Comparative Foliar Morphology and Anatomy of Lagerstroemia L. (Lythraceae) and its Taxonomic Implications

Abstract

The two introduced species of Lagerstroemia in Nigeria are differentiated with some anatomical characters of the leaf and stem using light microscopy. Generic constant features are hypostomatic leaf, anomocytic stomatal type, bicollateral vascular bundle, presence of striations and a ring of sclerenchymatous hypoderm which subtends the vascular bundles. Copious distribution of striations on both surfaces of the leaf epidermis, closed vascular bundles, presence of mucilagenous cells and 25% stomatal index distinguish L. indica from L. speciosa which has scanty striations that are restricted to the adaxial surface of the leaf epidermis, closed or open vascular bundles, absence of mucilagenous cells and 20% stomatal index. Perhaps, these characters may be confined to individuals from tropical Africa. A bracketed identification key is also presented.