Astronium graveolens is a treelike member of the family Anacardiaceae, spreading from Mexico to the south center of South America. The fruit is a pseudosamara with a uniseriate exocarp adherent to the endocarp. The mesocarp is parenchymatic and presents large secretory ducts associated with vascular bundle and arranged side by side, near to the endocarp. The parenchymatic endocarp is biserial, and the layer enveloping the locule is slightly radially elongated. The ovule anatropous, unitegmic, and crassinucellate and has an evident dorsal raphe and a tanniniferous hypostase. It presents an apical-lateral insertion in the ovary and shows a placentary obturator. The testa which strongly adheres to the pericarp shows the cells of the inner epidermis with dense cytoplasm, indicative of an endotestal condition. The mature seed coat is formed from the remaining of the testa, funicle, raphe-chalaza region and hypostase, presenting two distinct regions: one is dark brown patch pachychalazal and other pale brown tegumentary. The embryo is axial investing.
Anacardiaceae; Astronium graveolens; pericarp; seed; anatomy
