THE TAXONOMIC SIGNIFICANCE OF LEAF MICROMORPHOLOGY IN THE GENUS EUGENIA L (MYRTACEAE)

Leaf micromorphological features of both the Old and New World represe ntatives of Eugenia L. have been studied by light microscopy and scann ing electron microscopy. The leaves are hypostomatic and, in the major ity of species, the stomata are raised above the epidermis. Trichomes are usually present on the abaxial surface of the New World species. T he patterns of abaxial surface sculpturing and arrangement of outer st omatal rims are unique in the New World species. The majority of the O ld World species showed different anticlinal wall patterns on the adax ial and abaxial epidermises. In the majority of the New World species the anticlinal wall patterns are more or less the same except in E. ax illaris. The paracytic type of stomata, with a non-prominent T-piece c utinization at the poles of the guard cells, is a characteristic featu re of the New World species. The taxonomic significance of these featu res in identification and elucidation of species from both areas is di scussed. (C) 1996 The Linnean Society of London.