Common Name: Silky Lupin

General Information

Lupinus sericeus is an erect, herbaceous perennial plant producing one to several stout stems from a taproot; it can grow 40 - 140cm tall[].
The plant is sometimes harvested from the wild for local use as a medicine and source of materials.

Known Hazards

Lupinus species in general (and especially the seeds) contain a range of bitter-tasting alkaloids such as lupine, anagyrine, sparteine and hydroxylupanine. The pharmacological effects of these alkaloids are that they block ganglionic transmission, decrease cardiac contractility and contract uterine smooth muscle[]. When ingested in moderate to large quantities they can cause symptoms such as respiratory depression and slow heartbeat, sleepiness and convulsions[].
This species is considered to be one of the more toxic[].
Several members of the genus have been used as food and in some species low-alkaloid, sweeter-tasting varieties have been developed. There are also techniques (particularly soaking and discarding the soak water) that lower the alkaloid levels. Unless it is known that the plant is low in alkaloids then caution should be applied to any ingestion of the plant[].
Fungal toxins can readily invade the crushed seed and can cause chronic illness[].

Botanical References

Range

Western and central N. America - British Colombia and Alberta, south through Oregon and South Dakota to Arizona and New Mexico

Habitat

Grasslands, sagebrush, mountain brush plant communities and in aspen and coniferous forests; at elevations from 250 - 3,050 metres[].

Properties

Medicinal Rating
Other Uses Rating
Habit	Perennial
Height	1.00 m
Growth Rate	Slow
Pollinators	Bees, Humming birds
Cultivation Status	Wild

Cultivation Details

Lupinus sericeus is found in areas where the mean annual rainfall is in the region 250 - 500mm or more[].
Members of this genus are mainly found in dry habitats, often on stony and low fertility soils[]. This species prefers a sunny position, tolerating partial shade, and is adapted to a broad range of soil textures but found most commonly on coarse textured and well drained, non-saline soils[].
Plants can be slow growing when young and may not flower until 3 - 5 years old from seed[].
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

The pounded seeds are mixed with water then strained. The resulting liquid is used to treat eye problems[].

Agroforestry Uses:

The flowers are an important source of nectar and pollen for bees[].

Other Uses

The plants are used as bedding, and are strewn on the floor of sweat houses[].

We have no specific information for this species, but the soakwater used to extract alkaloids from several edible species of lupin has been shown to be effective as a biocide[].

Propagation

Pre-soak the seed for 24 hours in warm water and then sow in early spring in a greenhouse[, ]. The seed is best sown in individual pots since the plants strongly resent root disturbance. Germination should take place within a couple of weeks. If sown in trays, then the seedlings should be potted up into individual pots as soon as they are large enough to handle. Plant out in early summer when the plants are around 15cm tall.
It should also be possible to sow the seed in situ in mid to late spring. Protect the seed from mice.
Basal cuttings, mid spring in a cold frame. Harvest the shoots when they are about 10cm long with plenty of underground stem. Pot them up in a very sandy soil in individual pots and keep them in light shade in a cold frame or greenhouse until they are rooting well. Plant them out in the summer.
Division in early spring. Difficult.
Lupin propagation is usually carried out by seed - vegetative propagation is normally only used when propagating named cultivars[].