The study of seedling morphology, before metaphyll sprouting, is a powerful tool in systematic studies in order to help identify monophyletic genera of Leguminosae. The study of seedling morphology leads to the discovery of temporary, basal and derived structures that are helpful to establish phylogenetic relationships, but may not be present in the adult individual. Cotyledon type, foliaceous or reserve, is one of the most important species characteristics. It facilitates the understanding of important strategic evolutionary changes as well as the ecological and evolutionary history of species of plants in relation to their habitat. The type of germination constitutes one of the most important characteristics used to identify species. In addition, characteristics such as shape of the limbus, edge, apex, eophyll position, presence or absence of latex or resin, length/width relationship of cotyledons, size and number of pinnae, as well as petiole winged or not, allow the identification of families, genera or even species. In Leguminosae, the study of plant morphology is used to confirm plant identification in the field, as well as to delimit generic and infrageneric identification in this family. Overall, Caesalpinioideae and Mimosoideae seedlings are considered epigeal, with foliaceous-type cotyledons; on the other hand in the Papilionoideae there is a predominance of hypogeal species with reserve cotyledons. The latter has also great variety, especially in tribes with ligneous species.
sistematics; blastogeny; habitat; cotyledon morphology
