app.

Rollins, R. C. 1984. Studies in the Cruciferae of western North American. Contributions Gray
Herbarium214:l-18.

Rollins, R. C. 1993. The Cruciferae of Continental North America: Systematics of the mustard family
from the Arctic to Panama. Stanford Univ. Press, Stanford, CA. 976 pp.

Rollins, R. C. and E. A. Shaw. 1 973 . The genus Lesquerella (Cruciferae) in North America. Harvard
University Press, Cambridge, MA 288 pp.

Ross, C. P, D. A. Andrews, and L G Witkind. 1955. Geological map of Montana (1 :500,000).
Montana Bureau of Mines, Butte.

Scow, K. L., L. D. Culwell, and L. A. Larsen. 1986. Vegetation inventory of the Chartam Project Area,
Broadwater County, Montana. Western Energy Company unpublished report.

43

Scratchgravel Hills Planning Committee and Lewis and Clark Areawide Planning Organization. 1 984.
Scratchgravel Hills Comprehensive Management Plan. Unpublished plan for Lewis and Clark
County Commission and Planning Board. 48 pp.

Shelly, J. S. 1988. Status review of Lesquerella klausii, Helena and Lewis & Clark National Forests.
Unpublished report to U.S. Forest Service, Region 1, Missoula. Montana Natural Heritage
Program, Helena, MT. 82 pp.

Smith, B. 1 994. Status report on hare-footed locoweed (Oxytropis lagopus Nutt.) in Canada.

Unpublished report. Committee on the Status of Endangered Wildlife in Canada. 22 pp. + fig.

USDI Bureau of Land Management. 1996. Special status species management. BLM Manual
Supplement 6840 of 8 April 1996. Billings, MT.

USDI Department of Commerce. 1 982. Monthly normals of temperature, precipitation, and heating and
cooling degree days, 1951-1980. National Oceanic and Atmospheric Administration,
Climatography of the United States No. 8 1 . 23 pp.

Vanderhorst, J. 1 995. Report on the conservation status oi Lesquerella carinata var. languida, a

candidate threatened species. Unpublished report to the Bureau of Land Management. 56 pp. +
app.

44

Appendix A. Element Occurrences

Scientific Name: ASTRAGALUS CONVALLARIUS
Common Name: LESSER RUSHY MILKVETCH

Global rank: G5T5
State rank: S2

Forest Service status:
Federal Status:

Element occurrence code: PDFAB0F2D1 . 009
Element occurrence type:
Survey site name: SCRATCHGRAVEL HILLS
EO rank comments:

EO rank:

County: LEWIS AND CLARK

USGS quadrangle: AUSTIN, SCRATCHGRAVEL HILLS

Township: Range: Section: TRS comments:

OllN 004W 29 NW4; 20 SW4 ; 27 SW4 ; 28; 31 W2; 33 E2; 34 NW4

OlON 004W 4 NE4

Precision:

Survey date:

First observation:

Last observation:

1997-07-31 Elevation: 4300 - 4800
1997-06-20 Slope/aspect: 0-15%/ALL ASPECTS
1997-07-31 Size (acres):

Location: SCRATCHGRAVEL HILLS, NNW OF HELENA.

Element occurrence data:

CA. 5000+ PLANTS WIDELY DISPERSED IN MANY LOW DENSITY SUBPOPULATIONS
ACCROSS FULL RANGE OF SPECIES' POTENTIAL HABITAT. FLOWERING LATE JUNE
TO MID-AUGUST IN 1997. TYPICALLY SINGLE-STEMMED, BUT SECTION 31 HAD
ROBUST, MULTI-STEMMED ROOT CROWNS.

General site description:

OPENINGS, OPEN WOODS, AND ON GRASSLANDS ADJOINING WOODS AND DRAINAGE
COURSES, ON MAINLY LOAMY SOILS OF MAINLY SEDIMENTARY ORIGIN. WHILE IT
OCCUPIES THE PREVALENT ASSOCIATIONS OF AGROPYRON SPICATUM WITHOUT
PINUS PONDEROSA, IT IS OFTEN AT ECOTONES OR TRANSITIONS WITHIN THE
MATRIX. ASSOCIATED SPECIES VARIOUSLY INCLUDE CREPIS INTERMEDIA,
ZIGADENUS VENOSUS, PHLOX MUSCOIDES, CHRYSOPSIS VILLOSA, BOUTELOUA
GRACILIS, STIPA COMATA OR FESTUCA SCABRELLA.

Land owner/manager:

BLM: BUTTE DISTRICT, HEADWATERS RESOURCE AREA
PRIVATELY OWNED LAND (INDIVIDUAL OR CORPORATE)

Comments :

THE HIGHEST DENSITIES ARE IN THE SECTION 31 WATERCOURSE FOLLOWED BY
THE SECTION 20 FOREST OPENINGS. LEAFY SPURGE AND SPOTTED KNAPWEED ARE
IMMINENT THREATS.

