Light and scanning electron microscopic study of genus Echinochloa species inhabited in Pakistan.

Grass taxonomy is quite problematic and insignificant taxonomic work has been done on Echinochloa with special reference to Pakistan. Therefore, the present study was carried out to provide taxonomic keys for the identification of this genus through microscopic epidermal leaf anatomical parameters. Light microscopy and scanning electron microscopy were done to delimit the different species. Special structures like hook cells, short and long cells, stomata, macro- and micro-hairs, prickles and silica bodies showed a lot of variation among each species. For instance, E. frumentacea can be distinguished from E. walteri by the presence of macro hairs between the veins. Furthermore, E. crus-galli can be distinguished from E. frumentacea in terms of macro hair size, that is, 45-60 μm and 20-60 μm, respectively. Similarly, E. colona showed marked variations in terms of prickles abundance from E. frumentacea. Overall results of this research reports valuable qualitative and quantitative diagnostic futures for the genus Echinochloa.