Abstract:Recent molecular systematic studies have consistently given results markedly different from the traditional classifications of Ephedra based on such macromorphological characters as the bract nature of ripe female cones, suggesting a serious conflict occurs between molecular and morphological characters. The cuticular micromorphology of the seed outer envelope (SOE) of living Ephedra encompassing 53 extant taxa of Ephedra were investigated. The results indicates that sculpture of SOE of Ephedra bears useful characters and includes 3 major types, viz. the Transverse lamellar type (T-type), the Papillate type (P-type), and the Smooth-Striated-Reticulate type (S-type). Further analyses implied that sculptural characters of SOE show correlation neither with macromorphology nor with molecular within Ephedra, indicating additional conflicting characters between macromorphology, micromorphology, and molecular. Several megafossil species associated with the Gnetales from Early Cretaceous in both Europe and E Asia were found to bear the T-type sculpture of SOE, indicating that species of Ephedra with the T-type seed envelope were once highly diversified in Early Cretaceous.
