Astragalus alpinus L.
alpine milk-vetch (Alaskan sagebrush; alpine milkvetch)
Fabaceae (Pea family)

Introduction to Vascular Plants

Photograph

© Virginia Skilton     (Photo ID #2755)


Map

E-Flora BC Static Map

Distribution of Astragalus alpinus
Click here to view the full interactive map and legend

SUBTAXA PRESENT IN BC

Astragalus alpinus var. alpinus

Species Information

General:
Low mat-forming perennial herb from a taproot and rhizomes; stems few to several, decumbent to ascending, 5-35 cm long, slender, branched, with short, appressed, unbranched hairs.
Leaves:
Alternate, pinnately compound, 5-15 cm long, stalked; leaflets 13 to 25, egg-shaped to oblong-elliptic, rounded to notched at the tip, 5-15 (20) mm long, appressed-hairy, the stalks equal to or longer than the leaves; stipules 1-8 mm long, the lower ones joined and clasping the stem.
Flowers:
Inflorescence a short, axillary raceme of 5 to 30 pea-like flowers, the flowers ascending at first, later nodding, the racemes 1-6 cm long on stalks from shorter to longer than the leaves; corollas pinkish- to bluish-purple, often white towards the base, 7-15 mm long, the darker-purple keel about as long as the banner, both longer than the wings; calyces bell-shaped, short-black-hairy, 3-6 mm long, the awl-shaped teeth about half the length of the tube.
Fruits:
Pods, ellipsoid-oblong, drooping from a slender stalk about as long (1-3 mm) as the calyx teeth, black appressed-hairy, membranous, 8-17 mm long, grooved below, almost 2-chambered, the partition sometimes nearly complete.

SourceThe Illustrated Flora of British Columbia

Ecology

Ecological Framework for Astragalus alpinus

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)
1805 33 2682
Slope Gradient (%)
27 0 100

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

171 10 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
2 0 6
Modal Nutrient Regime
Class
C
# of field plots
 species was recorded in:
218
Modal BEC Zone Class
ESSF

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

AT(42), BAFA(26), BWBS(10), ESSF(74), IMA(16), MH(12), MS(8), SBPS(5), SBS(1), SWB(12)

Habitat and Range

Moist to mesic streambanks, river terraces, meadows, rocky slopes, heath, tundra and open forests in the montane to alpine zones; frequent in BC east of the Coast-Cascade Mountains; N to AK, YT and NT, E to NF and S to ID, MT, NM, NV, WA and NE OR.

SourceThe Illustrated Flora of British Columbia