Euceraea rheophytica is newly described and illustrated. It differs from th
e two other species in the genus, E. nitida and E. sleumeriana in its much
smaller and narrower leaves and in its smaller, spicate (vs. branched) infl
orescences. It is known only from frequently flash-hooded riverbanks in the
large, central canyon of the Sierra de la Neblina massif in southernmost V
enezuela.