Tradescantia geniculata Jacq.

• Title

  Tradescantia geniculata Jacq.

• Authors

  Nathaniel Lord Britton, Frances W. Horne

• Scientific Name

  Tradescantia geniculata Jacq.

• Description

  Flora Borinqueña Tradescantia geniculata Cojitre White Spiderwort Family Commelinaceae Spiderwort Family Tradescantia geniculata Jacquin, Enumeratio Systematica Plantarum 18.1760. We have found no popular English names recorded for this perennial, herbaceous plant, frequent in woods and thickets in the wet or moist parts of Porto Rico, ascending to the higher elevations, and on Vieques. Spiderwort is the English name of its relative, Tradescantia virginiana, of the eastern, continental United States, a well-known, showy-flowered, garden plant in the North, which was experimentally grown at the Trujillo Plant Propagation station in 1926, but proved unadapted to the tropical climate. It grows also in Santo Domingo and Haiti, in the Lesser Antilles from Antigua southward, and widely, in continental tropical America; there is also record of its occurrence in Hawaii. The Spanish name is used also for other plants of this family. Tradescantia is a genus named by Linnaeus in memory of John Tradescant, gardener of Charles the First, who died in 1638, with Tradescantia virginiana typical; about 35 species are known, all American, and all perennial herbs, with sheathing, parallel-veined leaves, regular and perfect flowers in small, stalked clusters. There are 3, thin sepals, 3, separate, stalkless petals, and 6 stamens; the 3-celled ovary has 2 ovules in each cavity, and the style is slender. The fruit is a small, 3-celled capsule, which splits into 3 valves releasing the seeds. Tradescantia geniculata (knee-like, the stem often bent near the base), is a tender, branched herb, from 20 to 80 centimeters long, with spreading branches. The leaves vary from lance-shaped to ovate, and from 3 to 14 centimeters long, they are pointed, either smooth, or sparingly hairy on both sides, their sheaths hairy. The flowers are few together, slender-stalked, in several small clusters; the sepals are lance-shaped, from 2.5 to about 3 millimeters long, pointed, smooth, or somewhat hairy; the white petals are broad and a little longer than the sepals; the stamens have hairy filaments, with anthers all alike. The capsule is 2 or 3 millimeters long, the seeds obscurely roughened, 1 millimeter long. Another species, Tradescantia elongata, grows on the banks of streams and on shaded limestone rocks in the northern and central parts of Porto Rico, in the Lesser Antilles from Guadeloupe to St. Vincent, and from Mexico to Argentina; this has creeping stems and short-stalked, pink flowers, their filaments in 2 unequal sets with dissimilar anthers, and its seeds are pitted.