Lupine, Wild Sundial - Lupinus perennis

Lupinus perennis, also known as Wild Sundial Lupine, is a perennial wildflower native to lower Michigan. Plant reaches 2 feet tall and flowers from May to July with an intricate blue, pea-like blossom.
 
Wild Lupine prefers full sun to partial shade and its preference for medium to dry, acidic sandy soil or sandy loam makes it well suited to many UP habitats. Lupine's attractive whorls of leaves rotate during the day to track the sun, giving it its common name. In central Michigan, this is the sole host plant to the endangered Karner Blue Butterfly and one of the hosts of the rare Frosted Elfin. In the U.P. there are a number of other butterflies and moths that host on Wild Lupine and its kin, including Hairstreaks, Elfins, Blues, Duskywings, Coudywings, and Skippers. Note that the larvae of these smaller butterflies frequently form their chrysalis in the leaf litter beneath the host plant. Leave the leaves to allow them to complete their life cycle and make next year's butterflies.
 
Wild Sundial Lupine is also visited by a variety of native bees who collect pollen to feed their young. It reportedly does not produce nectar, however, ours seems to attract droves of swallowtail butterflies who have no use for pollen.
 
Caution: there is a similar plant in the UP that is invasive, Lupinus polyphyllus, Bigleaf Lupine. It is a western US plant. This invasive lupine is not used by our native bees and butterflies, specifically, it is not used as a host plant by the Karner Blue or other eastern US butterflies. Bigleaf Lupine can be roughly identified by habitat - it favors moist areas like ditches, especially in the Keweenaw and the western U.P.  Native Wild Sundial Lupine is a dry prairie plant. Bigleaf Lupine is also much taller and often is found in colors other than the bluish-purple of Wild Sundial Lupine.
 
Although characteristics overlap, Wild Sundial Lupine has 7 to 11 leaves per whorl (good), while mature Bigleaf has many more, and often appears to be a double layered whorl (bad). Bigleaf Lupine is considered invasive by the National Park Service and other federal agencies. It spreads easily, and like other invasives, displaces the native plants needed by our insects and wildlife. Bigleaf Lupine should not be cultivated or spread in Michigan and should be removed if possible. It is likely to hybridize with Wild Sundial Lupine and the resulting offspring may not be utilized as host plants by native butterflies.
 
Although they mostly leave the foliage alone, our deer seem to think the flower stalks and seeds are quite delectable. Shield the plants with native grasses (deer don't like Little Bluestem), sticks, or fencing to enjoy the blooms. To achieve the dense planting shown, plant 10 or more at 12" spacing. These are in very sandy soil in full shade (they recieve less than 3 hours of direct sunlight per day). We were concerned that the shade would affect blooming. Although they are a little more sprawling than our plants in the sun, this Wild Sundial Lupine patch flowers and seeds just fine (protected from deer).