Epidermal Structure and Stomatal Ontogeny in Some Polygonales and Centrospermae

Abstract

The epidermal structure and ontogeny of stomata in 19 species of Centrospermae and two of Polygonales are described. The cells of the epidermis are polygonal, isodiametric, or elongated in various directions and arranged irregularly. The anticlinal epidermal walls are thick, sinuous, straight, or arched. Eleven types of glandular and eglandular trichomes have been observed. Six types of stomata: anomocytic, paracytic, stomata with a single subsidiary cell, diacytic, anisocytic, and transitional between diacytic and paracytic, have been noticed in the species investigated. The ontogeny of anomocytic stomata is haplocheilic or perigenous, while that of the other five types is syndetocheilic or mesogenous. Abnormal stomata with a single guard cell, unequal guard cells, aborted guard cells, and arrested development are common. Groups of stomata are also frequent but contiguous stomata are rather rare.