Common Name: Silvery Lupin

General Information

Lupinus argenteus is an erect, perennial plant producing a cluster of stems that are branched above; it can grow around 30 - 60cm tall[, ].
The plant is harvested from the wild for local use as a medicine. It is sometimes grown as an ornamental in gardens.

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 to Saskatchewan, south to California, New Mexico and Texas

Habitat

Dry flats and slopes in sagebrush scrub, juniper woodland and yellow pine forest; at elevations from 1,200 - 1,500 metres[].

Properties

Medicinal Rating
Habit	Perennial
Height	0.50 m
Pollinators	Bees, Insects
Cultivation Status	Ornamental, Wild

Cultivation Details

Lupinus argenteus is a very cold-hardy plant, able to tolerate temperatures down to around -30°c when fully dormant[].
Members of this genus are mainly found in dry habitats, often on stony and low fertility soils[]. In cultivation they generally grow well if given a sunny position in a deep, well-drained, moderately fertile soil with a neutral to slightly acid pH[].
A very variable species, as can be seen from the long list of synonyms.
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

A poultice of the crushed leaves is used as a treatment for poison ivy (Toxicodendron radicans) blisters[]. (As Lupinus ingratus) A cold infusion of the leaves is used as a wash

The leaves are used as an emetic, mainly for ceremonial purposes[]. (As Lupinus aduncus)

Other Uses

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[].