Echinochloa

(Ligules absent in our species)

1. Awn usually > 10 mm long…5

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

2. Lower floret usually staminate… (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… (sheaths glabrous)

3. Spikelets awned; spikelet hairs papillose-based or not; inflorescence branches with  secondary branchlets (at least in E. muricata)…4

4. Spikelet hairs with papillose bases… (sheaths glabrous)

4. Spikelet hairs not papillose…5

5. 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…(spikelet hairs may be papillose in extra-regional material)

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