Monographs Details: Alibertia edulis (Rich.) A.Rich. ex DC.
Authority: Maguire, Bassett. 1965. The Botany of the Guayana Highland. Mem. New York Bot. Gard. 12 (3): 1-285.
Family:Rubiaceae
Discussion:Genipa edulis L. Eich. Act. Soc. Hist. Xat. Paris 1: 107. 1792. The series involving Alibertia edulis, A. acuminata, and A. latifolia is a complex one, and A. eelulis has been variously interpreted to the extent that material so identified in herbaria includes a wide variation and assortment of specimens. So far as m y present interpretation of A. edulis goes, material previously identified from Venezuela as that species must be placed with A. latifolia and A. acuminata. Venezuelan material now placed in A. acuminata is mainly in the fruiting stage and will have to be recollected in the flowering stage with both sexes represented in order that the problem be clarifled. The main differences between A. acuminata and A. latifolia were presented in the key at the beginning of the treatment of this genus. The following paragraphs are presented to elaborate further various differences between the related taxa in the A. edulis complex. Both A. edulis and A. acuminata have the leaf-blades oblong-lanceolate, narrowed at both ends, turning dark on drying with a tendency for the tertiary venation to be prominent on the upper side, but with the lateral nerves and venation inconspicuous on the lower side. A sublustrous to lustrous effect is usually evident in A. acuminata. As contrasted with the previous presentation, A. leitifolia has leaves proportionally fewer times longer than broad with a shorter, more abrupt apex and more obtuse to rounded base of the leaf-blade, of a more ovate-oblong shape, and the leaves upon drying are greener and less dark, the tertiary venation not apparent above, but the lateral nerves are prominent below, and there is usually a greater development of pubescence on the lower side along the midrib and in the axils of the midrib and lateral nerves. In the historical type of A. edulis from British Guiana, along with other South American material, the stipule is only acute to short-acuminate and varies from usually 5-8 mm long, and is glabrous to glabrate without. In specimens from Central America, Mexico, and the West Indies identified as A. edulis, the stipule is more setaceous and elongated, prolonged to 7-18 mm long. This is especially evident in the Panamanian A. longistipulata Riley and A. panamensis Riley, in which the stipules are caudate to setaceous. The West Indian material, mainly Cuban, has mainly conspicuous stipules up to 15 mm long and longcaudate or setaceous. If the stipule character is of sufficient importance, then most of the material identified as A. edulis from Central America, Mexico, and the West Indies will have to be placed into the A. longistipidata-A. panamensis alliance. Most of the South American material (including specimens cited by Cuatrecasas as typical A. edulis) of typical A. eelulis with the shorter tipped stipules agrees with Richard's description of A. edulis. The acute character of the stipule is also shown in Richard's plate illustrating A. edidis. In A. latifolia and A. acuminata the stipule, as in typical A. edulis from South America, is, likewise, short, acute to subacuminate, broadly ovate to deltoid, and 2-13 mm long, becoming larger in A. latifolia than in A. acuminata. The fruit is apparently more depressed in typical A. edulis from South America than in either A. acuminata or A. latifolia, in which the fruit is globose. It appears to be larger in typical A. edulis than in A. acumineita or A. latifolia. The corolla of the staminate flowers in A. eelulis is longer and broader than that of either A. acuminata or A. latifolia. The pubescence on the outer surface of the staminate corolla in A. latifolia is more densely sericeous or buff-strigose than in A. edulis or A. acuminata. In the two latter species the hairs are shorter and gray, presenting a cinereous-pulverulent surface. The calyx of the staminate flowers presents differences also. In typical A. edulis of South America, as well as in material from Central America, Mexico, and the West Indies, the calyx is provided with teeth up to 1-2 mm. In A. latifolia the calyx of the staminate flowers is usually truncate with little or no development of any teeth, and the same is true in the staminate calyx of A. acuminata. In the pistillate calyx of typical .1. edulis from South America the teeth are less than 1 m m , being less conspicuous than in the calyx of the staminate flowers. In the pistillate calyx of A. latifolia the calyx, as in the staminate flowers, is also ti-uncate and either without teeth or only faintly lobate. The size of the calyx is similar in both A. edulis and A. latifolia, but in A. acuminata is much shorter. The isotype of Alihertia edulis which I have examined at NY is a pistillate specimen with the pistillate flower solitary. The hypanthium in this specimen is sparsely appressed-pubescent near the base, 6 mm long and 4.5 mm broad; the calyx-tube is 5 mm long and 6.5 mm broad with 6 triangular subulate teeth arising from the truncate apex of the hypanthium, and these teeth are about 0.5 mm long and moderately short appressed-puberulent without. The broadly ovate stipules are acute, glabrous, and 5-7 mm long.