| Viburnum (Adoxaceae) is a widespread genus that consists of about 175 species (Stevens, 2002). The genus in Ecuador is found in the Andes, principally found in montane cloudy forest, at elevations of 750--3800 m.; The Latin American representatives of Viburnum have received little attention compared with the Asian, European, and North American members of the genus. This is unfortunate because Latin America is a region of high diversity of Viburnum (Donoghue, 1982). The South American species have not been revised since the work of Killip and Smith (1931). Local floras have been produced only for Peru (Killip and Macbride, 1937), Panama (D'Arcy, 1987), Pakistan (Akthter, 1986), and Iran (Khatamsaz, 1995).; Here I evaluate the status of taxa of Ecuadorian Viburnum and describe them. Then analysis of important morphological characters is provided. The study is based on field collections and herbaria material. In an effort to support the species delimitation based on morphological characteristics, additional anatomical studies of trichome morphology, stomata and leaf surface using scanning electron microscopy (SEM) were carried out.; Eight species are found in Ecuador. Two V. obtectum, and V. stipitatum, are described as new to science, and the other accepted taxa are V. divaricatum, V. hallii, V jamesonii, V. pichinchense, V. toronis, V triphyllum. They are all distributed from Colombia to Peru, except that V. divaricatumi is endemic to Ecuador. Complete synonymy, detailed descriptions of the species, key, specimen citations, discussions, illustrations, distribution maps and common names for each species are provided. |
