This paper, in effect constituting a revision of the genus Klainedoxa, is a byproduct of ecological studies of tropical forest diversity carried out at the CENAREST laboratory near Makokou, Gabon in 1981. Collections from the rain forest canopy included at least 69 taxa new to the field station, a number new to Gabon, and several apparently undescribed species. In the case of Klainedoxa, as wellknown but taxonomically difficult genus of large trees, these collections indicate a clear resolution of the heretofore problematical taxonomic relationships. Canopy trees and lianas of the tropical rain forest are notoriously poorly understood taxonomically, in large part because the difficulty of collecting them has led to a dearth of herbarium material. New techniques for collecting canopy plants, which have recently been developed in Amazonia but little used elsewhere, were critical to the study reported here. Collections of canopy trees and lianas at Makokou were made by using a tree-climbing bicycle (Forestry Suppliers cat. no. 27170) to reach the canopy and a lightweight set of aluminum tree trimming poles (available from the Missouri Botanical Garden) to reach flowering or fruiting outer branches. A similar technique using a movable platform to climb into the canopy has previously been used successfully to collect specimens of large trees at Makokou (Hladik & Halle, 1973, pl. 3). However, the system employing a tree bicycle (which can climb trees up to 65 cm in diameter) and telescoping tree-trimming pole (potentially 12 m long) is both much more flexible and less physically demanding. Another relevant problem arises when taxonomic work, as has often been the case for tropical plants, is restricted to the herbarium with little communication between systematists and the foresters, ecologists, or native peoples who may know plants in the field and be well aware of obvious differences in characters such as those of large fruits that are rarely preserved in the herbarium. As a rule, and within a single geographic area, one who knows plant populations intimately in the field, no matter what his training, is likely to be able to evaluate what constitutes a species better than the most eminent herbarium taxonomist. The work reported here draws heavily on the field experience of the team of vertebrate ecologists working at the Makokou laboratory. Klainedoxa, a small genus of tropical African canopy and emergent trees with large elephantdispersed fruits, epitomizes these problems. Recent treatments (Aubreville, 1962; Gilbert, 1958) of the genus, variously treated as belonging to Irvingiaceae or to Simaroubaceae, have recognized two species, K. gabonensis Pierre ex Engl. and K. busgendi Engl., the latter differentiated by its generally larger, more cordate leaves. The Flora of West Tropical (Hutchinson & Dalziel, 1958) recognized, in addition to the widespread K. gabonensis, an unnamed Klainedoxa designated as imperfectly known. Since K. busgenii proves to be no more than an extreme form of variable K. gabonensis (Letouzey, pers. comm.), Klainedoxa, as currently understood, would seem to contain only a single highly variable species. The forest surrounding the field station at Makokou, Gabon is one of the best known areas of tropical Africa floristically (Halle, 1964, 1965; Halle & Le Thomas, 1967, 1970; Hladik & Halle, 1973; Florence & Hladik, 1980). Nevertheless, only a single species of Klainedoxa has been reported to occur at the field station (Halle & Le I I thank Drs. A. Hladik, R. Letouzey, P. Raven, and L. Emmons for reviewing the manuscript; Dr. Emmons for originally pointing out to me the three different Klainedoxa fruit types; and Paul Posso and the Institut de Recherche sur L'Ecologie Tropicale (CENAREST) for making possible my field work in Gabon. This research was supported by grants from the Explorers Club and National Geographic Society. 2 Missouri Botanical Garden, P.O. Box 299, St. Louis, Missouri 63166. ANN. MISSOURI BOT. GARD. 71: 166-168. 1984. This content downloaded from 207.46.13.43 on Wed, 25 May 2016 05:13:46 UTC All use subject to http://about.jstor.org/terms 19841 GENTRY-KL4 ItED)O .D 4 AT MAKOKOU. GABON 167