Abstract: | A new species, Zygia nubigena Ståhl, L. Rico & G. P. Lewis (Leguminosae–Mimosoideae), is described from western Ecuador. It is characterized by large and very thick‐walled fruits with coarsely alveolate‐reticulate surfaces, spicate inflorescences, one (less common) or two pairs of pinnae per leaf and 4 or 5 pairs of petiolulate leaflets per pinna. In leaf features, Z. nubigena is similar to Z. steyermarkii (Schery) Barneby & J. W. Grimes from montane forest in southern Ecuador, but differs by having somewhat smaller flowers borne in long, many‐flowered racemes (not 25–30‐flowered capitulae). The fruits of Z. nubigena resemble those of Z. rhytidocarpa L. Rico (Honduras, Guatemala) and Z. megistocarpa (Barbosa) L. Rico (northern Peru), but Z. nubigena differs from both in vegetative and floral characters. |