THE SHOOT APEX OF HYMENAEA COURBARIL (LEGUMINOSAE)

Shoot apices of Hymenaea courbaril are representative of those of many distichous plants, showing sharp intraplastochronic changes as a result of differential growth of the most recently formed primordium and the apical meristem proper. However, an unusual feature of this species is the complex arrangement of stipules. These enclose their own leaves as well as younger structures. Furthermore, the midregions of the stipules fuse ontogenetically at their bases, separating the newly formed leaf from the young shoot. Examination of apices of H. courbaril and H. stilbocarpa with the SEM shows similar morphological features in these two species.