Phenotypic Diversity of Eragrostis Wolf in Egypt

Abstract

Eragrostis Wolf is considered one of the largest genera of family Gramineae (Poaceae). It is a cosmopolitan genus and represented in Egypt by 14 taxa. The species limits are often overlapping due to the wide range in variation within this genus. So, it is difficult to establish specific boundaries and diagnostic characters. The main goal of this work is to establish the limits and the diagnostic characters in the Egyptian taxa, using cluster analysis and principal coordinates analysis based on morphological characters. Interactive keys have been designed as an aid for online identification and looking for diagnostic characters. The morphological characters of Inflorescence, spikelets, panicle, glumes, palea keels and caryopsis are very important and necessary in the identification of the studied species. The results of coordinate analysis as well as UPGMA dendogram revealed that Egyptian Eragrostis species can be divided into 3 groups: group (A) includes: E. minor and E. cilianensis; group (B) includes E. tef, E. tenuifolia, E. sarmentosa, E. barrelieri, E. aegyptiaca and E. pilosa while group (C) includes E. aspera, E. ciliaris, E. japonica, E. lepida, E. tenella, and E. tremula. More research is needed to confirm the occurrence of several taxa in Egypt, such as Eragrostis purpurascens and E. nitida, which have been reported in some publications but are uncertain.