PRIMARY STEM VASCULAR PATTERNS IN THREE SUBFAMILIES OF THE CRASSULACEAE

Abstract

Primary stem vasculature was investigated in seven genera and 69 species of the Cotyledonoideae, Kalanchoideae and Sedoideae. Vascular patterns in whole cleared stems were determined by number of leaf traces per leaf, number of leaf‐trace sympodia per stem, and connections between traces and sympodia. Four patterns were found in the Cotyledonoideae, eight in the Kalanchoideae and four in the Sedoideae. Similarities and differences among the patterns are discussed and possible phylogenetic trends are suggested. Changes in vasculature during ontogeny were observed in the Kalanchoideae and related to patterns found in mature stems. Many species in all three subfamilies reveal a relationship between phyllotaxy, number of sympodia per stem, and the intervals at which leaf traces are connected to each sympodium. Patterns of vasculature were found to support many of the intergeneric relationships suggested by other studies of this family.