The genus has been previously known from Amazonian Brazil and Peru, and from French and possibly British Guiana. During a study of the genus, two new species collected in the Venezuelan Guayana, one from the base of the slopes of Cerro de la Neblina, the other from the base of Chimanta Massif, form the basis for the first records of the genus in Venezuela, while two additional species, here described as new, one from Peru, the other from Brazil, have been encountered in the material examined in F, NY and US. I am grateful to the curators of these
institutions for the courtesy of studying this material.
Kotchubaea has a distribution following the Amazon, Rio Solimoes, and Rio Negro in Brazil, Amazonian Peru along the Rio Amazonas in the Dept. Loreto, thence ascending between 1200-1600 m in Peru in the drainage of the Rio Muyo (tributary of the Rio Huallago) of the Dept. San Martin, extending northward in Venezuela following a tributary of the Rio Negro, to Cerro de la Neblina and along the Rio Tirica (tributary to the Rio Caroni) to Chimanta Massif. In French Guiana it is known from low altitudes in the vicinity of Cayenne and along the Rio Maroni.
The species are found in tall forest which is not inundated, most of the species inhabiting the forests of low altitudes from slightly above sea level to 100 m. Three species are found between 600-1600 m : K. neblinensis at 600-700 m, K. longiloba at 1000 m, and K. montana at 1200-1600 m. The species are characterized by various degrees of indument on the outer surface of the corolla-tube of the staminate flowers. In K. sericantha the indument is densely sericeous with relatively elongated hairs, whereas in the other species of the genus the hairs are very short. In K . neblinensis, K . montana, K . duckei, and K. palustris only the basal 1-8.5 m m of the corolla-tube is glabrous, in K . longiloba the glabrity extends up to 17 mm of the tube, in K. semisericea the glabrity extends up the lower 25-50 mm of tube, while in K . insignis all the outer surface of the tube is glabrous.
Staminate flowers are known from all the species and are apparently the ones more commonly collected. Pistillate flowering specimens are known only from K. sericantha, K . palustris, and K. insignis. In K . sericantha the staminate flowers are fasciculate in umbelliform cymes and lack a common peduncle, whereas in the other species of the genus the pedicels of the staminate flowers are borne on a common peduncle of varying length.
The pubescence on the lower surface of the leaf-blades is best developed in the Peruvian K. montana and K . urophylla, the former ascending to an elevation of 1200-1600 m . Various degrees of puberulence of the petioles and midribs and lateral nerves of the lower leaf-surfaces are mainly encountered in K. palustris and K. sericantha. The corolla-tube is broader and the pedicels are stouter and more strongly angled in K . sericantha than in the other species of the genus.