Calopogonium orthocarpum Urb.

• Title

  Calopogonium orthocarpum Urb.

• Authors

  Nathaniel Lord Britton, Frances W. Horne

• Scientific Name

  Calopogonium orthocarpum Urb.

• Description

  Flora Borinqueña Calopogonium orthocarpum Jicana Small Blue Pea Family Fabaceae Pea Family Calopogonium orthocarpum Urban, Symbolae Antillanae 1: 327. 1899. An herbaceous, climbing or trailing vine, sometimes covering considerable areas of land, Jicana is frequent at lower and middle elevations in the moist parts of Porto Rico, growing in thickets, in fields or on hillsides, occasionally invading cultivated land as a weed; it grows also in Cuba and in Santo Domingo. The genus Calopogonium was established by the French botanist Desvaux in 1826; about 8 species are now known, all natives of tropical America. Besides the one here illustrated, another, Calopogonium coeruleum, has been observed on a hillside at the Porto Rico Agricultural Experiment Station, at Mayaguez, but it is supposed to have been introduced there, and is not known to be native in Porto Rico. The generic name is Greek, signifying beautiful beard, with reference to the long-hairy pods of some of the species. They are herbaceous, twining vines, sometimes woody toward the base, with 3-foliolate leaves, and small, blue or violet flowers in small clusters, each flower short-stalked; the calyx is 2-lobed, the upper lobe with 2 teeth, the lower one with 3; the largest petal (standard) is broad, the lateral ones (wings) narrow, the keel blunt; nine of the stamens are united by their filaments, the tenth one is separate; the ovary contains several or many ovules; the style is smooth. The narrow, flat pods split longitudinally when ripe, releasing the orbicular seeds. Calopogonium orthocarpum is a long-hairy vine, becoming a meter long or longer. The 3 leaflets of each leaf are broad, from 2.5 to 10 centimeters long, and finely hairy, the 2 lateral ones oblique. There are several flowers in each cluster, the clusters borne on stalks which are sometimes longer than the leaves, but often much shorter; the calyx is from 6 to 8 millimeters long, and the blue corolla is about as long. The pods are very narrow, straight (whence the specific name orthocarpum) long-hairy, impressed between the several seeds, from 3 to 3.5 centimeters long and only 4 millimeters wide.