Lupinus perennis is a native perennial forb in the legume family, commonly known as wild lupine or sundial lupine. It features a striking display of blue to purple, pea-like flowers arranged on tall, upright spikes. This plant is ecologically significant, serving as the exclusive host for the endangered Karner blue butterfly.
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Growth Habits & Characteristics
•Type: Herbaceous perennial
•Height: Typically 1 to 3 feet tall
•Spread: Forms clumps; may develop a basal rosette of leaves
•Habitat: Prefers well-drained, sandy or rocky soils; commonly found in pine barrens, prairies, and open woodlands
•Light Requirements: Full sun to partial shade
•Soil & Nutrition: Adapted to nutrient-poor soils; capable of nitrogen fixation through symbiotic root bacteria
•Bloom Time: Spring to early summer, with the vibrant flowers providing seasonal color
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Host Insects & Ecological Importance
•Karner Blue Butterfly (Lycaeides melissa samuelis):
The wild lupine is the sole larval host plant for the endangered Karner blue butterfly. The caterpillars feed on the leaves, making the plant critical for the species’ lifecycle and conservation efforts. The Karner blue is found near the Great Lakes region in portions of New Hampshire, New York, Michigan, Wisconsin, and Ohio. The main factor causing the decline of the Karner blue is loss of habitat due to suppression of wildfires and clearing land for farming, residential, and commercial purposes. These activities allow shrubs and trees to invade open areas which shade out plants like sundial lupine. In turn, this creates small, fragmented pockets of suitable habitat for both the lupine and the butterflies. 
•Pollinators:
Lupinus perennis attracts a variety of bees, butterflies, and other beneficial insects that visit the flowers for nectar, contributing to pollination and overall ecosystem health.
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Additional Ecological Benefits
•Soil Enrichment:
As a legume, wild lupine plays a role in nitrogen fixation, improving soil fertility in its native habitats.
•Habitat Restoration:
Its presence is key in prairie and pine barren restoration projects, providing essential support for a range of native wildlife.
•Biodiversity Support:
By hosting the Karner blue butterfly and attracting a diversity of pollinators, Lupinus perennis enhances local biodiversity and ecosystem resilience.