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)

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Distribution of Astragalus agrestis
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Species Information

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General:
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.
Leaves:
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.
Flowers:
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.
Fruits:
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:
Purple
Blooming Period:
Summer
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

Ecology

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

Minimum

Average

Maximum

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
Class
C
Number of field plots
 species was recorded in:
86
Modal BEC Zone Class
IDF
All BEC Zones (# of stations/zone) species was recorded in: BG(17), ESSF(1), IDF(62), PP(3)

Climate

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