Monographs Details: Guilandina crista (L.) Small
Authority: Britton, Nathaniel L. Flora Borinqueña.
Description:Species Description - Characteristically growing only on coastal sands and sand dunes, and sometimes forming thickets difficult to penetrate, this prickly, woody vine is common along the shores of Porto Rico, as also on those of the small islands Mona, Culebra and Vieques, ranges throughout the West Indies, north to Florida and Bermuda, and occurs on the continent from northern Mexico to Colombia and Brazil. Guilandina, a Linnaean genus of 17 known species commemorates Melchior Guilandinus, a German traveller and botanist, who died in 1590. They are woody vines, with large, stalked, twice compound leaves, mostly aimed with recurved prickles, but some species are unarmed. The yellow, bracted, nearly regular flowers form clusters in the upper leaf-axils; there are 5 calyx-lobes, and 5, spreading petals; the 10, separate stamens have hairy filaments; the ovary is nearly stalkless, containing few ovules, the style slender. The pod is oval, or oblong, more or less compressed, prickly or unarmed, rather firm in texture, and splits into 2 valves, releasing the few, large, hard, scarcely flattened seeds, which are of different colors in the different species. Guilandina crista (crested), is a vine about 6 meters long, or shorter, its branches, leaves and pods armed with curved prickles, the twigs also bristly-hairy. The leaves are from 0.5 to 0.8 meters long, and usually have a pair of large, thin stipules, from 2 to 5 centimeters long, at the base of the stalk; each of the 4 to 8 pairs of primary leaf-divisions bears from 4 to 8 pairs of oblong or elliptic, thin leaflets from 2 to 7 centimeters long. The flowers are numerous in slender, hairy clusters from 10 to 30 centimeters long, their narrow bracts reflexed, or spreading, early falling away; the stalks of the individual flowers are from 5 to 10 millimeters long, the calyx-lobes about 8 millimeters long, the petals about 10 millimeters long. The usually densely prickly pod is from 5 to 10 centimeters long, the gray, shining seeds about 2 centimeters long. Four other species of Guilandina grow in Porto Rico or on the small islands Mona and Culebra; two of these have yellow seeds, the other two have black or dark brown seeds.

Discussion:Mato de playa Gray Nickers Senna Family Caesalpinia crista Linnaeus, Species Plantarum 380. 1755. Guilandina crista Small, Flora of the Southeastern United States 591.1903.