Structure and distribution of heteromorphic stomata in Pterygota alata (Roxb.) R. Br. (Malvaceae, formerly Sterculiaceae)

Thirteen types of stomata along with 18 subtypes and 3 intermediate subtypes between brachyparahexacytic monopolar and dipolar are reported here to be present in the leaves of Pterygota alata (Roxb.) R. Br. var. alata and Pterygota alata (Roxb.) R. Br. var. irregularis (W. W. Sm.) Deb & S. K. Basu. The foliar epidermal cells are either polygonal, rectangular, or triangular, having either straight anticlinal walls or sinuous to undulate walls, and isodiametric in surface view. The observed stomata are amphibrachyparacytic, amphicyclocytic, anisocytic, anomocytic, anomotetracytic, brachyparacytic, brachyparahexacytic, brachyparatetracytic, cyclocytic, paracytic, parahexacytic (dipolar), paratetracytic and stephanocytic. Besides these, the presence of giant stomata is a significant finding. Cuticular striations are present on the subsidiary cells, epidermal cells and sometimes even on guard cells.