Comparative leaf and stem anatomy of ten Piper species from Indonesia

The genus Piperwithover 700 species distributed in tropical and subtropical areas of the world has a considerable number of species with economic importance as spices and herbal medicine. In this study the anatomical characters of leaf and stem on 10 species of Piperfrom Bogor Botanical Garden, Indonesia were observed in relationwith their function as oil-accumulating organs. The objective of this study wasto explorethe anatomical variabilityamong species. Observations on anatomical characters were done onleaf epidermal and cross section as well as stemcross section prepared using paraffin embedding method. Results indicated that there were structural variations on the epidermal features, mesophyll, secretory cells and secretory cannals of leaves, as well as variation on the ratio of medullary and peripheral vascular bundles on stem. Results of this studyprovideadditional taxonomic evidence to confirm differences between Piperspecies, and serve as supporting data for identification based on internal structures. Data on the comparativeanatomy of leaf and stem also contributes to the selection of the right materialsfor the extraction of essential oils from various Piperspecies based on the presence of secretory cells.