Leaf anatomy and foliar trichomes in Heliotropiaceae and their systematic relevance

Leaf anatomy and the distribution of foliar trichome types of 65 species of Heliotropiaceae have been investigated. The aim was to evaluate the systematic relevance of their diversity as compared to recent findings of systematic relationships within the family. The results of leaf anatomy patterns, especially venation, vascular system, various foliar trichome types, and localization of crystals are of surprisingly high systematic value and prove the actual proposed subdivision of this family based on molecular results. Each main clade identified in the molecular studies is well characterized on the basis of leaf anatomy.