Fabaceae: Astragalus canadensis
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Family Name
Fabaceae
Common Name
Canada milkvetch
Native American Name
Lakota: pȟežúta ská hú
Description
Astragalus canadensis is a rhizomatous perennial herb with erect stems growing 30-120 cm in height. The herbage is sparsely to densely covered in ax-shaped hairs. The alternate, sessile to short petiolate, compound odd-pinnate leaves are 5-35 cm long, with 11 to 35, narrow, elliptic leaflets, 1–4 cm long, with blunt to rounded tips and lanceolate stipules 5–10 mm long. The inflorescence consists of axillary spike-like racemes, 4-20 cm long, with 30 to 100 papilionaceous flowers on a peduncle of 2-10 cm. The calyx tube is 4-7 mm long, with teeth 1-4 mm long. The corolla is greenish white to yellowish white, the banner 11-16 mm long, the wings are 10-14 mm long and the keel is 9-13 mm long and occasionally purple tipped. The wings and keel are narrowed at the base. The fruit are erect legumes, elliptic to cylindric in shape, and 9–15 mm long. Canada milkvetch blooms from May through August in moist prairies, along riverbanks and on open wooded hillsides in much of South Dakota.
Horticulture Notes
Seed Collection: Collect seeds when pods have turned brown and begin to split.
Germination: Seeds require cold treatment and scarification to help with water entry into the seed. Fall planting will usually provide good germination in the spring.
Vegetative propagation: Rhizomes can be divided in the spring.
Light: Full sun to light shade.
Soil: Very adaptable to many soil types as long as they are well drained.
Water: Moist to dry.
Additional Notes
Canada milk vetch can add texture to a native plant garden. The greenish flowers make an interesting addition to cut flower arrangements and are attractive to hummingbirds, butterflies, and other pollinators. Western tailed-blue and clouded sulfur butterflies will use it for feeding their caterpillars.