Morfoanatomia e histoquímica da semente de sororoca (Phenakospermum guyannense (Rich.) Endl. - Strelitziaceae)

Phenakospermum guyannense, popularly known in the Amazon as sororoca, is usually found along rivers and in ombrophilous environments. The objective of this study was to describe the morpho-anatomy and histochemistry of mature seeds of P. guyannense collected at the Urubuí Waterfall, Presidente Figueiredo, Amazonas state, Brazil. Seed anatomy was studied using a light and a scanning electron microscopes (SEM). Histochemical tests were performed to identify phenolic compounds, starch, protein and lipids. The mature seed of P. guyannense is stenospermic, with a black seed coat composed of several layers of different cell types, with most containing phenolic compounds. The hilum is punctiform, surrounded by cells, which form the aryl. The endosperm is solid, formed by tetrahedral cells containing starch and protein. The embryo, which is cylindrical and located in the proximal region, is basal capitate, with cells containing lipids and proteins and is composed of a slightly dilated hypocotyl-radicle axis. The haustorium is flattened and located in the distal region