PULSE FAMILY - Leguminosae: Wild Lupine; Old Maid's Bonnets; Wild Pea; Sun Dial
Flowers--Vivid blue, very rarely pink or white, butterfly-shaped; corolla consisting of standard, wings, and keel; about 1/2 in. long, borne in a long raceme at end of stem; calyx 2-lipped, deeply toothed. Stem: Erect, branching, leafy, 1 to 2 ft. high. Leaves: Palmate, compounded of from 7 to 11 (usually 8) leaflets. Fruit: A broad, flat, very hairy pod, 1-1/2 in. long, and containing 4 or 5 seeds.
Preferred Habitat--Dry, sandy places, banks, and hillsides.
Distribution--United States east of Mississippi, and eastern Canada.
Farmers once thought that this plant preyed upon the fertility of their soil, as we see in the derivation of its name, from lupus, a wolf; whereas the lupine contents itself with sterile waste land no one should grudge it--steep, gravelly banks, railroad tracks, exposed sunny hills, where even it must often burn out under fierce sunshine did not its root penetrate to surprising depths. It spreads far and wide in thrifty colonies, reflecting the vivid color of June skies, until, as Thoreau says, "the earth is blued with it."
The lupine is another of those interesting plants which go to sleep at night. Some members of the genus erect one half of the leaf and droop the other half until it becomes a vertical instead of the horizontal star it is by day. Frequently the leaflets rotate as much as 90 degrees on their own axes. Some lupines fold their leaflets, not at night only, but during the day also there is more or less movement in the leaves. Sun dial, a popular name for the wild lupine, has reference to this peculiarity. The leaf of our species shuts downward around its stem umbrella fashion, or the leaflets are erected to prevent the chilling which comes to horizontal surfaces by radiation, some scientists think. "That the sleep movements of leaves are in some manner of high importance to the plants which exhibit them," says Darwin, "few will dispute who have observed how complex they sometimes are."