GRAMINE.V.. (grass FAMILY.) 591 



2. R. COrrugata, Baldw. Culm stout, compressed ; peduucles mostly 

 single ; spikes slightly compressed, erect ; lower glume longitudinally grooved 

 ^nd somewhat reticulated, ovate ; sterile flower staminate. — Low pine barrens, 

 Georgia and Florida, near the coast. Sept. - Oct. — Culm 2° - 4° high. Spikes 

 4' - 6' long, 2" in diameter, purplish. 



3. R. cylindrica, Cliapm. Culm slender, terete ; leaves narrowly lin- 

 ear ; peduncles single, elongated ; spikes slender, terete, mostly curved ; spike- 

 lets as long as the joint ; lower glume ovate, obtuse, obscurely pitted in lines ; 

 sterile spikelet rudimentary. — Ury sandy soil, Florida, and westward. July - 

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



18. MANISUKIS, L. 



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

 Spikes lateral and terminal, jointed, the short peduncles enclosed in spathe- 

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

 spike ; the upper neutral, compressed, of two nearly equal membranaceous 

 glumes ; the low^er perfect, globose. Glumes coriaceous, concave, tlie lower 

 reticulated. Palet 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 pastures. August - Sept. Introduced. — Culms ]°-2° high. 



19. TRIPSACUM, L. Gama Grass. 



Tall perennial grasses, with solid culms, broad and flat leaves, and spiked 

 inflorescence. Spikes jointed. Spikelets 2-flowered, the upper ones staminate, 

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

 gular pint of the sleuder rachis, 3-androus; glumes 2', coriaceous ; palese hya- 

 line. Pistillate spikelets single, embedded in a deep excavation of tlie thick 

 and polished joints ; the outer glume cartilaginous, concave, the inner mem- 

 branaceous, boat-shaped ; lower flower neutral, tlie upper pistillate, both with 

 hyaline paleaB. Anthers opening by terminal pores. Stigmas elongated. 

 Grain free. 



1. T. daetyloides, L. Culms erect, .3° -6° high; leaves 2° -3° long, 

 1' wide ; sjjikes 1 -3, 4' -8' long, on long lateral and terminal peduncles, the 

 fertile joints 3-5, angular, or, in var. monostachyum, several and terete. — 

 Dry rich soil, common. 



2. T. Floridanum, Porter. Culms more slender, 2° - 4° high ; leaves 

 narrower and more rigid ; spikes single, 6' - 10' long, erect ; the joints shorter ; 

 spikelets smaller, 2-ranked. — Florida, and westward. 



20. ELIONURUS, HBK. 



Tall erect perennial grasses, with the inflorescence of Andropogon, but the 

 awnless spikelets borne alternately on two sides of the slender flexuous rachis, 

 forming a solitary long-peduncled villous spike. 



1. E. tripsacoides, HBK. Culms (3° -4° high) straiglit, smooth like 

 the long linear leaves ; spikes long-peduncled, the rachis and pedicel of the 

 sterile flower fringed with closely appressed white hairs ; s])ikelets awnless ; 



