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

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

Introduction to Vascular Plants

© Virginia Skilton  Email the photographer   (Photo ID #1337)

E-Flora BC Static Map
Distribution of Astragalus agrestis
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.

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.

Source: The Illustrated Flora of British Columbia

USDA Species Characteristics

Flower Colour:
Blooming Period:
Fruit/Seed characteristics:
Colour: Brown
Present from Summer to Fall
Source:  The USDA

Habitat / 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.

Source: The Illustrated Flora of British Columbia


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) 431 978 1980
Slope Gradient (%) 0 8 65
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
0 177 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
1 4 6
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(17), ESSF(1), IDF(62), PP(3)


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 danicus var. dasyglottis (Fisch. ex DC.) B. Boivin
Astragalus dasyglottis Fisch. ex DC.
Astragalus goniatus Nutt.
Astragalus hypoglottis Hook.

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References