Commelina elegans Kunth

• Title

  Commelina elegans Kunth

• Authors

  Nathaniel Lord Britton, Frances W. Horne

• Scientific Name

  Commelina elegans Kunth

• Description

  Flora Borinqueña Commelina elegans Cojitro azul French-weed Family Commelinaceae Spiderwort Family Commelina elegans Humboldt, Humboldt, Bonpland and Kunth, Nova Genera et Species Plantarum 1: 259. 1816. First known to botanists from river banks in Colombia, this low herbaceous plant, with attractive blue flowers, has a wide distribution in tropical and warm temperate America, north to Bermuda and Florida; it is frequent at lower and middle elevations in Porto Rico, in moist and dry districts, also inhabiting the small islands Desecheo, Mona, and Vieques, growing on banks, in fields, and in woodlands. Day-flower is another name used for this plant and its relatives. Commelina, commemorates Kasper Commelin, a Dutch botanist, who lived from 1667 to 1721. The name was accepted by Linnaeus from the writings of the earlier French botanist Plumier. About 90 species are known, natives of tropical and temperate regions both of the Old World and the New. They are somewhat fleshy herbs, with stalkless, or short-stalked leaves, and irregular flowers, borne in small clusters, subtended and partly enclosed by a pair of large bracts (spathes). The flowers have 3, unequal sepals, 3 petals, 2 of them larger than the third, usually 3 unequal, perfect stamens and from 1 to 4 imperfect, smaller ones; the ovary is 3-celled, and conatins few ovules, the style simple. The fruit is a 3-celled capsule, containing 5 or 6 seeds. Commelina elegans (elegant, but the flowers vary in size) has stems which usually branch at the base, the decumbent branches sending out roots at the lower nodes. The lance-shaped or oblong, pointed leaves are from 4 to 10 centimeters long, their sheaths often sparingly fringed on the margins. The spathes subtending the flowers are pointed, hairy or smooth, united towards the base, from 1.5 to 2.5 centimeters long; the larger, blue or bluish-white petals are about as long as the spathes, or shorter. The capsule is 4 or 5 millimeters long, and contains 3, ellipsoid, smooth seeds about 3 millimeters long. Commelina longicaulis, another widely distributed species frequent in Porto Rico, has the spathes not united at the base, and oblong, reticulated seeds.