Epidermal Structure and Stomatal Development in Some Malvaceae and Bombacaceae

Abstract
Epidermal structure and development of stomata in 15 species of the Malvaceae and two of Bombacaceae are described. The cells of the epidermis are polygonal, isodiametric, or elongated with thick, straight, arched, or sinuous anticlinal walls and contain chloroplasts and abundant druses of calcium oxalate. Cuticular striations radiating from the guard cells or hair bases are noticed. Six types of glandular and non-glandular trichomes are seen. The mature stomata are anomocytic, anisocytic, and paracytic in the members investigated of both the families. The ontogeny of anisocytic and paracytic stomata is syndetochelic or mesogenous, while that of anomocytic is haplocheilic or perigenous. An abnormal stoma with a single guard cell is also observed. An increase in number of subsidiary cells in anisocytic stomata is due to the division of the subsidiary cells.