Epidermal Patterns of the Leaf Blade in Selected Andropogoneae

Epidermal patterns of the widest portion of the leaf blade of selected members of the Andropogoneae were studied. These included 23 genera and 71 species, some of which were duplicates, making a total of 83 entries. The specimens were collected by Dr. H. C. Reynolds in the Andropogoneae Nursery, a common transplant garden having similar environmental conditions and located at Oklahoma State University at Stillwater, Oklahoma. Spidermal patterns were studied mainly by the peel method, using acetone and cellulose acetate film. These were compared with peridermal sections and some whole cleared mounts which were made by Dr. Reynolds. The leaf epidermal elements, silica cells, bicellular-microhairs, cushion hairs, macro-hairs, swollen hairs, bulbous hairs, papillae, stomata, and long cells were observed on the abaxial and adaxial surfaces, from the leaf margin to mid vein. Also, the arrangement of epidermal elements, silica cells, stomata, and trichomes was examined. These were observed on the abaxial surface (lower surface) more in detail than on the adaxial surface (upper surface). Bicellular-microhairs and silica cells were found to be the most diagnostic characters, and the arrangement of silica cells, trichomes and stomata were also found to be important for classification of species of the Andropogoneae. In the members of the Andropogoneae investigated, it was found that the cushion hairs, swollen hairs, spicules, papillae and stomatal distribution were more variable characters. Epidermal patterns are more important for identification or grasses by vegetative characters than the individual elements