Calotropis procera (Aiton) W. T. Aiton

• Title

  Calotropis procera (Aiton) W. T. Aiton

• Authors

  Nathaniel Lord Britton, Frances W. Horne

• Scientific Name

  Calotropis procera (Aiton) W.T.Aiton

• Description

  Flora Borinqueña Calotropis procera Algodon de seda Giant Milkweed Family Asclepiadaceae Milkweed Family Asclepias procera Aiton, Hortus Kewensis 1: 305. 1789. Calotropis procera Robert Brown, in Aiton, Hortus Kewensis, edition 2: 78. 1811. Really a tree, but with the aspect of a gigantic herb, this large-leaved plant of the Old World tropics has become widely naturalized in tropical America, and is locally plentiful in Porto Rico, especially in the dry districts, growing on hillsides, in fields, and waste grounds, and also on Vieques Island, its clustered, rather large, white flowers, tinged with violet, and its large, swollen pods, are conspicuous. Mudar is another popular name; also Mata de seda. Calotropis (Greek, beautiful keel) a genus established by the eminent English botanist Robert Brown in 1811, has only three species, natives of the Old World tropics, the one here illustrated typical. They are shrubs, or trees, with broad, opposite, nearly stalkless leaves, the flowers in terminal and axillary clusters. The calyx is 5-parted, and has glands at the base within; the nearly flat corolla is cleft; there is a corona of 5 fleshy scales, which are lobed, or toothed, and short-spurred; the stamens, borne at the base of the corolla, have their filaments united into a short tube, their anthers tipped by a membrane; there are 2, short styles, connected by the disk-like stigma. The fruit is a pair of thick pods (follicles), containing many seeds appendaged by a tuft of cotton-like hairs. Calotropis procera (advancing) is from 1 to 5 meters high, with stout stems and branches. The elliptic to obovate, or nearly orbicular, rather thick leaves are from 8 to 20 centimeters long, white-felted when young, green when old, usually tipped, and with a heart-shaped base, the stout stalk only about 1 centimeter long, or shorter. The flowers are several or many together in stalked clusters from 5 to 8 centimeters broad, the individual ones on stalks from 1 to 3 centimeters long; the ovate calyx-segments are about 4 millimeters long, the corolla about 2.5 centimeters broad. The swollen pods are about 8 centimeters long, or shorter.