Bidens reptans (L.) Don

• Title

  Bidens reptans (L.) Don

• Authors

  Nathaniel Lord Britton, Frances W. Horne

• Scientific Name

  Bidens reptans (L.) G.Don

• Description

  Flora Borinqueña Bidens reptans Yellow Climbing Bidens Family Carduaceae Thistle Family Coreopsis reptans Linnaeus, Systema Naturae, edition 10. 1228. 1759. Bidens coreopsidis De Candolle, Prodromus 5; 599. 1836. Bidens reptans G. Don; Sweet, Hortus Britanicus, edition 3. 360.1839. Growing on banks, in woodlands and thickets, from lower to higher elevations, in wet and moist parts of Porto Rico, the yellow, often numerous flowers of this slender vine are conspicuous and attractive, but we have learned of neither Spanish nor English popular names for it. The highest altitude at which we have observed the plant is about 600 meters in the vicinity of Aibonito. The geographic distribution of the species is in Jamaica, Cuba, in the Lesser Antilles from Antigua to St. Vincent, and, on the continent from southern Mexico to Guatemala. Bidens (Latin, 2-toothed, referring to the pappus of the schenes) is a large, cosmopolitan genus, established by Linnaeus, now understood to include over 100 species of herbaceous plants, some with yellow ray-flowers, others with white. They have opposite leaves, variously toothed, lobed, or divided, and mostly large heads of both tubular and radiate flowers, or rays are sometimes wanting. The bell-shaped, or hemispheric involucre is composed of 2 series of bracts; the central (disc) flowers are tubular, 5-toothed, and form fruits, the marginal ones (rays) are infertile. The fruits (schenes) are various, flat, 4-sided, or nearly round, and bear from 2 to 6, barbed or hispid bristles, or teeth (awns). Bidens reptans (crawling) is a smooth, or sparingly hairy vine, which may become 5 meters long, or longer. Its leaves are slender-stalked, and vary from lance-shaped or ovate, and merely toothed, to compound, with 3, or rarely 5, toothed leaflets from 3 to 7 centimeters long, usually long-pointed. The heads of flowers are stalked, and few or several in clusters; the involucre is about 7 millimeters long, its outer bracts narrow, recurving; the bright yellow ray-flowers are blunt, and from 10 to 17 millimeters long. The narrow schenes, from 6 to 10 millimeters long, bear 2 or 3, downwardly barbed pappus-bristles. Bidens pilosa, a common white-flowered weed, is also illustrated in this work, and 2 other species of the genus grow in Porto Rico.