Information source :

HEIDEL, BONNIE. [BOTANIST] MONTANA NATURAL
HERITAGE PROGRAM, 1515 EAST SIXTH AVENUE, P.O. BOX
201800, HELENA, MT 59620-1800. WORK: 406/444-3009.

Specimens: HEIDEL, B. (1562). 1997. MONTU.

HEIDEL, B. (1570, 1595). 1997. MONT.

Scientific Name: ERIGERON LINEARIS
Common Name: LINEARLEAF FLEABANE

Global rank: • G5 Forest Service status: SENSITIVE
State rank: SI Federal Status :

Element occurrence code: PDAST3M2B0 . 004

Element occurrence type:

Survey site name: SCRATCHGRAVEL HILLS

EO rank:
EO rank comments:

County: LEWIS AND CLARK

USGS quadrangle: SCRATCHGRAVEL HILLS

Township : Range : Section : TRS comments :
OllN 004W 28 SE4; 26 NE4SW4

Precision: S

Survey date: Elevation: 4400 - 4480

First observation: 1997-06-21 Slope/aspect: 2-30%/SOUTH AND EAST

Last observation: 1997-06-24 Size (acres) : 1

Location:

CA. 4 MILES NORTHWEST OF HELENA; ACCESSIBLE VIA ECHO DRIVE ON THE WEST
SIDE OF THE SCRATCHGRAVEL HILLS, AND VIA NORRIS ROAD TURN ON THE EAST
SIDE.

Element occurrence data:

OVER 200 PLANTS IN TWO SUBPOPULATIONS, LOCALLY COMMON IN SMALL
CLUSTERS IN SECTION 28, BUT OCCASIONAL AND MORE SPREAD OUT IN SECTION
26; BOTH WITH VIGOROUS MULTI-STEMMED CLUMPS. PLANTS IN SECTION 28 WERE
STILL FLOWERING IN LATE JUNE WHEN THOSE IN SECTION 2 6 HAD NEARLY
FINISHED, EVEN THOUGH THE SECTION 28 SETTING SEEMED MUCH MORE ARID AND
HARSH.

General site description:

TWO CONTRASTING SETTINGS INCLUDING A STEEP GRASSLAND SLOPE OPENING
SURROUNDED BY FOREST WITH AGROPYRON SPICATUM-FESTUCA IDAHOENSIS HT
PLUS LOMATIUM TRITERNATUM, HAPLOPAPPUS ACAULIS AND SENECIO CANUS; AND
A SPARSELY-VEGETATED SAGE BALD ON AN OPEN BENCH DOMINATED BY ARTEMISIA
TRIDENTATA AND AGROPYRON SPICATUM WITH LEWISIA REDIVIVA AND ERIGERON
COMPOSITUS.

Land owner/manager:

BLM: BUTTE DISTRICT, HEADWATERS RESOURCE AREA

Comments :

SURVEY IN SECTION 26 WAS NOT COMPLETE BECAUSE PLANTS WERE NOT IN
FLOWER.

Information source: HEIDEL, BONNIE. [BOTANIST] MONTANA NATURAL

HERITAGE PROGRAM, 1515 EAST SIXTH AVENUE, P.O. BOX
201800, HELENA, MT 59620-1800. WORK: 406/444-3009.

Specimens: HEIDEL, B. L. (1567, 1568). 1997. MONTU.

Appendix B. Photo Documentation

1 . Lesser rushy milkvetch {Astragalus convallarius)

2. Linearleaf fleabance (Erigeron linearis)

3. Klausibladderpod (Lesquerella klausii)

4. Woodland opening habitat supporting Klausibladderpod

5. Rabbitsfoot crazy weed (Oxytropis lagopus var. conjugens)

6. Bluebunch wheatgrass perimeter; looking south to Helena

7. Typical ponderosa pine^luebunch wheatgrass plant association

8. Coring mature Douglas-fir in the Douglas-fir/rough fescue plant association

9. Bitterroot (Lewisia rediviva), a common plant in the Scratchgravel Hills

Not reproduced in on-line version. See Rare Plant Field Guide, http://nhp.nris.state.mt.us/plants/index.html

Appendix C. Preliminary flora of the Scratchgravel Hills^

Trees

Juniperus scopulorum
Pinus flexilis
Pinus ponderosa
Populus acuminata
Prunus mahaleb
Pseudotsuga menziesii

Shrubs and vines

Arctostaphylos uva-ursi

Artemisia frigida

Artemisia tridentata ssp. vaseyana

Artemisia tridentata ssp. wyomingensis

Ceratoides lanata

Chrysothamnus nauseosus

Chrysothamnus viscidiflorus

Clematis ligusticifolia

Gutierrezia sarothrae

Rhus aromatic a

Ribes aureum

Ribes cereum

Rosa woodsii

Shepherdia canadensis

Symphoricarpos spp.

