398 GE AMINES. (GRASS FAMILY.) 



SERIES I. Spikelets articulated with the pedicel below the glumes, and consisting of one 

 fertile terminal flower, and usually an inferior one which is male or sterile. — Pact- 



CACEiE. 



Tribe I. Fertile spikelets perfect, rarely by abortion unisexual, spicate or paniculate : 

 outer glumes usually two, rarely one or none ; flowering glume indurated in fruit, or at 

 least more rigid than the outer ones, awnless. — Panice^e, 



* Branches of the simple panicle spike-like, or variously branched, not produced beyond 



the spikelets. 



1. Paspalum. Spikelets in one or two rows along one side of the solitary, subdigitate, or 



scattered flattened spikes. Glumes 3 (rarely 2), the two outer ones membranous, 

 equal, or sometimes the outer one smaller or disappearing : the flowering glume more 

 or less concave, becoming indurated, embracing the shorter palet, which is of the 

 same texture. 



2. Beckmannia* Spikelets subsessile, crowded in two rows upon the short simple or 



compound branches of a long narrow panicle. Glumes 3, sub-coriaceous, obovate or 

 boat-shape, compressed and inflated, empty : the flowering glume lanceolate, acute 

 or acuminate, of thinner texture. 

 S. Panicum. Spikelets spicate or paniculate. Glumes 3 (rarely 2), the two outer ones 

 empty and one of them smaller (often very small) than the other: fertile glume with 

 x its palets usually coriaceous in texture and obtuse or obtusish. 



4. Setaria. Spikelets in a cylindrical spike, or sometimes an interrupted panicle ; several 



bristles below the articulation of the spikelets, which are persistent after the fall of 

 the spikelets. Glumes 8 (rarely 2), the two outer ones empty and membranous, as is 

 also the lower flowering one : the flowering glume, with its palets, indurated and 

 striata 



* * Spikelets surrounded by or intermixed with abortive branches of the panicle, forming 



a bristly involucre, which ?s deciduous with the spikelet. 



5. Cenchxus. Spikelets enclosed 1 to 3 together in a coriaceous, spiny involucre or bur ; 



these arranged in an oblong or cylindrical panicle. 



* # * Spikes one to many on a common peduncle, rhachis produced beyond the uppermost 



spikelet 



6. Spartina. Spikelets one-flowered, much flattened, sessile along one side of the long 



triangular rhachis, or in racemose spikes. Outer glumes strongly compressed, with a 

 rigid keel, unequal, awnless : flowering glume membranaceous, compressed, carinate : 

 palet nearly equalling its glume, 2-keeled. 



Tritoe II. Spikelets usually perfect, or some of them imperfect, articulated in fascicles 



with the rhachis of the simple spike : flowering glumes membranaceous ; generally 



the outer or empty ones smaller and hyaline. — Zoysie^e. 



I. Hilaria. Inflorescence in terminal spikes. Spikelets in small clusters of three, closely 



sessile at the joints of the rhachis ; the central spikelet containing a single fertile 



flower, either female or perfect : the lateral spikelets each with 2 or 3 male flowers. 



Tribe III. Spikelets arranged along the rhachis of the spike or the branches of the 

 panicle generally in twos, or the terminal one in threes. Flowering glume hyaline, 

 smaller than the empty ones, often bearded. — Andropogone.,e. 



8. Andropogon. Inflorescence in simple or paniculate spikes. Spikelets in pairs in 



the alternate notches of the rhachis, one sessile and fertile, the other pedicelled and 

 sterile. 



9. Chrysopogron. Inflorescence loosely paniculate. Fertile spikelets one-flowered, ses- 



sile between two pedicellate sterile spikelets at the end of the slender branches of 

 the panicle, with sometimes 1 to 3 pairs of spikelets on the branch below the termi- 

 nal three. 



SERIES II. Spikelets usually not articulated with the pedicel below the glumes j the 

 rhachis continuous above the persistent lower glumes, and disarticulating with the 

 flowers or persisting ; consisting rarely of a single flower, or of one perfect and one or 



