The Organization of the primary Vascular System in the Rhoeadales

In their nodal anatomy the Rhoeadales are not sharply distinguishablefrom the Ranunculaceae, but there is a difference in emphasis,the tendency in Rhoeadales being to draw together into a narrowsector of the stem the whole of the vascular supply to leafand branch. In many cases there is marked enlargement of themedian leaf-gap, and features occur which are otherwise rareor unknown among dicotyledons. The effect of vascular studiesis to confirm the existence of close affinities between thefamilies of the Rhoeadales, to bring the Ranunculaceae intothe same field of comparison, and to stress the separation ofthe Ranunculaceae from many of the other amilies of the Ranales.