Morfologia e anatomia de frutos e sementes de Styrax camporum Pohl. (Styracaceae), espécie de cerrado do Estado de São Paulo

Abstract

Styrax camporum Pohl. (Styracaceae), a typical tree of the Brazilian cerrado, is popularly known as benjoeiro, estoraque-do-campo, cuia-do-brejo, canela-poca, fruta-de-pomba, pindaiba and laranjeirinha. In Brazil, there are about 25 species of Styrax; three of them are found in the cerrado. Morphological and anatomical works on this species are scarce. Some include the vegetative and few the reproductive organs. These latter emphasizing ones, only the whorls; no paper was found on fruit and seed. Considering this literature gap, the aim of this work is to describe S. camporum fruits and seeds morphological and anatomical aspects, in different developmental stages, in order to characterize them and to observe structural patterns which indicate adaptation to the cerrado. Individuals from the cerrado region of Pratânia and Botucatu, Sao Paulo State, Brazil, were analized and processed by standard techniques. Developing fruits were classified into four stages: I — initial stage, characterized by floral bud ovaries; II — post-anthesis flower ovary and young fruits; III — non-mature adult fruits; IV — mature fruits. S. camporum fruit is fleshy and monospermic, with a persistent calyx. The pericarp presents a unisseriate exocarp, with stellate lignified trichomes and dome-shaped cells of irregular sizes. The mesocarp consists of multisseriate parenchyma, radially elongated up to maturity. Druses and phenolic idioblasts are disperse in the mesocarp. Vascular bundles are observed in the mesocarp inner third part. In spite of the fact that the fruit of this species is classified as drupe, its endocarp is composed of only a few fiber layers, without forming the pyrene with the typical hardness of these fruits. The endocarp fusion with the seed coat is not seen. The seed is typical of the Styracaceae; it is unitegmic, with multisseriate and thick testa. The exotesta is unisseriate and some layers of stone cells are seen in the outer meso