580 GRA-MINE^. (grass FAMILY.) 



the joint ; lower glume ovate, obtuse, obscurely pitted in lines ; sterile spikelct 

 ruiliiiK'Tiiiuy. (Tiipsacum cylindricum, Michx.) — Dry sandy soil, Florida. 

 July - Sept. — Culms 1° - 2° high. Spikes 2' - 6' long, 1 " iu diameter, purplish. 



54. MANISUmS, L. 



Annual grasses, with branching culms, flat leaves, and spiked inflorescence. 

 Spikes lateral and terminal, clustered, jointed, the short jieduiiclcs enclosed in 

 spathe-likc sheaths. Spikelets l-flo\vcrcd, placed one at each end of the joints 

 of the spike ; the upper neutral, compressed, of two nearly equal his])id mem- 

 branaceous glumes ; the lower perfect, globose. Glumes coriaceous, conciive, 

 the lower reticulated, the upper smooth. Palcaj 2, hyaline. Stamens 3. Grain 

 included. 



1. M. granularis, Swartz. Leaves linear-lanceolate, and, like the sheaths, 

 hairy; spikes 6"- 10" long; spikelets minute, turning black. — Fields and pas- 

 tures, Florida to South Carolina. Aug. and Sept. Introduced. — Culms 1°- 

 2° high. 



55. TRIPSACUM, L. Gama-Grass. 



A tall perennial grass, with solid culms, broad and flat leaves, and spiked 

 inflorescence. Spikelets awnless, monoecious, in jointed spikes, the upper ones 

 stamiiiate, the lower fertile, 2-flowered. Staminate flowers by pairs on each 

 short triangular joint of the slender rachis, 3-androus ; glumes 2, coriaceous ; 

 palca; hyaline. Pistillate spikelets single, embedded in a deep excavation of 

 the thick and polished joints; the outer glume cartilaginous, concave, the inner 

 membranaceous, boat-shaped ; lower flower neutral, the u])pcr pistillate, both 

 with hyaline paleoe. Anthers opening by terminal i)orcs. Stigmas elongated. 

 Grain free. 



1. T. dactyloides, L. — Rich soil, Florida, and northward. Aug. and 

 Sept. — Culms erect, from tufted creeping rootstocks, 3°-.")° high. Leaves 1' 

 wide. Spikes 4' - 8' long, on long lateral and terminal peduncles, 2-4 in a 

 cluster or sometimes solitaiy. (T. monostachyum, Wilkl.) 



56. ANDROPOGON, L. Buoom-Gkass 



Coarse perennial grasses, with branching erect culms, long and harsh leaves, 

 and spiked inflorescence. Spikes lateral and termiiud, jointed. Spikelets by 

 pairs on each joint of the slender commonly hairy or plumose rachis ; one of 

 them pcdicellcd and staminate, neutral, or rudimentary ; tiie other sessile, 2- 

 flowered, the lower flower consisting of one palea, and neutral ; tiie upper of 

 2 palcflc, mostly perfect, shorter than the herbaceous or chartaci ons glnmes, the 

 lower one mostly awno<l at the apex (except No. 1 ). Stamens 1 - 3. Grain free. 



^ 1. ANDKOPOGON Proper. — r;/Y)pr/ouw;>rr/;r/. 

 * Prdnncle solitary, bcarinf) a single spike. 

 I. A. Nuttallii. Culms (3° -4° liigh) straight, smoofli, like the long 

 linear leaves ; spikes rigid, long-pedunded, the rachis and pedicel of iho stcrilo- 



