Monographs Details: Martiusia laurifolia (Poir.) Britton
Authority: Britton, Nathaniel L. Flora Borinqueña.
Description:Species Description - This nearly upright, herbaceous plant, with deep, woody roots, inhabits sandy soil on the northern coastal plain of Porto Rico, where we have observed it from Santurce westward to the vicinity of Vega Baja, it may range farther west, being not very conspicuous, except when in bloom. In the West Indies it grows also in Cuba and Trinidad, and in South America in Venezuela and Brazil, we have found no Spanish name recorded. For an account of the genus we refer to our description of Martiusia rubiginosa in this work. Martiusia differs from Clitoria, with which it has been united by some students, by having leaves with only 3 leaflets, and swollen pods with ridged or crested valves; Clitoria species are natives of the Old World, the Martiusias American. Martiusia laurifolia (Laurel-leaved, but the name is not definitive) usually has several, upright, hairy, unbranched stems from 0.2 to 0.6 meters high, but sometimes a single, prostrate stem with upright branches. The pointed stipules are from 4 to 6 millimeters long, the leaf-stalks only about 6 millimeters long, or shorter; the 3, oblong, rather thin leaflets are from 3 to 10 centimeters long, blunt, notched, or pointed, smooth on the upper surface, hairy and pale green beneath. The flowers are solitary, or 2 together, on stalks from 0.5 to 3 centimeters long, subtended by small, ovate bracts; the calyx is from 2 to 3 centimeters long, smooth or sparingly hairy, its lobes about one-third as long as its tube; the corolla is 5 or 6 centimeters long, the standard petal purple, or sometimes nearly white. The pod is from 2.5 to 4 centimeters long, about 8 millimeters thick, smooth, its valves strongly ridged, the seeds about 3 millimeters long.

Discussion:Purple Martiusia Pea Family Clitoria laurifolia Poiret, in Lamarck, Encyclopédie Méthodigue Botanique Supplement 2: 201. 1918. Centrosema laurifolia Stahl, Estudios sobre la Flora de Puerto Rico 3: 64. 1885. Martiusia laurifolia Britton, Britton & Wilson, Scientific Survey of Porto Rico and the Virgin Islands 5: 412. 1924.