XVI International Botanical Congess

Smilax genus has a wide distribution and, mostly, Pantropical. Presents, besides aerial climbing stem, which can reach several meters, with vegetative and floral buds, an another bud system, that grows underground. In Smilax quinquenervia, embryo plumule gives rise so an aerial branch that show, in the beginning, an axe with 3-4 nodes in which buds are protected only by cataphylls. The eophyl only arise above this region. Serial sections were made and observed in light microscopy. An underground system analysis permitted to observe that is, actually, a stem, with secondary growth, throughout a lateral meristem. This organ origin is from the cotyledonary bud and all adventitious roots that the plant presents, arise from this organ, which it was decided to name by rhizophore, as because its origin as by its anatomic features. The presence of several stomata on this organ epidermis, possibly, mean that this structure presents aerial clorophyled ancestor.