Common Name: Silky Locoweed

General Information

Oxytropis sericea is a clump-forming herbaceous perennial plant growing 15 - 30cm tall from a deep, many headed caudex[].
The plant is harvested from the wild for local use as a medicine.

Known Hazards

This species contains the indolizidine alkaloid 'swainsonine'. Chronic intoxication with this alkaloid causes a variety of neurological disorders in grazing animals along with reduced appetite which can lead to weight loss and cessation of reproductive ability. Swainsonine has also been found to have potential for use in anti-cancer drug treatments.
In some species, other alkaloids are suspected of causing toxicity.
In addition, some members of the genus have been reported to accumulate selenium - although this is an essential trace element it can be toxic in higher doses. Signs and symptoms of selenium toxicity include a garlic odour on the breath, gastrointestinal disorders, hair loss, sloughing of nails, fatigue, irritability, and neurological damage - in extreme cases it can result in death.

Botanical References

Range

Western N. America - Oregon to Montana and South Dakota, south through Nevada and Nebraska to New Mexico and Texas

Habitat

Open, well-drained slopes, and grassy subalpine openings bordered by open wooded hillsides or coniferous forests. It is infrequent to common on prairie uplands, streambanks, valleys, and alpine sites[].

Properties

Medicinal Rating
Habit	Perennial
Height	0.25 m
Pollinators	Bees
Self-fertile	No
Cultivation Status	Wild

Cultivation Details

Oxytropis sericea is a very cold-hardy plant, able to tolerate temperatures down to around -35°c when fully dormant[]. It is also tolerant of freezing temperatures even during the growing season[].
Oxytropis species generally grow best in a very sunny position in a deep, well-drained, sandy or gritty soil[]. This species is found in the wild on sandy, gravelly, or rocky soils but grows best on sandy loams. It is tolerant of moderately saline soils and low nutrient conditions but does not tolerate water-saturated soils such as heavy clay. It is drought tolerant but is not tolerant of excessive shade. It competes well on nutrient-rich, deep loam on subalpine sites[]. Plants are very tolerant of strong, cold winds[]. Species with woolly leaves greatly resent winter wet[200[.
Many species in this genus are suitable as ornamentals, valued for their clusters of flowers and their attractive foliage. However, species often fail in cultivation, often because of a lack of an appropriate Rhizobium bacterium[].
Members of this genus are generally resentful of root disturbance and, if the seed is not sown in situ, then seedlings need to be planted into their permanent positions as soon as possible[].
This species has a symbiotic relationship with certain soil bacteria; these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby[].

Edible Uses

None known

Medicinal

An infusion of the leaves is applied topically to sores and is also used to treat ear troubles[].

The chewed seeds are used to treat mild burns (as part of a traditional children's game)[].

Agroforestry Uses:

The plant is an important native colonizer following disturbance on western rangelands in N. America. It also occurs in climax meadow and sagebrush steppe communities[].

Other Uses

None known

Propagation

Pre-soak the seed for 24 hours in warm water and then sow in a greenhouse in early spring. Prick out the seedlings into individual pots as soon as the cotyledons emerge in order to avoid damage to the root. Grow them on in deep pots in a cold greenhouse or cold frame, and plant them out the following spring[].
Seeds have hard, impermeable seed coats and remain viable in the soil for many years[].