The vascular organization in the nodes of 15 genera from familyCaesalpiniaceae was investigated. The leaves were alternate, stipulate and 2-foliate in Cynometra, Hardwickia, Bauhinia while pinnately compound in other taxa. The foliar nodes were trilacunar, three-trace in majority of the plants. It was pentalacunar, five-traced in Caesalpinia and Moullava. An intermediate structure i.e. tetralacunar, (or four-traced) node was also noted in Moullava. Multilacunar multi-trace node as well as pentalacunar five-trace node was observed in Caesalpinia bonduc and Senna alata. In certain taxa, a median bundle gave rise to medullary bundles, which were extended inside the stelar structure of the rachis. The results are discussed with respect to the evolutionary conception of node.
Caesalpiniaceae, Node, Nodal evolution
