Leaf epidermal features and stomatal ontogeny in Talinum triangulare (Jacq.) Willd

Abstract

The structure and ontogeny of stomata in Talinum triangulare were examined to determine the developmental pathway of stomata in the leaves. Young leaves at different stages of growth and mature leaves were peeled, bleached in 70% ethanol, stained with alcian blue and examined under the microscope. Clear photo-micrographs were taken with trinocular research microscope (Amscope T340B) fitted with Amcope digital camera. The transitional stage of the stomata was mainly anisocytic in nature but the mature stomata were only paracytic. The ontogeny of the stomata was mesogenous and the plant was amphistomatic and glabrous. The ratio of the stomata index on the adaxial (19.02±1.82) to abaxial (36.08±3.52) layer was 1:2. The anticlinal walls of the mature leaves were wavy on both adaxial and abaxial surfaces and straight in the young leaves. The epidermal cell shapes were irregular on both surfaces but polygonal in the young leaves. The length and width of the stomatal complex, guard cell and the epidermal cells were higher in the adaxial surface than the abaxial surface. The stomatal ontogeny of this species could serve as an important taxonomic tool in delimiting the species.