Ontogenetic analysis of the pericarp of species of Mimosa Linnaeus (Fabaceae, Mimosoideae)

The objectives were to analyze ontogenetically the fruits of Mimosa daleoides, M. dolens var. anisitsii and M. orthacantha, comparing themselves and identifying them correctly. Collections were made in Botucatu, São Paulo State, Brazil, and the fruits in several development stages were prepared according to usual anatomical techniques. During pericarp development, dendritics and spine-like emergences are produced, and an adaxial meristem is installed, originating the multiseriate lignified outer endocarp and the uniseriate parenchymatous inner endocarp. The structure of pericarp follows the pattern for Fabaceae, with uniseriate exocarp, parenchymatous and vascularized mesocarp, and heterogeneous endocarp. In M. daleoides and M. orthacantha, false septa are formed where transverse fragmentation of the pericarp occur; moreover, lignified tissue is produced externally to the ventral and dorsal bundles. Therefore, the fruits of these two species are craspedium and M. dolens var. anisitsii produces legumes with passive dehiscence.

anatomy; fruit; Mimosa ; morphology; ontogenesis