348 GRASS FAMILY 



(2) Leaves loose and almost thread-like; spike- 

 lets 4 mm. long C. neglecta 

 b. Leaves flat 



(1) Leaf-sheaths smooth; lemma equalled by 



the hairs C. hyperborea 



(2) Leaf-sheaths rough; lemma longer than 



the hairs C. scopidorum 



Calamovilfa Hackel 1890 Reed Grass 

 (Gr. kalamos, reed; Vilfa) 

 Spikelets 1-flowered, in a panicle, the axis not extending beyond the 

 flower ; glumes strongly unequal ; lemma with a ring of hairs at the base, 

 palet 2-keeled ; perennial. 

 Stems 2-6 ft. high; spikelet 6-8 mm. long; lemma 



twice as long as the hairs C. longifolia 



Catabrosa Beauvois 1812 Whorl Grass 



(Gr. katabrosus, eaten, from the fringed glumes) 



PI. 45, fig. 24. 



Spikelets usually 2-flowered, in a panicle with whorled branches ; 

 glumes much shorter than the lemma, unequal, obtuse ; lemma fringed or 

 toothed, slightly longer than the palet ; aquatic or swamp perennial. 

 Stems .5-2 ft. high; spikelets 2-3 mm. long; flowering 



scales 3-nerved C. aqudtica 



Cenchrus Linne 1753 Sandbur 

 (Ancient Greek name of the millet) 



Spikelets enclosed in spiny involucres, the latter in spikes ; glumes 2 

 with a sterile lemma, the lemma and palet enclosing a perfect flower ; an- 

 nual. 



Stems .5-2.5 ft. high; spikes 1-3 in. long; involucres 

 globose, spiny, 2-flowered C. tribuloides 



Chaetochloa Scribner 1897 Foxtail 

 (Gr. chaite, awn, chloe, grass) 

 (Setaria Beauv.) 

 Spikelets 1 -flowered or rarely with a second staminate flower, in dense 

 spike-like panicles, with bristles at the base ; glumes 2 with a sterile lemma ; 

 true lemma and palet enclosing a perfect flower ; annual or perennial. 

 1. Bristles at the base of each spikelet 1-4 

 a. Annual ; spikes dense, not interrupted, 3-10 cm. 



long C. viridis 



