Monographs Details: Portulaca poliosperma Urb.
Authority: Britton, Nathaniel L. Flora Borinqueña.
Description:Species Description - This pretty, annual Portulaca is characteristic of the white silica sand areas of the northern coastal plain of Porto Rico; we have observed it from Sabana Abajo, near the so-called Loiza Road, westward, locally to Manati. The type specimen was collected near Dorado. No Spanish name is known to us. Otherwise it is known to grow in Cuba, and on St. Martin and Curaçao. The attractive flowers are rose-colored in the Porto Rico plant, as portrayed by Mrs. Horne, but have been recorded as purple; perhaps they vary in color, like those of some other species, the Garden Portulaca (Portulaca grandiflora) for example.
For an account of the genus, we refer to our description of Portulaca pilosa.
Portulaca poliosperma (polished seeds) is a fleshy herb about 15 centimeters high, or lower, with ascending branches, with few, short hairs in the leaf-axils. The alternate, narrow leaves are flattened, pointed, or blunt, from 5 to 15 millimeters long, from 1.5 to 2.5 millimeters wide, commonly clustered at the ends of the branches. The flowers are encircled by short hairs, and are usually several together, but only one of a cluster expanded at the same time; the sepals are 2.5 or 3 millimeters long, the 7, or fewer, oblong, notched or blunt petals 8 to 12 millimeters long; the numerous stamens are short with yellow anthers. The ellipsoid capsule is 4 or 5 millimeters long, and opens horizontally at about the middle; the gray, tubercled seeds are 0.6 or 0.7 millimeters broad, and shining.
A small, imperfectly known plant, growing on river-rocks at El Fuerte, Coamo, and near Salinas de Cabo Rojo, was described by professor Urban as Portulaca poliosperma minor.
Our illustration was first published in "Addisonia", plate 551, May, 1932.
Portulaca poliosperma Urban, Symbolae Antillanae 4: 232. 1905.