Plants perennial, or annual in temperate climates; cespitose. Culms 1-1.5 m, erect, sometimes branching above, pubescent beneath the panicle; nodes glabrous. Leaves burgundy (rarely green); sheaths glabrous, margins ciliate; ligules 0.5-0.8 mm; blades 33-52 cm long, 6-11 mm wide, flat, antrorsely scabridulous, margins ciliate basally, midvein not noticeably thickened. Panicles 23-32 cm long, 30-58 mm wide, fully exerted from the sheaths, flexible, drooping, burgundy (rarely pale or whitish-green); rachises terete, pubescent. Fascicles 10-17 per cm, disarticulating at maturity; fascicle axes 1-2 mm, with 1-3 spikelets; outer bristles 43-68, 1.2-18.5 mm, terete, scabrous; inner bristles 4-10, 11.7-25 mm, long-ciliate; primary bristles 21.3-33.6 mm, ciliate, noticeably longer than the other bristles. Spikelets 5.3-6.5 mm; pedicels 0.1-0.3 mm; lower glumes 0.5-1 mm, veinless; upper glumes 1.9-3.6 mm, 0-1-veined; lower florets staminate; lower lemmas 4.7-6.1 mm, 5(6)-veined; lower paleas 4.5-5 mm; anthers 2-2.5 mm; upper florets not disarticulating at maturity; upper lemmas 5.2-6.1 mm, 5-veined; anthers 2.5-2.7 mm. Caryopses concealed by the lemma and palea at maturity. 2n = 54.

The origin of Pennisetum advena is uncertain. It is frequently cultivated as an ornamental, usually being sold as Pennisetum setaceum 'Rubrum'.