Long-spurred Lupine
Lupinus arbustus Dougl. ex Lindl.
Family: Fabaceae, Pea
Genus: Lupinus
Synonyms: Lupinus laxiflorus
Other names: longspur lupine
Nomenclature: arbustus = planted with trees (habitat)
Nativity / Invasiveness: Montana native plant
Poisonous plant
No medicinal data

General: many-headed perennial with (usually) several erect to spreading, simple or sparingly branched stems 20-50 cm tall, finely short-flat-hairy and usually greenish- to somewhat grayish-flat-silky-hairy.

Leaves: alternate, the lower stalks 2-4 times, the upper ones often scarcely half as long as the blades. Leaflets 7-11, oblanceolate to narrowly oblong-oblanceolate, pointed to occasionally blunt-tipped, mostly 3-5 cm long, short-hairy on the lower surface and hairless above.

Flowers: many in clusters 7-20 cm long. Flowers 8-11 mm long, the stalks 3-7 mm long. Calyx with a spur 1-3 mm long, 2-lipped, the upper lip 2-toothed, usually less than 1/3 as long as the wings, the lower lip entire. Petals white or cream or with a tinge of bluish to purple, often varying on the same plant. Banner slightly bent back, mostly copiously short-hairy on the back to above the center. Wings usually conspicuously hairy on the upper side above the middle. Keel hairy on the upper edge most of its length. May-July.

Fruits: pods, 2-3.5 cm long, more or less silky, the seeds pinkish-brown.


Mostly in sagebrush and ponderosa pine country, in w. and s.c. parts of MT. Also e. of the Cascades, from WA to CA, ID, UT, and NV.
Poisonous Properties

Long-spurred lupine is one of several lupines that are poisonous. In the Western States livestock, especially sheep, are frequently poisoned by eating lupine seeds and pods. Losses may be especially heavy when hungry sheep are trailed through lupine ranges in late summer. Lupine hay remains toxic and has been reported to poison sheep. More common than direct toxicity, some lupine alkaloids produce birth defects in cattle if eaten during certain gestational times. Cows eating lupine during early gestation often give birth to calves with cleft palates, crooked legs and distorted/malformed spines. Poisonous species of lupine are dangerous from the time they start growth in the spring until seed pods shatter in late summer or fall. Younger plants are more toxic than older plants, however, plants in the seed stage in late summer are especially dangerous because of the high alkaloid content of the seeds and enhanced palatability in preference to dried senescent grasses. Under certain conditions and in many countries, sweet lupines are used as animal forage and seeds for human consumption.

Sub taxa:

Our specimen belong to ssp. pseudoparviflorus (Rydb.) D. Dunn.

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