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Western Wetland Flora

Field Office Guide to Plant Species

Field Milkvetch
Astragalus agrestis Dougl. ex G. Don

JPG -- Species Photo JPG -- Distribution Map

Family: Pea (Leguminosae)
Flowering: May-August
Field Marks: Of all the species of Astragalus, this species differs by its united stipules and its large flowers that are 3/4-1 inch long and crowded into ovoid heads.
Habitat: Pastures, hillsides, prairies, along roads.
Habit: Perennial herb with a taproot.
Stems: Upright, up to 15 inches tall, gray-hairy.
Leaves: Alternate, pinnately compound with 9-25 leaflets, each leaflet oblong to oblong ovate, up to 1 1/2 inches long, up to 1/3 inch wide, pointed or rounded at the tip, tapering or rounded at the base, with appressed hairs; stipules united, u
Flowers: Up to 50 crowded into ovoid heads arising from the leaf axils, the heads up to 6 inches long; flower stalks about 1/20 inch long.
Sepals: 5, united below into a tube, up to 1/2 inch long, with black and white hairs.
Petals: 5, arranged in the form of a sweet pea flower, purple to pink to blue to even whitish, up to 1 inch long.
Stamens: 10.
Pistils: Ovary superior, minutely hairy.
Fruits: Pods up to 1/2 inch long, up to 1/6 inch wide, with appressed hairs, sessile; seeds smooth, brown, up to 1/8 inch long.
Notes: The hairiness of this species is extremely variable, as is the flower color.

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U.S. Department of the Interior | U.S. Geological Survey
URL: http://www.npwrc.usgs.gov/resource/plants/florawe/species/6/astragre.htm
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Page Last Modified: Saturday, 02-Feb-2013 06:26:09 EST
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