Astragalus purshii Douglas ex Hook. var. purshii
woollypod milk-vetch (woollypod milkvetch)
Fabaceae (Pea family)

Introduction to Vascular Plants

Photograph

© Paul Handford     (Photo ID #65439)


Map

E-Flora BC Static Map

Distribution of Astragalus purshii var. purshii
Click here to view the full interactive map and legend

Species Information

General:
Perennial herb from a taproot and branching stem-base; stems prostrate, tufted or mat-forming, 5-10 cm long, greyish-woolly with unbranched hairs.
Leaves:
Alternate, pinnately compound, crowded, 2-15 cm long, white-woolly; leaflets 5 to 19, elliptic or oval to oblong, 5-20 mm long; stipules membranous, lanceolate, long-pointed, 3-15 mm long, usually exceeding the internodes, not joined at the base.
Flowers:
Inflorescence a short, axillary raceme of 2 to 10 pea-like flowers, the raceme-stalks from shorter to longer than the leaves, sometimes almost lacking, arching or lying on the ground in fruit; corollas yellowish-white to reddish-purple, 1-3 cm long, the banner longer than the wings and the blunt keel; calyces cylindric, 12-16 mm long, black- to grey-hairy, the narrowly lanceolate teeth 1/3-1/2 as long as the tube.
Fruits:
Pods, egg-shaped or narrowly ellipsoid, spreading, unstalked, 1-2.5 cm long, leathery, greyish-woolly, somewhat flattened, straight to curved, 1-chambered.
Notes:
Two intergrading varieties of this highly variable species are recognized in BC.

1. Flowers yellowish-white or pale lavender, the keels purple-tipped; pods nearly straight.................. var. purshii

1. Flowers reddish-purple; pods curved and strongly grooved............... var. glareosus (Dougl. ex Hook.) Barn.

SourceThe Illustrated Flora of British Columbia

Illustration

If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.

Ecology

Ecological Framework for Astragalus purshii var. purshii

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class

Avg

Min

Max

Elevation (metres)
869 635 1104
Slope Gradient (%)
16 11 22

Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]

64 150 340
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
2 1 4
Modal Nutrient Regime
Class
A
# of field plots
 species was recorded in:
2
Modal BEC Zone Class
BG

All BEC Zones (# of stations/zone) species was recorded in

BG(1), IDF(1)

Habitat and Range

Dry grasslands and sagebrush scrub in the steppe and lower montane zones; common in SC BC; E to AB and S to SD, ND, CO, NV and NE CA.

SourceThe Illustrated Flora of British Columbia

Synonyms

Synonyms and Alternate Names:
Astragalus incurvus (Rydb.) Abrams
Astragalus purshii var. interior M.E. Jones