Diverse Nodal Types in Rhododendron

ARNOLD ARBORETUM [voL.49 normally continues across the cortex and into the petiole as a single unit and remains unbranched as far as the base of the lamina.Rarely, lateral branches may occur as the petiole approaches the lamina.Such branches have been observed in Rhododendron camelliaeflorum, R. tsangpoense, R. maddenii, and R. scabrifolium.This simple type of node, or slight modifications of it presently to be described, occurs in all the 136 species examined from the groups listed in Taste 1.These groups comprise approximately 55 percent of the species in the whole genus.Rhododendron albiflorum.Leaf base, showing origin of two accessory hander outside the abscission layer.