Morphology of Bapeba (Pouteria grandiflora (A.DC) Baehni, Sapotaceae)

Abstract

The genus Pouteria Aublet. is the largest in the family Sapotaceae, with approximately 188 species in neotropics, being required additional research for a better understanding of its taxonomy. Pouteria grandiflora is a tree widespread along the sandy plains of the Brazilian coast, actually in the IUCN Red List. This study describes the flower and leaf morphology and compared the anatomy of P. grandiflora in two distinct light expositions: shaded and exposed leaves. The amplitude of variation for these traits was valuated within a small geographical area in the Restinga of Rio das Ostras (RJ). Leaves fully expanded from three mature individuals were collected and fixed in FAA 70. The flower morphological features are similar to those by other authors, but it is important to point out that species show some differences as in their petals (4-6), stamens (5-6) and staminodes (4-6). The internal morphology analyses revealed features as: unilayered epidermis; dorsiventral symmetry; palisade parenchyma 1-3-layered; midvein with the vascular tissues collateral, arranged in an arc surrounded by lignified sheath; idioblasts with calcium oxalate crystals were found along the entire leaf blade, petiole and associated with vascular system; and hypostornatic blade with anomocytic or paracytic stomata. The most significant differences between leaves were: thinner lamina in shaded leaves, coriaceous in sun-exposed plants and leaves that develop under high light incidence presented well-developed palisade cells and had greater mesophyll width when compared with shaded leaves. The leaf structure of specie has shown xeromorphic characters that can be related environmental conditions. These results highlight the role of anatomy as an important tool to be exploited in taxonomic studies of other species within the Sapotaceae.