n6 



GRAMINEAE. 



Vol. I. 



with a pedicel, staminate, empty, or reduced to a single scale, or sometimes wanting. Perfect 

 spikelet consisting of 4 scales, the outermost coriaceous, 2-keeled, the second keeled and 

 acute, the two inner hyaline, the fourth more or less awned and subtending a palet and 

 perfect flower. Stamens 1-3. Grain free. [Greek, in allusion to the bearded rachis.] 



About 150 species, widely distributed in tropical and temperate regions. Besides the following, 

 some 25 others in southern and western North America Type species : Andropogon hirtum L. 



Pedicellate spikelets empty, of 1 or 2 scales, much smaller than the sessile spikelets, or wanting. 

 Stamen 1 ; racemes, or some of them, included in the spathes ; rachis internodes slender. 

 Sheaths at the upper part of the culm not enlarged ; racemes equally exserted. 



Inflorescence oblong; branches divided into corymbiform masses. 1. A. glomeratus. 

 Inflorescence long, linear, little divided, not corymbiform. 2. A. virginicus. 



Sheaths at the summit or upper part of the stem much enlarged ; racemes on one of the 

 branches exserted much beyond the others. 3. A. Elliottii. 



Stamens 3 ; racemes usually exserted beyond the spathes ; rachis internodes stouter. 



Intercarinal space of the first scale of the sessile spikelet nearly nerveless ; terminal hairs 



of the internodes about twice their length. 4. A. ternarius. 



Intercarinal space with 2 or 3 nerves running the length of the scale ; terminal hairs of the 

 internodes about equaling them in length. 5. A. Cabanisii. 



Pedicellate spikelets staminate, of 3 or 4 scales, equaling or exceeding the sessile spikelets. 

 Rachis internodes copiously pubescent with long hairs. 



Awn perfect, with a defined column ; culms tufted, or with short rootstocks. 



Sessile spikelets hispidulous ; rachis hairs 1" long or less. 6. A. furcatus. 



Sessile spikelets mostly glabrous; rachis hairs i^>"-2" long, yellow. 7. A. chrysocomus. 

 Awn imperfect, rarely spiral at the base ; rootstocks long, horizontal. 8. A. Hallii. 

 Rachis internodes glabrous, or with a few weak crimped hairs. 9. A. paucipilus. 



i. Andropogon glomeratus (Walt.) B. S. P. 

 Bushy Beard-grass. Fig. 264. 



Cinna glomerata Walt. Fl. Car. 59. 1788. 



Andropogon macrourum Michx. Fl. Bor. Am. 1 ; 56. 1803. 



Andropogon glomeratus B. S. P. Prel. Cat. N. Y. 67. 1888. 



Andropogon corymbosus Nash, in Britton, Man. 70. 1901. 



Culms erect, ii°-3° tall, smooth, simple below, much 

 branched above, upper nodes of branches barbed; 

 sheaths compressed, scabrous, glabrous or pubescent ; 

 leaves I "-2 J" wide, scabrous, long-acuminate, the basal 

 two-thirds as long as to equalling the culm, those of the 

 culm 6'-i2' long; branches elongated, forming a com- 

 pact terminal inflorescence ; racemes in pairs, io"-is" 

 long, loose, protruding from the side or exserted from 

 the apex of the scabrous spathes; rachis flexuous, the 

 joints and pedicels pubescent with long spreading silky 

 hairs; outermost scale of sessile spikelet about 2"-2i" 

 long ; awn 6"-o/' long, scabrous ; pedicelled spikelet re- 

 duced to a single scale or wanting. 



Damp soil, Nantucket to southern New York, south to 

 Florida and Mississippi. Sept.-Oct. Indian Beard-grass, 

 Brook-grass, Bushy Blue-stem. 



2. Andropogon virginicus L. Virginia 

 Beard-grass. Broom-sedge. Fig. 265. 



Andropogon virginicus L. Sp. PI. 1046. 1753. 



Cinna lateralis Walt. Fl. Car. 59. 1788. 



A. dissitifiorus Michx. Fl. Bor. Am. 1 : 57. 1803. 



A. vaginatus Ell. Bot. S. C. & Ga. 1 : 148. 1817. 



A. tetrastachyus Ell. Bot. S. C. & Ga. 1: 150. 1817. 



Culms erect, smooth, ii°-4° tall, simple at base, 

 branching above; sheaths, at least the lower, more 

 or less hirsute; blades 6'-ii° long, i"-3" wide, 

 long-acuminate, scabrous on the margins, usually 

 hirsute above; branches of culm short, forming 

 a loose and elongated inflorescence ; racemes in 

 pairs, occasionally 3 or 4, io"-3o" long, loose, 

 protruding from the side of the spathes, 

 the rachis flexuous, slender, the joints and pedicels 

 pubescent with long spreading silky hairs ; outer- 

 most scale of sessile spikelet ii"-2" long; awn 

 4"~9" long, straight, scabrous; pedicellate spike- 

 let generally wanting, occasionally a rudimentary 

 scale present. 



In dry or moist fields, Massachusetts to Illinois, 

 Florida and Texas; in the Bermudas, Bahamas and 

 tropical America. Aug.-Sept. 



