580 cnAMiNK,!;. ((;u.vss iamii.y.) 



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

 nuiinu'iitinv. ('rripsacmn cvliMdricuni, Muhx.) — Dry sandy soil, Florida. 

 July -Sept. — Culms \°-2° \\\\i,\\. Spikes 2'-G' long, 1" iu diameter, purplish. 



54. MANISURIS, L. 



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

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

 sjjathe-likc .sheaths. Spikelets 1 -flowered, placed one at each end of the joints 

 of the sjjike ; the upper neutral, compressed, of two nearly ctpial hispid mem- 

 branaceous plumes ; the lower perfect, globose. Glumes coriaceous, concave, 

 tiie lower reticulated, the upper smootii. Talea! 2, hyaline. Stamens 3. Grain 

 included. 



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

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

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

 2° high. 



55. TRIPSACUM, L. Gama-Grass. 



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

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

 staminate, the lower fertile, 2-flowercd. Staminate flowers by pairs on each 

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

 palea; 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 upper pistillate, both 

 with hyaline palea;. Anthers opening by terminal jjores. Stigmas elongated. 

 Grain free. 



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

 Sept. — Culms erect, from tufted creeping rootstocks, 3° - 5° high. Leaves 1' 

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

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



56. ANDROPOGON, L. Bkoom-Grass. 



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

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

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

 them pedicelled and staminate, neutral, or rudimentary ; the other sessile, 2- 

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

 2 palea;, mostly perfect, shorter than the herbaceous or chartaceous glumes, the 

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



§ 1. A.^T>B,OVOGO^ V-ROvis.^. — Upper flower perfect. 



* Peduncle solitary, hearincj a single spike. 



\ A. Nuttallii. Culms (3° -4° high) straight, smooth, like the long 

 linear leaves ; spikes rigid, long-pedunclcd, the rachis and pedicel of the sterile 



