The taxonomic significance of leaf micromorphology in the genus Eugenia L. (Myrtaceae)

Abstract

Leaf micromorphological features of both the Old and New World representatives of Eugenia L., have been studied by light microscopy and scanning electron microscopy. The leaves are hypostomatic and, in the majority of species, the stomata are raised above the epidermis. Trichomes are usually present on the abaxial surface of the New World species. The patterns of abaxial surface sculpturing and arrangement of outer stomatal rims are unique in the New World species. The majority of the Old World species different anticlinical wall patterns on the adaxial and abaxial epidermises. In the majority of the New World species the anticlinical wall patterns are more or less the same except in E. axillaries. The parapcrytic type of stomata, with a non-prominent T-piece cutinization at the poles of the guard cells, is a characteristic feature of the New World species. The taxonomic significance of these features in identification and elucidification of species from both areas is discussed.