Eco-Physiology in Selected Plant Species of Compositae: Comparative Study in Relation to Sun and Shade

The plants of Synedrella nodiflora Gaertn., Blumea membranacea DC., Spilanthes acmella L. have been investigated with reference to stomatal density and stomatal index, stomatal movement, tissue water relations, transpiration and growth behavior. In all the species, stomatal density was always lower in upper portion and varies in different part of the same leaf. Stomatal index was always lower in lower portion of the leaves. The water relation study of a plant explained the understanding of adaptability and survival strategies of species which suggests that S. nodiflora is drought resistant. Growth behavior of S. nodiflora under sun and shade treatment showed significant difference. Plant height, dry matter production, number of lateral roots were higher the plants of sun treatment than shade treatment. Influx of potassium ions caused a change in the opening of stomata. Maximum water loss of S. nodiflora occurred between 11.00 A.M to 3 P.M and less water loss in the morning and evening hours from both surfaces in both habitats. Maximum opening of stomata was found after 11 A.M and decreased at 5 P.M.