Grasses and grass-hke plants

Agropyron cristatum^

Aristida longiseta

Bouteloua gracilis

Bromus inermis^

Bromus japonicus *

Bromis tectorum^

Calamagrostis purpurascens

Carex filifolia

Carex geyeri

Carex petasata

Carex stenophylla

Elymus lanceolatus (Agropyron dasystachyum)

Elymus smithii (Pascopyrum smithii)

Elymus spicatus (Pseudoregneria spicata)

Festuca idahonis

Festuca scabrella

Koeleria macrantha

Muhlenbergia cuspidata

Oryzopsis hymenoides

Poa nevadensis

Poa pratensis^

Poa secunda

Stipa com at a

Stipa viridula

^ An asterisk after the species name indicates that the species is exotic (non-native).

Herbs (includes ferns)
Achillea millefolium
Allium cernuum
Allium textile
Anemone patens
Antennaria dimorpha
Antennaria parvifolia
Antennaria plantaginea
Antennaria spp.
Achillea millefolium
Allium cernuum
Allium textile
Alyssum desortorum *
Amaranthus albus
Ambrosia spp.
Androsace occidentalis
Anemone patens
Antennaria corymbosa
Antennaria microphylla
Antennatria parvifolia
Arabis holboellii
Arabis microphylla
Arenaria congesta
Arnica cordifolia
Artemis a campestris
Artemisia dracunculus
Artemis a ludoviciana
Aster alpigenus
Astragalus agrestis
Astragalus bisulcatus
Astragalus convallarius
Astragalus flexuosus
Astragalus gilviflorus
Astragalus lotiflorus
Astragalus miser
Astragalus purshii
Camelina sativa"^
Campanula rotundifolia
Castillejaflava
Centaur ea diffusa"^
Centaurea maculosa'^
Chenopodium album"^
Chenop odium fremontii
Cirsium undulatum
Chrysopsis villosa
Collinsia parviflora
Comandra umbel I at a
Convolvulus arvensis"^
Conyza canadensis
Coryphantha miss our iensis
Crepis acuminata
Crepis intermedia
Cryptantha torreyi

Cymopteris acaulis
Cynoglossum offinale"^
Cystopteris fragilis
Descurainia pinnata"^
Dodecatheon conjugens
Douglasia montana
Draba reptans
Erigeron caespitosum
Erigeron compos itus
Erigeron lineare
Eriogonum flavum
Eriogonum spp. (E. mancum?)
Eriogonum umbel latum
Erysimum asperum
Euphorbia esula"^
Evolvulus nuttallii
Filago arvensis
Fragaria virginiana
Gaillardia aristata
Galium boreale
Gaura coccinea
Gayophyton spp.
Geum triflorum
Grindelia squarrosa
Hackelia floribunda
Haplopappus acaulis
Hedysarum boreale
Heuchera parvifolia
Hymenopappus filifolius
Hymenoxys acaulis
Hymenoxys richardsonii
Hyoscyamus niger"^
Lappula redowskii
Lepidium densiflorum
Lepidium perfoliatum *
Leptodactylon pungens
Lesquerella alpina
Lesquerella klausii
Lewisia rediviva
Liatris punctata
Linaria dalmatica"^
Linum lewisii
Lithospermum incisum
Lithospermum ruder ale
Lomatium macrocarpum
Lomatium triternatum
Lygodesm ia juncea
Medicago lupulina"^
Me die ago sativa"^
Melilotus officinalis *
Mentzelia dispersa
Musineon divaricatum
Nothocalais troximoides
Oenothera cespitosa

Opuntia polyacantha

Orobanche fasciculata

Oxytropis lagopus van conjugens

Oxytropis sericea

Paronychia sessiliflora

Pens tern on diphyllus

Pens tern on eri anther us

Penstemon nitidus

Pens tern on procerus

Phlox albomarginata

Phlox bryoides

Phlox hoodii

Plantago patagonica

Polygonum spp.

Potentilla spp. (P. concinna?)

Potentilla glandulosa

Salsola kali"^

Sedum lanceolatum

Selaginella densa

Senecio canus

Sisymbrium altissimum

Solidago occidentalis

Solidago spp.

Sphaeraclea coccinea

Stephanomeria runcinata

Taraxacum offinale"^

Townsendia hookeri

Tragopogon miscellus

Trifolium spp. *

Verbascum thapsus"^

Viola nuttallii

Appendix D. ECOD ATA analysis

Not reproduced in on-line version. To see ECOD ATA, please contact Montana Natural Heritage Program