Plants of the Eloise Butler Wildflower Garden

Canadian Milk Vetch is a native erect perennial legume growing on ridged stems from 1 to 4 feet high, but that can tend to sprawl across other plants. Stems are green, without tendrils, usually branched and with fine hair.

The leaves are pinnately compound with an odd number (15 to 35) of 1 inch long oblong leaflets. Leaflets have smooth edges, sometimes with hair on the upper medium green surface and usually with short stiff hair on the underside. When young, the leaflets have a sharp pointed tip that is an extension of the main vein beyond the leaflet tip. Each leaflet has a short stalk. A pair of small long-pointed stipules are placed at the base of the main leaf stalk.

The inflorescence is a tall dense whorled raceme held above the upper leaf axils on a long stalk.

The flowers are 5-parted, about 1/2 to 3/4 inch long, with a greenish-white hairy calyx and a tubular corolla of 5 creamy to greenish-white to purplish-white lobes. In pea-like fashion, one petal (the banner) forms an upward curved upper lip to the corolla. The side margins of this petal are rolled upward. Two petals form forward projecting laterals and two form a keel beneath the laterals, within which are the ten stamens, pistil and single style. Flowers are without scent.

Seed: Pollination is by long-tongued insects. The flower spikes mature to many dark brown seed pods containing two chambers containing several small, smooth, brownish to yellow-green kidney-shaped seeds. Seeds hand planted need scarification and at least 10 days of cold stratification to break dormancy.

Habitat: Canadian Milk Vetch grows from a taproot with rhizomes and tends to colonize an area. The plant requires a sunny, moist but well drained location such as moist prairies, open woodlands, thickets and riparian areas. Plants are short-lived - 3 to 4 years. It self-seeds also.

Names: The genus Astragalus is a Greek word for some of the legumes in this group. The species canadensis, means 'of Canada' where the plant was originally typed. The author name for the plant classification, 'L.' is for Carl Linnaeus (1707-1778), Swedish botanist and the developer of the binomial nomenclature of modern taxonomy. 

Comparisons: Of the milk vetches you may encounter in Minnesota, the large dense whorled raceme of Canada Milk Vetch should distinguish this from the others where the racemes are smaller with far fewer flowers. There are other plants that have the word 'vetch' in their name that are in a different genus - such as the Vicia. Those also have smaller racemes.