Cenchrus Linnaeus. Subfamily: Panicoideae. Tribe: Paniceae. Subtribe: Cenchrinae. supertribe: Panicodae. clade: "PACMAD". Burgrass, Sandspur.
A genus of about 90-150 species, primarily tropical and subtropical. The circumscription of Cenchrus is here treated broadly, including Pennisetum (Chemisquy et al. 2010). Others have disagreed, including Wipff & Shaw (2018a), who prefer to treat our species in Cenchrus s.s., Pennisetum, and Cenchropsis.
ID notes: Spikelets of Cenchrus are subtended by an involucre of spines and/or bristles which are (in many of our species) fused into a bur. Bristles are narrow-based and terete. Spines are broad-based, and somewhat flattened (not terete) in cross-section, at least basally.
Ref: Chemisquy et al. (2010); Crins (1991); Donadío et al. (2009); Herrera Arrieta & Peterson (2018); Stieber & Wipff (2003) In Flora of North America Editorial Committee (2003a); Verloove (2012); Ward (2010b); Wipff (2003k) In Flora of North America Editorial Committee (2003a); Wipff & Shaw (2018a). Show full citations.