Cenchrus setaceus (Pennisetum setaceum)

Cenchrus advena (Pennisetum advena)

Cenchrus alopecuroides (Pennisetum alopecuroides)

Cenchrus orientalis (Pennisetum orientale)

Cenchrus longisetus (Pennisetum villosum)

no secondary branching, leaf width 1-3(-4) mm with secondary branching, leaf width (2-)6-11 mm leaf width (1-)2-11(-14) mm leaf width 3-12(-15) mm leaf width 2-6 mm
peduncle with few short hairs peduncle rough to the touch peduncle pubescent peduncle glabrous peduncle pubescent
longest bristle 20-35 mm, 1-3 spikelets per fascicle longest bristle 13-34 mm, 1-4 spikelets per fascicle longest bristle 8-35 mm, 1-2 spikelets per fascicle longest bristle 14-31 mm, 1-4 spikelets per fascicle longest bristle 20-50 mm, 1 spikelet per fascicle

Photos: P. villosum 1 & 2: G. Fried