Astragalus agrestis Douglas ex G. Don
field milk-vetch (purple milkvetch)
Fabaceae (Pea family)

Introduction to Vascular Plants


© Virginia Skilton     (Photo ID #1337)


E-Flora BC Static Map

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

Species Information

Low perennial herb from a buried stem-base and long, slender rhizomes; stems several, decumbent to erect, 10-30 cm long/tall, loosely tufted, slender, appressed-hairy with unbranched hairs.
Alternate, pinnately compound, 4-10 cm long, leaflets 11 to 23, linear-oblong to elliptic, mostly blunt to notched at the tip, 0.5-2 cm long, thinly short-hairy.
Inflorescence a dense, head-like, axillary raceme of 7 to 20 erect, pea-like flowers, the racemes 1-3 cm long and wide, on stalks from shorter to longer than the leaves; corollas usually purplish, tinged with white, drying bluish, 15-22 mm long, the narrow banner slightly longer than the wings, which are 4 mm longer than the keel; calyces bell-shaped, 8-13 mm long, hairy with mixed black and white hairs, the linear teeth 1/2 as long as the tube.
Pods, egg-shaped to oblong, unstalked, erect, 7-10 mm long, membranous, densely greyish to blackish soft-hairy, somewhat flattened, grooved beneath, 2-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:
Fruit/Seed characteristics:
Colour: Brown
Present from Summer to Fall
Source:  The USDA


Ecological Framework for Astragalus agrestis

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)
978 431 1980
Slope Gradient (%)
8 0 65

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

177 0 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
4 1 6
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(17), ESSF(1), IDF(62), PP(3)

Habitat and Range

Moist to mesic meadows, grassy slopes, streambanks, lakeshores, forest openings and occasionally on cool talus slopes in the steppe and montane zones; common in S BC east of the Coast-Cascade Mountains and S of 52degreeN, rare northward; N to YT, E to ON, and S to WI, MN, KS, NM and N CA.

SourceThe Illustrated Flora of British Columbia


Synonyms and Alternate Names:
Astragalus danicus var. dasyglottis (Fisch. ex DC.) B. Boivin
Astragalus dasyglottis Fisch. ex DC.
Astragalus goniatus Nutt.
Astragalus hypoglottis Hook.