Syagrus inajai (‘pupunharana’) is a native palm of Brazil, with phytogeographic prevalence in the Amazon region. A morpho-anatomical analysis was undertaken in order to gain a better knowledge on the embryonic development and germinative process of the S. inajai. Plant material was collected from the Campus of the Universidade Federal do Amazonas – UFAM, Manaus, Amazonas, Brazil, and processed using standard morphological and anatomical techniques. The development process of the embryo takes ~220 days, and is divided into four stages: proembryo, globular embryo, lateral cordiform and torpedo. The embryo is small, linear, and derived from the terminal cell of the proembryo, arising from mitotic divisions in the apical cell. The embryonic axis is straight, located in the proximal region, aligned parallel to the length of the embryo. The single cotyledon is formed by the ground meristem, procambium and protoderm. The procambium supplies the embryonic axis and the haustorium.

Elaeis oleifera is an oleaginous palm tree native to America. The fruit contains unsaturated fatty acid extracted from the mesocarp. The species is mainly used in breeding programs of E. guineensis in development of interspecific hybrids with higher oil yield and resistance to lethal yellowing. E. oleifera is propagated by seed, which requires the adoption of methods for breaking dormancy and increasing the germination rate. However, there are no studies on the morphology and anatomy of the seed and its ergastic substances; knowing its structure makes it possible to improve planting methods and make them more effective. The aim of the present study was to describe the morpho-anatomy and histochemistry of the seed, characterizing it and contributing information that assists in understanding dormancy. In seeds collected in the experimental area of Embrapa Amazônia Ocidental (Amazonas), morpho-anatomical and histochemical analysis was conducted to detect metabolites (starch, protein, lipids, carbohydrates, and phenolic compounds). The seeds vary in shape, oblong and ovate. The embryo has an oblique embryonic axis, composed of root apical meristem and shoot apical meristem with three leaf primordia. Phenolic compounds were found throughout the seed coat; there are lipids, protein, and pectin in the embryo and endosperm.