Stegnosperma halimifolia Benth.

• Title

  Stegnosperma halimifolia Benth.

• Authors

  Nathaniel Lord Britton

• Scientific Name

  Stegnosperma halimifolium Benth.

• Description

  Flora Borinqueña Stegnosperma halimifolia Stegnosperma Family Phytolaccaceae Poke-weed Family Stegnosperma halimifolia Bentham, Botany of the Voyage of the Sulphur 17, plate 12. 1844. Stegnosperma cubense A. Richard in Sagra, Historia de la Isla de Cuba 10: 309. 1845, plate 44. 1845. This woody vine or vine-like shrub, for which we have ascertained neither Spanish nor English names, was unknown in Porto Rico until detected by professor Charles B. Horne, in January, 1931, on a steep, wooded slope about 4 kilometers southwest of Aibonito at an elevation of about 500 meters, where the average annual rainfall is, presumably, between 50 and 60 inches. It inhabits relatively dry parts of Santo Domingo, Cuba and Jamaica, and from Sonora and Lower California to El Salvador in Central America. The plant was first made known and illustrated from herbarium specimens collected in 1839 at Cape San Lucas. Lower California, during the important scientific voyage of the British ship Sulphur, surveying the coasts of western North America; specimens collected in western Cuba were described one year later as a distinct species, but comparisons of many specimens indicate that the genus is monotypic. Stegnosperma (Greek, covered seed, referring to the aril) has been classified in the Family Phytolaccaceae; it differs from typical genera of that family, however, in that the flowers have petals, and in the fruit, which splits open to release the seeds. Stegnosperma halimifolia may attain a length of 8 meters, and has been observed in Jamaica, climbing to the tops of low trees; at the locality near Aibonito, Porto Rico, it is arching, rather than climbing, but its stems are partly supported by bushes among which it grows; its long, slender branches are smooth. The leaves are alternate, pale green, elliptic, pointed, or blunt, from 2 to 5 centimeters long, short-stalked, rather faintly veined, and without teeth; the specific name halimifolia indicates their resemblance to some species of Halimium, an Old World genus of the Rock-rose Family. The stalked flowers are borne in clusters 16 centimeters long, or usually much shorter, at the ends of the branches; there are 5 oblong sepals about 4 millimeters long, and 5 white petals about 5 millimeters long; the 10 stamens have very slender filaments united into a ring at the base, and small, oblong anthers; the pistil has a 1-celled ovary, topped by from 3 to 5 styles and containing from 3 to 5 ovules. The reddish, fleshy fruit is 3-5-grooved, about 7 millimeters long, and splits when ripe into as many hard segments as there are grooves, exposing the ellipsoid seeds, which are black, shining, about 4 millimeters long, and enclosed by a fleshy aril, purple in the Porto Rico plant, but described as white in the plant of other localities. Our illustration was first published in "Addisonia", plate 550, May, 1932.