Samanea saman (Jacq.) Merr.

• Title

  Samanea saman (Jacq.) Merr.

• Authors

  Nathaniel Lord Britton, Frances W. Horne

• Scientific Name

  Samanea saman (Jacq.) Merr.

• Description

  Flora Borinqueña Samanea Saman Guango Rain-tree Family Mimosaceae Mimosa Family Inga Saman Willenow, Species Plantarum 4: 1024. 1806. Pithecellobium Saman Bentham, in Hooker's Journal of Botany 3;216.1844. Samanea Saman Merrill, Journal of the Washington Academy of Sciences 6: 46. 1916. Native of northern South America, this very large tree was introduced, many years ago, into other parts of tropical America and the Old World tropics, on account of its rapid growth and the immense spread of its branches, fully grown individual trees sometimes shading areas of land over 50 meters in diameter. In Porto Rico it is locally spontaneous from its seeds, and grows vigorously, not only in districts of considerable rainfall, but also where relatively dry; a tree planted some years ago at the Coamo Springs Hotel by Dr. D. W. May, Director of the Agricultural Experiment Station at Mayaguez, rapidly attained large size; here the average, annual rainfall is only about 100 centimeters. The wood is reddish, hard and heavy, but not very durable; the pods are pulpy, sweet, and supply food for cattle. Cow-bean Tree being another name; Rain-tree is with reference to the drooping and folding of its leaves in cloudy times, often preceding showers, they being sensitive to changes in light, drooping also in the evening. Other names used for it are aboriginal Saman, and Giant Thibet. It may shed its leaves and bloom more than once a year, the flowers appearing with the new crop, delicately beautiful as small, pinkish clusters among the young foliage. Samanea includes about 25 species of unarmed trees and shrubs, mostly South American, with twice compound leaves and round, stalked clusters of small flowers. The calyx is 5-toothed, the corolla 5-toothed or 5-lobed; the numerous stamens are much longer than the corolla, their filaments partly united into a tube, the anthers small; the ovary contains several or many ovules and the style is slender. The pod is flattened, mostly straight, leathery or fleshy, and splits tardily into 2 valves or falls away without opening. Samanea Saman reaches a maximum height of 20 meters or more, with a trunk over a meter in diameter, the old gray bark separating in strips, the twigs and leaves finely hairy. The leaves are large, with from 2 to 6 primary divisions, each bearing from 2 to 8 pairs of thin, oblong or obovate, blunt leaflets from 2 to 4 centimeters long; the tufts of flowers are long-stalked; each flower is short-stalked, the calyx about 6 millimeters long, the silky corolla 10 to 12 millimeters long, the stamens 4 or 5 centimeters long. The pods are from 10 to 20 centimeters long, 10 to 18 millimeters wide, about 6 millimeters thick, somewhat fleshy, the oblong seeds from 5 to 8 millimeters long.