XVI International Botanical Congess

Histology of roots, shoots, leaves, tendrils, inflorescences and fruit was compared in Muscadinia species V. rotundifolia and cultivars of Euvitis species V. labrusca and V. vinifera. Unique to Muscadinia are: dense distribution of lenticels in the bark of internodes, clusters and tendrils, a persistent periderm arising in stem cortex, not in phloem, secondary phloem with boundary fibers lining rays and only weakly developed tangential bands of phloem fibers as found in Euvitis, more compact leaf mesophyll, fruit abscission at the ovary base in some cultivars, gum-filled cells in all organs and tissues, and a different phyllotactic arrangement in overwintering buds.