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Abstract
STEVENSON, D. W. (New York Botanical Garden, Bronx, New York 10458, USA). Chigua, a new genus in the Zamiaceae with comments on its biogeographic significance. Memoirs of The New York Botanical Garden 57: 169–172. 1990. Chigua a new genus in the Zamiaceae from Colombia is described and illustrated. This genus differs from all other cycad genera in having a prominent midrib with longitudinally dichotomous branched lateral veins in its pinnae and hexagonal sporophylls with raised mounds on the peltate face at the angles. Two species are described and illustrated: C. restrepoi sp. nov. and C. bernalii sp. nov. which differ from each other chiefly in leaflet width, length, and shape. The main biogeographic significance lies in this genus being the only endemic genus in the Cycadales for South America.
Keywords: Chigua, Zamiaceae, South American endemic
