Lupine, the common name of plants of the genus lupinus. There is some doubt as to the origin of the name, but most authors regard it as coming from lupus, a wolf, and as having reference to the voracity of the plants in devouring the fertility of the soil. The genus belongs to the papilionaceous suborder of the great family of leguminosae, and contains about 80 species, some 56 of which are North American; the remainder are South American, with a few in the Mediterranean region. The country between the Rocky mountains and the Pacific is so rich in these plants as to be known to botanists as the lupine region. The species are herbs or half-shrubby plants, and comprise both annuals and perennials, with simple or digitately compound leaves, and flowers mostly in terminal racemes; the flowers are usually showy, mostly blue, though some are white, yellow, and variegated; the stamens are united into a tube by their filaments; the pod flattened, with thick valves, and often constricted between the rather large seeds. One species, the common wild lupine (L. perennis), is found from Canada to Florida, and as far west as the valley of the Platte; it is common in sandy soils, and is sometimes found in such abundance as to exclude almost all other vegetation.
Its stem is erect and somewhat hairy; its leaves are digitate, consisting of from eight to ten lanceolate wedge-shaped leaflets, arranged around the end of the petiole; its flowers, on a terminal spike, are blue, or sometimes rose-colored, and specimens have been found with pure white flowers. The root is perennial, and throws up each successive season increasing flowering stems; it grows readily from the seeds. A natural patch of these charming plants overspreading a large area of sand, clothing the barren waste with beauty, cannot fail to attract the eye. Artificially propagated, the wild lupine succeeds best when raised from seeds, and in such cases blossoms in the second or third year. The other eastern species are L. villosus and L. dif-fusus, both perennials with simple and very silky leaves; these are not found north of Georgia and North Carolina. The most widely known species of the Pacific coast is the many-leaved lupine (L. polyphyllus), as that has long been in cultivation as a showy garden plant; its stems grow 2 to 5 ft. high; the long-petioled leaves have 10 or more leaflets, and the raceme, 1 to 2 ft. long, is covered with blue or purple flowers; in some instances the flowers are white.
Large, well established clumps of this are exceedingly beautiful; it is readily raised from seed, but the plants should be set where they are to bloom when quite young, as large specimens are apt to die when transplanted; this is sometimes found in gardens under the name of L. macrophyllus. Among the yellow-flowered species of the western coast are L. arboreus, L. sulphureus, etc.; and among the white-flowered ones, L. densiflorus is sometimes seen in gardens. L. arboreus often reaches the height of 10 ft. and forms a large bush, which is quite shrubby at base; while an annual species (L. uncialh), recently described by Mr. Watson, is less than an inch high. - Some of the exotic lupines in cultivation are the yellow lupine from Europe (L. luteus); the hairy lupine (L. hirsutus), with very hairy leaves and pods, and flowers blue, rose color, or white; and the white lupine (L. albus), which has its leaves smooth above and hairy beneath, and smooth pods. The last named species grows spontaneously in the Mediterranean region, and was formerly used as pulse; it is now employed in continental Europe as a green manure, the crop being ploughed under for the purpose of enriching the soil, in the same manner that our farmers use clover and buckwheat, a practice mentioned by Columella and other early writers on agriculture; the seeds of this species, as well as those of L. tennis, are sparingly used as food by Egyptians and Arabs; the seeds are fed to poultry, and the young tops of the plants are eaten by cattle. - Perhaps the most important economical use of the lupines is one recently determined by the experiments of the San Francisco park commission.
Much of the land directly upon the coast consists of shifting sands; deep cuttings disclosed the fact that the roots of some species of lupine penetrated to the depth of 20 ft., and suggested the idea that these plants might be made useful in binding the loose sands; barley, which germinates more rapidly than the lupine seed, was sown to protect the lupines while very young, and this held the sands until the slower-growing plants became established; the species of lupine selected were L. arboreus and L. albi-frons, which grow naturally in such situations. In a single year the lupines covered the sands with a dense vegetation 2 to 3 ft. high, sufficient to prevent them from shifting during the severest storms, and to allow of the growth of various maritime pines, willows, and other trees, as well as such grasses as flourish in sandy localities. - A revision of the genus lupinus, by Sereno Watson, is to be found in the "Proceedings of the American Academy of Arts and Sciences," vol. viii. (May 13, 1873).
Many-leaved Lupine (Lupinus polyphyllus).