Micromorphological Investigation of Foliar Anatomy of Genera Aconogonon and Bistorta of Family Polygonaceae

ABSTRACT Leaf epidermal studies have been carried out on six species belonging to two genera of the family Polygonaceae. The use of light microscopy has made possible in depth to study leaf surface features such as shape of epidermal cells, stomatal pattern, their distribution on adaxial and abaxial leaf surface and trichomes types. Epidermal cell shapes are variable but generally polygonal. Six different stomatal patterns are reported for Aconogonon (Meisn.) Reichenb. and Bistorta Adans. Variation among glandular and non glandular trichomes was also noted. Cyclocytic stomata are recorded first time in Aconogonon alpinum (All.) Schur. This anatomical study has taxonomic importance, on the basis of which identification keys are prepared. Key Words: Polygonaceae; Staurocytic stomata; Cyclocytic; Peltate trichome; Spheroidal trichomes INTRODUCTION Polygonaceae is a cosmopolitan family containing approximately 1,200 species from 48 genera (Freeman & Reveal 2005; Sanchez & Kron, 2008). They are group of morphologically different herbs, shrubs, small trees or climbers characterized by simple leaves with covering ochrear stipules, unilocular ovary and endospermic seeds (Hutchinson & DaLziel, 1954; Brummitt, 1992). The family is generally considered to be comprised of 30 to 49 genera. They are distributed worldwide from the tropics to the arctic, but most of the species are concentrated in the northern temperate region (Heywood, 1978). Metcalfe and Chalk (1950) gave comprehensive report on foliar anatomy of the Polygonaceae. Lersten and Curtis (1992) examined foliar anatomy of genum