Monographs Details: Randia aculeata L.
Authority: Maguire, Bassett. 1972. The botany of the Guayana Highland--part IX. Mem. New York Bot. Gard. 23: 1-832.
Family:Rubiaceae
Scientific Name:Randia aculeata L.
Discussion:

A great variation exists within this taxon in the arrangement as well as lack of spines, size of corollas, size of fruit, numbers of seeds within a fruit, size and shape of leaves, and pubescence of lower leaf surface. An examination of this variation shows that there are three pronounced tendencies: (1) an element of medium-sized obovate leaves, rounded at apex, attenuate into an elongated petiolar portion, in which spiny as well as spineless forms occur, and with the lower surface as well as usually the midrib beneath glabrous. This conforms to the historical type from Jamaica and is widespread in the West Indies and Central America, and reaches Tobago, Trinidad, Venezuela, and Colombia. In some specimens the main branches and lateral twigs end mainly in a pair of terminal spines, in others the spines are largely axillary and paired on the main and lateral branches, but it has not been possible to separate these variations of spine arrangements, as all types of transitions may occur in which branches with terminal spines have paired axillary spines lower down their branches. The spineless form is common in Jamaica, Cuba, and other West Indian islands. (2) A pubescent-leaved variation, in which the lower surface, lower midrib, and lateral nerves of the leaf blades have softly spreading pubescence, occurs in Venezuela and Trinidad. The leaves are short-petioled and often broadest in the middle instead of in the upper third as in the historical variation. (3) A variation with the leaves greatly reduced in size is found in many of the West Indian islands, especially the Bahamas, Bermuda, Cuba, Puerto Rico, Grenadines, St. Vincent, Dominican Republic, St. Thomas, St. Remy, St. Barths, Virgin Islands, Santo Domingo, and Turks Island. Both terminal as well as axillary spines on the branches appear within this variation. Intermediate specimens, with leaves varying from small to medium in size and transitional in measurements, bridge the gap between the smallest-leaved variations of (3) and the medium-sized leaves of the historical (1) variation.