Cenchrus americanus (L.) Morrone

synonyms: Pennisetum glaucum, Pennisetum typhoides


pearl millet


Info

Subfamily: Panicoideae
Genus etymology: Cenchrus = "millet" [Greek]. However this is a misnomer, the only millet species in this genus is C. americanus, and this was treated as Pennisetum when Cenchrus was erected.
Species etymology:
Photosynthetic type: C4 (warm season)
Nativity: questionable - intentional
First recorded in Hawaiʻi: 2004

Map

 Distribution of Cenchrus americanus in Hawaiʻi.

Inflorescence

Cenchrus americanus Inflorescenceimage credit: 伍志龍

Plant

Cenchrus americanus Plantimage credit: u_hassan
Cenchrus americanus Plantimage credit: u_hassan
Cenchrus americanus Plantimage credit: 伍志龍

Description

Plants annual. Culms 50-300 cm, erect, branching; nodes glabrous. Sheaths glabrous or pubescent, with or without ciliate margins; ligules 2-5 mm; blades 15-100 cm long, 7-70 mm wide, flat, glabrous or pubescent. Panicles terminal, 4-200 cm long, 2-70 mm wide, fully exerted from the sheaths, erect; rachises terete, densely pubescent. Fascicles 33-160 per cm; fascicle axes 1-28 mm, persistent, with 1-9 spikelets; outer bristles 44-131, 0.5-6 mm; inner bristles 6-19, 4-6 mm, plumose; primary bristles 5.5-6.3, ciliate, some¬times noticeably longer than the other bristles. Spikelets 3-7 mm; pedicels 0.6-1.8 mm; lower glumes absent or to 1.5 mm, veinless; upper glumes 0.5-3.5 mm, 3-5-veined; lower florets staminate or sterile; lower lemmas 1.5-6 mm, glabrous, 3-7-veined, margins ciliate; lower paleas vestigial or fully developed, margins ciliate; anthers 2.2-2.5 mm, penicillate; upper florets coriaceous, shiny; upper lemmas 4.3-7 mm, 5-7(9)-veined, margins ciliate; upper paleas 3.4-3.9 mm, pubescent, at least near the base, margins ciliate; anthers 2-2.2 mm, penicillate. Caryopses 2-5.5 mm long, 1.6-3.2 mm wide, protruding from the lemma and palea at maturity. 2n = 14.
(Description source: Barkworth, M.E., Capels, K.M., Long, S. & Piep, M.B. (eds.) 2003. Flora of North America, north of Mexico. Volume 25. Magnoliophyta: Commelinidae (in part): Poaceae, Part 2. Oxford University Press, New York. 783 pp http://floranorthamerica.org/Cenchrus_americanus )