Metastelma parviflorum (Sw.) R. Br. ex Schult.

• Title

  Metastelma parviflorum (Sw.) R. Br. ex Schult.

• Authors

  Nathaniel Lord Britton, Frances W. Horne

• Scientific Name

  Metastelma parviflorum (Sw.) R.Br. ex Schult.

• Description

  Flora Borinqueña Metastelma parviflorum Metastelma Family Asclepiadaceae Milkweed Family Cynanchum parviflorum Swartz, Prodromus, Nova Genera et Species Plantarum 53. 1788. Metastelma parviflorum Robert Brown, Memoirs of the Wernerian Society 1: 52. 1809. A slender, nearly or quite smooth vine, with white, milk-like sap, small, opposite, untoothed leaves, and very small, greenish white flowers in axillary clusters; it is frequent in Porto Rico, growing in thickets at lower elevations, ranging eastward through the Virgin Islands, and southward through the Lesser Antilles. No popular names for the plant have been recorded. Metastelma (Greek, referring to the parted corona of the flower) was established a genus by the English botanist Robert Brown in 1809, with the species here illustrated typical, some 50, or more, species have been described, all natives of tropical and subtropical America. They have broad, or narrow, opposite leaves, and small, regular flowers in axillary clusters. The calyx and corolla are each 5-lobed, and there is a 5-parted corona, and 5 short stamens connivent around the stigmas; the ovary consists of 2 carpels, each containing many ovules. The fruit consists of 2, slender, smooth follicles. Metastelma parviflorum (small-flowered) may become 4 meters long, or longer. Its ovate, or lance-shaped, thin, pointed leaves are from 2 to 4 centimeters long, on slender stalks from 4 to 10 millimeters long. The flowers are few together in stalkless, or short-stalked, axillary clusters; the ovate, blunt calyx-lobes are only about 1 millimeter long; the lance-shaped, blunt corolla-segments, finely white-hairy along the inner margin, are about 2 millimeters long; the narrow lobes of the corona are somewhat dilated above. The follicles are 4 or 5 centimeters long. There are 6 other Metastelmas in Porto Rico.