Monographs Details: Ipomoea polyanthes Willd. ex Roem. & Schult.
Authority: Britton, Nathaniel L. Flora Borinqueña.
Description:Species Description - Usually twining on bushes, and distributed nearly throughout tropical America, the Yellow Morning-glory bears conspicuous and attractive flowers, often profusely (whence the specific name polyanthes) and in large clusters. It is a common vine of most of West Indies, ranging northward into southern Florida, but is not recorded as growing in the Bahamas; it extends northward also into western Mexico, and it also inhabits tropical parts of the Old World. In Porto Rico it occurs, for the most part, at lower elevations, on banks and in thickets. We are unaware of any attempt to cultivate it as an ornamental vine.
Ipomoea is a very large genus, some 400 species being known, widely distributed in America, Asia and Africa, most of them in tropical lands, a few in temperate regions. There are 22 species native in Port Rico. The generic name given to them by Linnaeus is Greek, meaning similar to a worm, in allusion to the sinuous stems of some of the species, most of them being trailing or twining herbaceous vines, but a few are upright herbs. They are, technically, distinguished from other genera of the family by having flowers with united styles, globose stigmas, the stamens and pistils not longer than the tube of the bell-shaped or funnelform corolla, and the fruit splitting into valves.
Ipomoea polyanthes is a slender, nearly smooth vine, sometimes becoming 5 meters long or longer. Its leaves are various in shape, from narrow to broad, or even orbicular, pointed or blunt, sometimes nearly arrow-shaped as in our illustration, and in length range arrow-shaped as in our illustration, and in length range from 4 to 9 centimeters; their stalks are slender; their surfaces smooth or finely hairy. The bright yellow flowers are borne in long-stalked clusters (umbels), each flower on a stalk from 1 to 3 centimeters long, or sometimes shorter; the sepals are oval, blunt but minutely tipped, about 8 millimeters long; the corolla is nearly funnelform with a tube about 2.5 centimeters long, the limb about as broad as the length of the tube, or somewhat broader, its margin slightly wavy; the ovary is 2-celled, the 2 styles united. The subglobose, capsular fruit is somewhat flattened vertically, about 10 millimeters in diameter, containing few or several, velvety seeds.
Our illustration was first published in "Addisonia", plate 441, December 1928.
Convolvulus umbellatus Linnaeus, Species Plantarum 155. 1753.
Ipomoea umbellata Meyer, Primitiae Florae Essequiboensis 99. 1818. Not Ipomoea umbellata Linnaeus, 1759.
Ipomoea polyanthes Roemer & Schultes, Systema Vegetabilium 4: 254. 1819.