Garden lupine (Lupinus polyphyllus) — identification, habitat & look-alikes

Garden lupine is a native to moist meadows and streambanks in the western United States, with hand-shaped leaves and dense spikes of pea-shaped flowers. It has escaped cultivation and can be around the Great Lakes and in parts of the Northeast. Garden lupine is also called bigleaf or large-leaved lupine.

Appearance

Appearance: This sturdy plant grows about 2–5 ft (0.6–1.5 m) tall. Dense spikes carry pea-shaped flowers that may be blue, purple, pink, or white.
Growth form: It is an upright perennial, and some forms spread from .
Leaves: Each leaf spreads like a hand, with 9–17 fingerlike leaflets, often hairy on the lower surface.
Fruit: The hairy pods turn tan to dark brown and usually hold 3–9 mottled seeds.

Look-alikes

Sundial lupineLupinus perennis

Sundial lupine usually has 7–11 leaflets and a looser flower cluster with only blue-violet flowers. Garden lupine often has 12–18 leaflets on its lower leaves and denser flower spikes that may also be pink or white.

Why they get mixed upBoth are blue-flowered perennial lupines, and both occur in parts of the eastern United States.

Where it lives

Typical habitats: moist meadows
streambanks and ditches
damp forests
roadsides
Range: It is native from the Pacific states east toward the Rocky Mountains and north into western Canada. Introduced populations occur around the Great Lakes and in parts of the Northeast.
Preferred conditions: It favors moist, generally well-drained soil in cool climates. Established plants can tolerate full sun and some seasonal dryness.
Flowering: Flowers May–Aug
Flowers May–Aug

Life cycle

Seed dispersal: Mature pods split open and release the seeds.

Growing it

Propagation: It reproduces by seed, and some forms also spread by rhizomes. Its hard-coated seeds may sprout unevenly.
Toxicity: Lupines can cause stomach upset or more serious symptoms if eaten, and the seeds of this species may poison livestock or wildlife in large amounts.

Name and classification

About the name: Russell lupines (Lupinus × regalis) are garden with this species as one parent.
Varieties and forms: This species itself can have blue, purple, pink, or white flowers.

Conservation

IUCN Red List: LCLeast ConcernLow risk of extinction
Threats: Introduced eastern populations may need local control.

Culture and stories

Culture and stories: The genus name comes from the Latin word for wolf and an old, mistaken belief that lupines robbed the soil of nutrients.

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