Astragalus filipes Torr. ex A. Gray
threadstalk milk-vetch (basalt milkvetch)
Fabaceae (Pea family)

Introduction to Vascular Plants


© Virginia Skilton     (Photo ID #16025)


E-Flora BC Static Map

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

Species Information

Perennial herb from a thick, woody taproot and branching stem-base; stems several to numerous, slender, erect, 30-70 cm tall, often branched, with short, appressed, unbranched hairs.
Alternate, pinnately compound, 5-10 cm long, short-stalked; leaflets 9 to 21, narrowly oblong-elliptic, 5-20 mm long, glabrous or grey-hairy above; stipules triangular, 1-3 mm long, the lower ones fused into a papery sheath, the upper free.
Inflorescence a loose, axillary raceme of 10 to 30 spreading to nodding, pea-like flowers, the racemes somewhat 1-sided, elongating in fruit to about equal the 6- to 20-cm long stalk, the stalks exceeding the leaves; corollas cream-coloured, 9-13 mm long, the wings shorter than the banner but longer than the keel; calyces blackish- or partly white-hairy, 4-6 mm long, the triangular teeth 1 mm long.
Pods, narrowly oblong-elliptic, drooping from slender stalks 10-15 mm long, membranous, greenish, 15-35 mm long, strongly flattened, 1-chambered.

SourceThe Illustrated Flora of British Columbia


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.

USDA Species Characteristics

Flower Colour:
Blooming Period:
Late Spring
Fruit/Seed characteristics:
Colour: Black
Present over the Summer
Source:  The USDA


Ecological Framework for Astragalus filipes

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




Elevation (metres)
801 480 1097
Slope Gradient (%)
27 2 72

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

167 40 320
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
3 1 4
Modal Nutrient Regime
# of field plots
 species was recorded in:
Modal BEC Zone Class

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

BG(11), IDF(2), PP(9)

Habitat and Range

Dry sagebrush flats and grassy slopes in the steppe and lower montane zones; rare in SC and SE BC; S to WA, NC OR and MX.

SourceThe Illustrated Flora of British Columbia


Synonyms and Alternate Names:
Astragalus filipes var. residuus Jeps.
Astragalus macgregorii (Rydb.) Tidestr.
Astragalus stenophyllus Torr. & A. Gray
Astragalus stenophyllus var. filipes (Torr. ex A. Gray) Tidestr.