A CONTRIBUTION TO THE GENERIC DELIMITATION OF SECHIUM (CUCURBITACEAE,SICYINAE)

The generic limits of Sechium continue to be controversial. A phenetic analysis of the species of Sechium and its allies in subtribe Sicyina e, using both palynological and macromorphological characters, was car ried out. The results of the analysis basically support the taxonomic circumscription of this genus proposed by Jeffrey (1978). Both cluster and ordination analyses showed that ail the species recognized by Jef frey as pertaining to the genus Sechium as well as others more recentl y described, form a well defined group constituted by 11 species and c learly separated from other taxa in the subtribe Sicyinae. The observe d clustering within Sechium does not correspond to the two sections of the genus recognized by Jeffrey. Sechiopsis appears to be the closest relative of Sechium.