Detailed macro and micromorphology of grasses caryopsis using scanning electron and light microscopy

Abstract

Micromorphology of 15 grass caryopsis was investigated through scanning electron microscopy for its implications in the identification of grasses. Both macro and micromorphological characters especially caryopsis shape and surface morphology were found significant in the taxonomic diagnosis. Shape morphology of caryopsis varied among the species and lanceolate, fusiform, narrow ellipsoidal, ovate, elliptical, planoconvex, fusiform, linear ovate, broadly elliptical, broadly pllipsoidal, plano-convex, oblique ovate, and subglobose shapes were recorded. Digitaria nodosa (3.31 Â 0.7 mm) and Echinochloa crus-galli (3.26 Â 1.44 mm) had the largest caryopsis size, while Acrachne racemosa (0.76 Â 0.54 mm) and Eragrostis minor (0.62 Â 0.38 mm) had the smallest caryopsis size. Macro and micromorphological characters were useful for the diagnosis of genus and species. Utilizing both qualitative and quantitative character taxonomic key at generic and species level were made.