Banisteriopsis and Diplopterys together have ca. 100 species and occur throughout the Americas, especially in South America. The structure of the reproductive organs of Malpighiaceae is poorly known, so this work aims to analyze the morphology, anatomy and ontogeny of the seeds of B. campestris, B. oxyclada, B. stellaris and D. pubipetala. The ovules are suspended, subcampylotropous, bitegmic and crassinucellate. The inner integument is shorter than outer, and only the latter constitutes the micropyle. The nucellus is very large and projects through micropyle, coming in contact with the funicular obturator which is less conspicuous in D. pubipetala. Banisteriopsis and Diplopterys have small, dark yellow pachychalazal seeds; at maturity, the seed coat collapses, and only the exotesta with phenolic compounds and vascular residues can be distinguished; the seeds are exalbuminous and the embryo fills the seminal chamber; it has a short, straight embryo axis, with well-developed fleshy cotyledons. The embryo reserve is composed basically of lipids, with small, scattered starch grains; many druses are also observed. Structure and development of these seeds are very similar to one another and to other Malpighiaceae already described. This is the first report of obturator and pachychalaza in Malpighiaceae.
seed; Banisteriopsis; Diplopterys; anatomy; morphology
