A Revision of Sechiopsis (Cucurbitaceae)

Abstract

Sechiopsis is a group of unusual cucurbits distinguished by pouched nectaries and winged fruits. The genus consists of five species; two newly described (S. diptera and S. distincta) and one transferred from the monotypic Pterosicyos (S. laciniatus). Sechiopsis Naud. is a small genus of Mexican and Guatemalan cucurbits with distinctive winged fruits and pouched nectaries. Like other members of the tribe Sicyoeae, the species of Sechiopsis have small greenish flowers and sin- gle-seeded indehiscent fruits. Unlike their close relatives, the chayote and tacaco (Sechium L. s.l.), there is no known economic use for the species of Sechiopsis. Because of their unusual fruits, however, they do have some potential as hor- ticultural curiosities. Recent collections from the mountains of Chiapas and subsequent review of herbarium material have shown that a revision of Sechiopsis is necessary. Two new taxa are here described and the monotypic Pterosicyos T. Brandegee placed in synonymy. The defining characters of Sechiopsis are nectaries consisting of groups of multicellular glandular trichomes within out- pocketings of the hypanthium, and winged dry fruits with wings that have entire margins and are of equal size. The genus, as here circum-