GRAMINEAE (GRASS i<"AMILY) 



145 



52. GYMNOPdGON Beauv 



Spikelets with 1 perfect flower, sometimes 1 or 2 neuter or staminate subses- 

 sile florets above the perfect one, remote along one side of a flliform continuous 

 rliaoliis, forming slender unilateral spikes; rhachilla prolonged beyond the floret 

 as a slender often awned rudiment ; glumes narrow, subequal, rigid, scabrous on 

 tlie strong keel, equaling or exceeding the florets ; lemma thin, bearing a slender 

 straight awn from just below the apex ; palea about as long 

 as the lemma. — Perennials, with short rather broad rigid 

 leaves and numerous slender spikes, at first erect, at length 

 widely divaricate or reflexed. (Name composed of yufi.v6s, 

 naked, and irdyoiii, a beard, alluding to the reduction of the 

 abortive flower to a bare awn.) 



1. G. ambiguus (Miohx.) BSP. Culms tufted from a short 

 rootstook, .rigid, erect or ascending, 2-5 dm. high; sheaths 

 overlapping, blades often approximate, thick, rigid, spreading, 

 i-6 cm. long, 1 cm. or more wide ; spikes solitary or in 2's 

 along a striate axis, becoming widely divaricate when exserted 

 from the sheath, spikelet-b earing to the base; awn of floret 

 longer than the glabrous lemma; rudiment long-awned. 

 {G. racemosus Beauv.) — Sterile sandy or gravelly ground, 

 N. J. to Mo., Fla., and Tex. Aug., Sept. Pig. 135. 



2. G. brevifblius Trin. Resembling the preceding ; culms 

 more slender, from a decumbent base ; leaves 2-4 dm. long, 4-9 mm. wide, 

 involute in drying ; spikes usually less numerous, more distant, naked at the 

 base, spikelet-bearing from about the middle; awn shorter than the hairy lemma ; 

 one or two sterile florets sometimes present, rudiment usually awnless. — Sandy 

 ground, N. J., and south w. 



135. G. ambigiuus. 

 Inflorescence x i/g. 

 Spikelet x 21/2. 



53. CHLdRIS Sw. 



Spikelets with 1 perfect floret, sessile in 2 rows along one side of a continuous 

 rhachis, forming unilateral spikes ; rhachilla prolonged behind the palea and bear- 

 ing 1 or more rudimentary awned sterile lemmas ; glumes unequal, narrow, 

 acute, keeled ; lemma often ciliate on the back or margins, 

 1-o-nerved, the mid-nerve nearly always prolonged into a 

 slender awn; palea about equaling the lemma; grain free 

 within the lemma and palea. — Usually perennial grasses with 

 flat leaves and digitate spikes. (Named for Chloris, the god- 

 dess of flowers.) 



1. C. verticillata Nutt. Culms 1-4 dm. high, erect, or de- 

 cumbent and rooting at the nodes ; sheaths compressed ; leaves 

 obtuse, light green ; spikes several in 1-3 whorls, slender, 

 5-10 cm. long; spikelets 3 mm. long, with awns about 5 mm. 

 long; sterile lemma one. — Prairies, b. Kan. and southwestw. June. — At 

 maturity the inflorescence breaks away and forms a tumbleweed. Pig. 136. 



136. C. verticillata. 

 Spikelet x 2. 



54. BOUTELOtTA Lag. Mesquite Grass 



Spikelets 1-2-flowered, crowded and sessile in 2 rows along one side of a con- 

 tinuous flattened rhachis, which usually projects beyond the spikelets ; rhachilla 

 prolonged beyond the perfect floret and bearing a sterile (rarely staminate) 

 floret, a second or third rudiment often present ; glumes unequal, keeled ; lemma 

 broader, .S-5-nerved, 3-5-toothed or cleft, 3 of the divisions usually awn-pointed ; 

 palea about the length of the lemma, bidentate, the 2 keels scabrous ; sterile 

 floret sometimes reduced to the awns, rarely obsolete. — Our species perennial 

 with narrow flat or convolute leaves, and unilateral spikes nearly sessile along 

 a common axis. (Named for Glaudio Boutelou, a Spanish writer upon flori- 

 culture and agriculture.) 



gray's JIANUAL™ 10 



