1 7 8 



GRAMINEAE. 



50. CHLORIS Sw. Prodr. 25. 1788. 



Mostly perennial grasses with flat leaves and spicate inflorescence, the spikes solitary, 

 few, or numerous and verticillate or approximate. Spikelets i-flowered, arranged in two 

 rows on one side of the rachis. Scales 4; the 2 lower empty, unequal, keeled, acute; third 

 and fourth usually awned, the former subtending a perfect flower; palet folded and 2-keeled. 

 Stamens 3. Styles distinct. Stigmas plumose. Grain free, enclosed in the scale. [Greek, 

 greenish-yellow, referring to the color of the herbage.] 



About forty species, mostly natives of warm and tropical regions. Besides the following some 

 10 others occur in the southern United States. 



i. Chloris verticillata Nutt. Prairie 

 Chloris. (Fig. 407.) 



Chloris verticillata Nutt. Trans. Am. Phil. Soc. (II.) 

 5: 150. 1833-37. 



Culms 6 / -i8 / tall, erect, or decumbent and root- 

 ing at the lower nodes, smooth, glabrous. Sheaths 

 shorter than the internodes, smooth, or roughish at 

 the summit; ligule a ring of short hairs; leaves 1'-$' 

 long, i // -2 // wide, obtuse, often apiculate, scabrous; 

 spikes slender, usually spreading, 2'-4*4' long, in 

 one or two whorls, or the upper ones approximate; 

 spikelets, exclusive of the awns, about ~i l / 2 " long, 

 the first scale about one-half the length of the sec- 



ond ; the third T " lon S> obtuse > ciliate on the 

 nerves, especially on the lateral ones, bearing just 

 below the apex a scabrous awn about 2 - ^ // long; 

 fourth scale as long as or shorter than the third, 

 awned near the usually truncate apex. 

 On prairies, Kansas to Texas. May-July. 



51. GYMNOPOGON Beauv. Agrost. 41. pi. 9. /. 3. 1812. 



Perennial grasses with flat and usually short rigid leaves, and numerous slender alter- 

 nate spikes. Spikelets i-flowered, almost sessile, the rachilla extended and bearing a small 

 scale which is usually awned. Scales 3 or 4; the 2 lower empty, unequal, narrow, acute; 

 third broader, fertile, 3-nerved, slightly 2-toothed at the apex, bearing an erect awn; the 

 fourth empty, small, awned; palet 2-keeled. Stamens 3. Styles distinct. Stigmas plumose. 

 Grain linear, free, enclosed in the rigid scale. [Greek, naked-beard, referring to the pro- 

 longation of the rachilla.] 



Six known species, all but one of them natives of America. 



Spikes bearing spikelets their whole length; awn longer than flowering scale. i. G. ambiguus. 

 Spikes bearing spikelets above the middle ; awn shorter than flowering scale. 2. G. brevifolius. 





i. Gymnopogon ambiguus (Michx.) B.S.P. 



(Fig. 408.) 



Andropogon ambiguus Michx. Fl. Bor. Am. i: 58. 



1803. 



Gymnopogon racemosus Beauv. Agrost. 164. 1812. 

 Gymnopogon ambiguus B.S.P. Prel. Cat. N. Y. 69. 



1888. 



Culms !2 / -i8 / tall, erect, or decumbent at the 

 base, simple or sometimes sparingly branched, 

 smooth and glabrous. Sheaths short, glabrous, 

 excepting a villous ring at the summit, crowded at 

 the base of the culm; ligule very short; leaves i'- 

 4' long, 2 // -6 // wide, lanceolate, acute, cordate at 

 the base, spreading, smooth or a little scabrous 

 above; spikes slender, spikelet-bearing throughout 

 their entire length, at first erect, the lower 4 / -8 / 

 long, at length widely spreading; spikelets, exclu- 

 sive of awns, 2"-2X" long; first scale shorter than 

 the second; third scale exceeded by the second, the 

 callus at the base hairy, the awn 2 // ~3 // long. 

 ?" In dry sandy soil, southern New Jersey to Missouri, 

 south to Florida and Texas. Aug. -Oct. 



Broad-leaved Gymnojpogon. 



