(Ligules absent in our species)

1. Awn usually > 10 mm long; spikelet hairs not papillose…4

1. Awn usually < 10 mm long, or absent…2

2. Lower floret usually staminate…E. paludigena (large grasses often > 1 m tall, having short awns)

2. Lower floret sterile…3

3. Spikelets with no awn (or second glume or sterile lemma with pointed caudate apex to 2 mm long). Spikelet hairs not papillose-based; inflorescence branches not secondarily branched…E. colona (sheaths glabrous)

3. Spikelets awned; spikelet hairs papillose-based or not; inflorescence branches with secondary branchlets (at least in E. muricata)…E. muricata (sheaths glabrous)

4. Sheaths usually glabrous or with soft hairs; awns 0-50 mm mm. Fertile lemma with ring or tuft of trichomes near the tip, which tends to wither…E. crus-galli (spikelet hairs may be papillose in extra-regional material)

4. Sheaths usually hispid; awn usually 10-25 mm. Fertile lemma with no ring of trichomes near the tip, which is membranous but not withered..E. walteri