WOOD AND BARK ANATOMY OF CARICACEAE - CORRELATIONS WITH SYSTEMATICS AND HABIT

Wood and bark anatomy are described for four species of three genera o f Caricaceae; both root and stem material were available for Jacaratia hassleriana. Wood of all species lacks libriform fibers in secondary xylem, and has axial parenchyma instead. Cylicomorpha parviflora has p aratracheal parenchyma cells with thin lignified walls; otherwise, all cell walls of secondary xylem in Caricaceae except those of vessels h ave only primary walls. Vessels have alternate laterally elongate (pse udoscalariform) pits on vessel-vessel interfaces, but wide, minimally bordered scalariform pits on vessel-parenchyma contacts. Laticifers oc cur commonly in tangential plates in fascicular secondary xylem, and r arely in xylem rays. Proliferation of axial parenchyma by zones of tan gential divisions is newly reported for the family. Bark is diverse in the species, although some features (e.g., druses) are common to all. Wood of Caricaceae is compared to that of two species of Moringaceae, recently designated the sister family of Caricaceae. Although the woo d and bark of Moringa oleifera, a treelike species, differ from those of Caricaceae, wood and bark of the stem succulent M. hildebrandtii, t he habit of which resembles those in Caricaceae, simulate wood and bar k of Caricaceae closely. Counterparts to laticifers in Moringaceae are uncertain, however. Phloem fibers of Caricaceae form an expansible pe ripheral cylinder of mechanical tissue that correlates with the stem s ucculence of most species of Caricaceae.