Ochroma pyramidale (Cav. ex Lam.) Urb.

• Title

  Ochroma pyramidale (Cav. ex Lam.) Urb.

• Authors

  Nathaniel Lord Britton, Frances W. Horne

• Scientific Name

  Ochroma pyramidale (Cav. ex Lam.) Urb.

• Description

  Flora Borinqueña Ochroma pyramidale Guano Balsa Family Bombacaeae Bombax Family Bombax pyramidale Cavanilles, Dissertatic Botanica 294. 1788. 0chroma lagopus Swartz, Prodromus Flora Indiae Occidentalis 98. 1788. Ochroma pyramidale Urban, Repertorium Species Novarum, Beihefte 5: 123. 1920. Conspicuous by large, broad leaves and very large, nearly white flowers, the Balsa is of rapid growth, and its soft, nearly white wood among the lightest in weight of that of all trees, the specific gravity being only about 0.2; this wood is used for floats, rafts, stoppers, and otherwise as a substitute for cork, the tree being also called Corkwood. The bark yields tannin, and a brown fibre used in making ropes. The wool-like interior of the long fruit is used for stuffing pillows and mattresses. The tree grows nearly throughout the West Indies, except the Bahamas and the Virgin Islands, and is occasional in Porto Rico, at lower and middle elevations, usually seen only as isolated individuals. Ochroma (Greek, referring to the large, white flowers) a genus established by Swartz in 1788, has about 8 species of trees, natives of tropical America, the one here illustrated typical, and the only one in Porto Rico. Their leaves are alternate, broad, and stalked, their flowers borne at the ends of branches. The calyx is 5-lobed, and there are 5 petals; the stamens form a 5-toothed column, with many, spiral anthers; the 5-celled ovary contains many ovules, the style is grooved above, and there are 5 stigmas. The fruit is a long, angular capsule, densely woolly within, at length splitting into 5 valves. 0chroma pyramidale (referring to the fruit) may reach about 20 meters in height, the smooth trunk up to about 0.4 meter in diameter, the stout twigs, the leaf-stalks and the under sides of the leaves finely hairy. The long-stalked leaves, nearly orbicular, and from 15 to 30 centimeters broad, are continuous-margined, toothed, 3-lobed or 5-lobed, and palmately-veined. The flowers are solitary, on stout stalks; the obconic calyx is from 6 to 8 centimeters long, finely velvety, its ovate or nearly orbicular lobes about 2 centimeters broad, or narrower; the nearly white, obovate, clawed petals are about 10 centimeters long, and finely hairy. The capsule is from 15 to 30 centimeters long, and from 2 to 3 centimeters thick, the obovoid seeds immersed in the reddish wool.