314 



j)ani('ulalc, consisting of spikclets composed of two to many •i-i-nnkcd 

 imbricated bracts (glumes), the two lowt^st noiiiially ('iii|)ty, one or 

 both of tliese sometimes wanting or vwy iniu-h I'cduccd. One or more 

 of tlie upper giuiiics cxcciil sdiiicl iincs the tci'iiiiual ones contains in tlie 

 axil a flower which is usually inclosed by the bract like palea. Flowi'rs 

 pei'l'ect or staminate. sometimes dioecious or monoecious, subtendi'd l)y I 

 to 3 minute hyaline scales (lodicnies). Stamens 1 to (i, usually 3; anthers 

 :2-celled, versatile. Ovary l-celled. l-o\uled; styles 1 to ;>. eonnnonly 2; 

 stigmas haii'y or ])lumose. Fruit a seed-like grain ( caryoi)sis). 



Genera about ;!3r) ; species about 3.-500, widely distributed in all ])arts 

 of the world, the greater numl)er of species being found in the Tropics 

 but tlie greater number of individuals being found in temperate regions.. 



KEY TO Till-; TKIIIKS AND OEN'KKA. 



1. Spikelets one, rarely two-flowered, lower flower when present 

 imperfect, falling from the pedicel entire or with certain joints 

 of the rhachis at maturity. Rhachilla not produced beyond 

 the flowers. 



2. Spikelets cylindrical or somewhat dorsally compressed ; 

 empty glumes manifest ; hilum punctiform. 



.3. Flowering glumes and palea hyaline, much more 

 delicate in structure than the thick-membranous 

 to cartilaginous empty glumes. 



4. Spikelets unisexual on separate inflores- 

 cences or on different parts of the same 



inflorescence I. Mayde/E 



4. Spikelets in pairs, one sessile, one pedicel- 

 late in the same inflorescence, the former 

 perfect, the latter staminate or empty, 



rarely perfect II. Andropogone.^ 



:!. ['^lowering glumes, at least of the perfect flower, 

 similar in texture to the empty glumes or fre- 

 quently thicker, never hyaline and thin. 



4. Flowering glume and palea membranous. 



."). Inflorescence spicate ; spikelets fall- 

 ing singly or in groups, the first 

 glume usually larger than the rest.. III. Zoisik.-^ 

 5. Inflorescence paniculate ; spikelets de- 

 ciduous singly from the ultimate 

 branchlets of the inflorescence, the 

 first glume usually smaller or nar- 

 rower than the rest IV. Thistkc.ine.?!; 



4. Flowering glume and palea chartaceous, cai- 

 tilaginous, or coriaceous, very different 

 in color and appearance from the empty 



glumes V. Panick.k 



2. Spikelets mu('h compressed laterally ; empty glumes none 



or rudimentary ; hilum linear VI. Or\7.k.v, 



I. Spikelets one to many flowered, the empty glumes persistent, 

 the rachilla generally articulated above the empty glumes 

 and produced beyond the upper glume, the upper glumes fre- 

 quently empty. 



2. Stems herbaceous; leaf-blades sossilo, not arlicuhitc<l with 

 the sheath. 



3. Spikelets pedicellate in panicles, spikc-likc panicles 

 or racemes. 



4. Spikelets one-flowered. 



.5. Empty glumes four ; palea one- 

 nerved Vll. PriALAIlIOEiE 



5. Rmpty glumes two; palea two-nerved., ^'lll. A<;i!o^TinE.T: 



