Fabaceae : Oxytropis sericea

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Family Name

Fabaceae

Common Name

White locoweed

Description

Oxytropis sericea is an acaulescent perennial herb growing from a much-branched caudex, forming mounds of silky-haired leaves. The leaves are 4-30 cm long with 11 to 25 lanceolate to narrowly ovate leaflets, 5–40 mm long and 2-10 mm wide. The petioles are 1-15 cm long with membranous, hairy stipules, 8–22 mm long. Inflorescences are terminal racemes of 6 to 30 flowers atop of erect to ascending scapes (flowering stems), 5–30 cm long, including the peduncle. The calyx is covered in white and/or black hairs, and forms a tubular-campanulate tube, 8-12 mm long with unequal teeth 2-5 mm long. The papilionaceous corolla is white to yellowish white; the banner 16–25 mm long and deeply lobed, the wings 15-20 mm long, and the keel is 12-17 mm long with a small appendage at the distal end. The fruit are sessile, erect, oblong legumes, 15–25 mm long, with a short beak and having a few short stiff hairs to a silky covering of hair. White locoweed blooms from April into June in rocky prairies, hillsides, open woods and valleys in southwestern South Dakota.

Additional Notes

White locoweed is toxic, as the name implies it causes neurological damage to livestock that ingest it. In a native plant garden, it has attractive flowers that are frequented by bumblebees and butterflies. However, planting should not be available to animals or young children, as it can cause severe damage if ingested, and has no current treatment. For my garden, there are several Astragalus species that I would prefer.

Horticulture Notes

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Seed Collection: Collect seed in June-August when pods begin to split open, and the seeds are black.

Germination: Fall sowing is recommended. Scarification with sandpaper will allow some germination with spring planting.

Soils: Rocky or gravelly well drained soil.

Light: Full sun

Water: Dry