Common Name: Sundial Lupine

General Information

Lupinus perennis is a stout, herbaceous perennial plant with erect stems growing from a thick, deep taproot; it can grow up to 70cm tall[].
The plant is harvested from the wild for local use as a food. It has occasionally been grown as a green manure and is 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[].
Alkaloid levels can vary greatly from species to species, and several members of the genus are used for food. 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

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Range

Southern and eastern N. America - Ontario to Maine, south to Texas and Florida.

Habitat

Grassy places in dry sandy soils[]. Dry, open woods and clearings, Pine Barrens and sandy prairies[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Perennial
Height	0.60 m
Pollinators	Bees
Self-fertile	Yes
Cultivation Status	Ornamental, Wild

Cultivation Details

Lupinus perennis is a very cold-hardy plant, able to tolerate temperatures down to around -25°c when fully dormant[].
An easily grown plant, succeeding in any moderately good soil in a sunny position[]. Grows well in a poor sandy soil[]. Requires an acid to neutral soil[].
It usually takes 2 - 3 years from seed before the plant starts flowering[].
This species is very susceptible to slug damage.
Lupinus perennis is the only food plant for the larvae of the Karner Blue butterfly (Lycaeides melissa samuelis). Both fire suppression and habitat loss have contributed to the decline of the lupine and the butterfly. The Karner Blue is nearly extinct over much of its range[].
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

Seed - cooked[]. Used as a protein-rich vegetable or savoury dish in any of the ways that cooked beans are used, they can also be roasted or ground into a powder. The seed has a bitter flavour due to the presence of toxic alkaloids, it should be thoroughly leached before being cooked[, ].

Seedpods - cooked[]. The seedpods are around 5cm long and 1cm wide, containing around 4 - 6 seeds[].

Medicinal

A cold tea made from the leaves has been used to treat nausea and internal haemorrhages[, ].

Agroforestry Uses:

The plant has at times been used as a green manure[].

Other Uses

The water used to leach alkaloids from the seeds of bitter forms of this plant is rich in alkaloids and can be used as an insecticide[].

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[].