Monographs Details: Ghinia spinosa (Sw.) Britton & P.Wilson
Authority: Britton, Nathaniel L. Flora Borinqueña.
Description:Species Description - Diverse in aspect from other plants of the Verbena Family, but similar to them in floral structure, this low, sparingly leafy shrub is restricted in distribution to the very dry southwestern parts of Porto Rico, growing in rocky thickets, and on hillsides at low elevations; while not common, it is locally plentiful, as on the limestone hills at Salinas de Guanica, and Salinas de Boqueron. The only other place it is known from is the island Antigua, in the Lesser Antilles, as recorded by Swartz in 1788, we have found no English name for it.
Ghinia (commemorating L. Ghini, 1500-1556 an Italian botanist and physician) is a genus established by Schreber in 1789; it had previously been described under the name Tamonea by Aublet in the second volume of his "Histio[i]re des Plantes de Guiane Francaise", but inadvertedly, for in the first printing of the first volume of the same work he had already published this same name for a very different genus of the Melastoma Family. Ghinia consists of 4 or 5 species of herbs or small shrubs, natives of tropical America; they have opposite, toothed or incised leaves, and small, nearly regular flowers in long, slender clusters. The calyx is 5-ribbed, the ribs projecting as minute teeth; the corolla has a nearly cylindric tube and a spreading, 5-cleft limb; there are 4, short stamens in 2 pairs; the ovary is nearly completely 4-celled, with 1 ovule in each cavity, the style short. The fruit is small, hard, 4-celled, mostly 4-horned, usually containing 4 seeds.
Ghinia spinosa is much-branched, about 0.6 meter high, or lower, its slender branches and its few leaves finely rough-hairy. The lower leaves, not always found, are oblong, nearly stalkless, only about 1 centimeter long, or shorter, deeply incised, the lobes blunt, or rounded; the upper leaves are narrower and often longer, from 1.5 to 2.5 centimeters long, and without teeth or few-toothed. The flowers are distant from each other in slender clusters from 3 to 12 centimeters long, on very short stalks, subtended by a minute bract; the calyx is tubular in flower and about 4 millimeters long, but becomes obconic in fruit; the corolla is lavender, or nearly white, about 12 millimeters broad, its tube short. The peculiar fruit is hard, shining, smooth, with horns from 2 to 4 millimeters long.
Our illustration was first published in "Addisonia", plate 547, May, 1932.
Tamonea spinosa Swartz, Prodromus Descriptionum Vegetabllium 94.1788.
Ghinia verbenacea Swartz, Flora Indiae Occidentalis 1089. 1800.
Ghinia spinosa Britton & Wilson, Scientific Survey of Porto Rico and the Virgin Islands & 139. 1925.