Socratea fusca Karsten, Flora Columb. 1: 109, t 54 (excl. /1, 9-12). 1860.
Type. Karsten sn, Venezuela, near Puerto Cabello, alt 1000 m (LE). Distribution. In cloud forests above 1000 m elevation in Sierra Nevada de Santa Marta, Colombia, and the Coastal Range in Venezuela. GUYANA. Upper Mazaruni River Basin, Merume Mountains, alt 1140 m, Tillett, Tillett & Boyan 44841 (NY). VENEZUELA. Edo Bolivar: Ptari tepui, SE-facing slopes, alt 1585-1600 m, Steyermark 60044 (F), Sierra de Lema, 80 km al suroeste de El Dorado, Steyermark 89402 (VEN); Ayan-tepui, faldas meridionalis, alt 1000-1480 m, Steyermark 94146 (U, VEN); Cerro Venamo, alt 900-1000 m, Steyermark & Dunsterville 92883 (VEN); without locality, Cardona 2100 (VEN).
Iriartea fusca is usually thought to occur only in the above-mentioned area. Recently, however, several probably conspecific specimens were collected in the Guayana Highland. The first of these collections, Steyermark 60044 (F), was described as new to science but unfortunately the specimens were not compared with I. fusca from which it apparently cannot be separated or it must be by the inflorescence-branches as well as the flowers and the fruit-cupule which are somewhat larger in the last-named. As this character does not seem to warrant a specific separation the Guayana Highland specimens are tentatively placed under I. fusca. The formal reduction of Dictyocaryum (Dahlgrenia) ptariense remains to be done when more field-observations of these tall palms become available.