Anatomía y ontogenia de semillas de helicteres lhotzkyana (Sterculiaceae)

Abstract

Fueron estudiadas la anatomía y la ontogenia de las semillas de H. Lhotzkyana, con el fin de conocer la estructura y el origen de su aleta. Fueron analizadas semillas maduras de H. baruensis, representante del género, con el fin de comparar los dos tipos de semillas. La exotesta está constituída por esclereidas alargadas longitudinalmente, la endotesta está formada por células parenquimáticas con pequeños grupos de células taníferas. El principal mechanical layer de la semilla es el exotegmen, formado por macroesclereidas radialmente alargadas, el meso y endotegmen son taniníferos. El presente estudio muestra que la aleta de las semillas de H. Lhotzkyana se desarrolla a partir del rafe, and consists of parenchymatic cells sourronding the rapheal vascular bundle and both sclerenchymatic epidermis.

The anatomy and ontogeny of the seeds of H. Lhotzkyana was studied, in order to know the structure and origin of its wing. Ripe seeds of H. baruensis, representative of the genus, were also analized so as to compare both kind of seeds. The exotesta is made of longitudinally elongated sclereids, endotesta is parenchymatic with small patches of tannin cells. The principal mechanicallayer of the seed coat is the exotegmen, formed by radially elongated macrosclereids; meso- and endotegmen are tanniniferous. The present study shows that the wing of the seeds of H. Lhotzkyana develops from the raphe, and consists of parenchymatic cells sourronding the rapheal vascular bundle and both sclerenchymatic epidermis.