E-Flora BC: Electronic Atlas of the Flora of British Columbia

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

Introduction to Vascular Plants

© Virginia Skilton  Email the photographer   (Photo ID #16025)

E-Flora BC Static Map
Distribution of Astragalus filipes
Click here to view our interactive map and legend
Details about map content are available here
Click on the map dots to view record details.

Species Information

Click on the image below to view an expanded illustration for this species.

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.

Source: The Illustrated Flora of British Columbia

USDA Species Characteristics

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

Habitat / 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.

Source: The Illustrated Flora of British Columbia


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) 480 801 1097
Slope Gradient (%) 2 27 72
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
40 167 320
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
1 3 4
Modal Nutrient Regime
Number 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)


The climate type for this species, as reported in the: "British Columbia plant species codes and selected attributes. Version 6 Database" (Meidinger et al. 2008), is not evaluated, unknown or variable.

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.

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References