Abstract

The foliar micromorphology of Arctotis arctotoides (L.f.) O. Hoffm. a medicinal plant in the Eastern Cape Province, South Africa was investigated using the Scanning Electron Microscope (SEM). The leaf surfaces of the plant were characterized by anisocytic stomata, glandular and non-glandular trichomes. The abaxial surfaces had more stomata and glandular trichomes than the adaxial surfaces of the leaf. Crystal deposits were also observed around the stomata and near the glandular trichomes. Energy dispersive X-ray spectroscopy showed that Na, Mg and Ca were the major constituents of the crystals. Naturally, distinct morphological variations existed among the ultra structures on the leaf surfaces of the plant. The distributions of the stomata and the two types of trichomes on both surfaces also differed both in shape and in structure. The presence of glandular trichomes on the leaf surfaces of this herb may serve as secretory sites where secondary metabolites are produced.

Key words: Arctotis arctotoides, foliar micromorphology, stomata, trichomes, crystals.