TAXONOMIC IMPLICATIONS OF LEAF MICROMORPHOLOGY IN THE GENUS HERITIERA (STERCULIACEAE)
A microscopic analysis study was conducted on the leaf micromorphology of six Heritiera species using observation under light and scanning electron microscope. Heritiera is a genus under Sterculiaceae, however based on new evidences the families of the Malvales order were re-positioned into nine subfamilies. Thus, it is important to continuously document additional anatomical and micromorphological information especially with advancement in microscopy technologies. The objective of this study is to identify taxonomically significant leaf micromorphology characteristics that can be used to assist species identification and classification. Methods involved were leaf clearing and staining for observation under light microscope, whilst dehydration, critical point drying and gold coating for observation under scanning electron microscope. The results have been presented in a matrix based on four foliar epidermal characters which were epidermal anticlinal wall shape, presence of cuticular waxes, types of stomata and trichomes. Several diagnostic characters were found in this study. These diagnostic characters which can be useful in species identification are the shape of epidermal anticlinal walls in H. elata, cuticular stellate wax sheet in H. littoralis and cyclotetrasitic stomata in H. simplicifolia. Among the 18 types of trichomes observed, nine can be used in Heritiera species identification. In conclusion, leaf micromorphological characteristics in Heritiera have significant taxonomic value which can be useful in species identification.