GRAMINEAB (GRASS FAMILY) 



39 



as follows: The two empty glumes are merely the glumes; the flowering glume 

 is the lemma; the additional glume in the Paniceae (the so-called third glume) 

 is the sterile lemma; palet and lodicule are used as heretofore. 



Key to the Tribes * 



Soikelets falling from the pedicels entire; naked or inclosed in 



bristles or bur-like involucres, 1-flowered, or if 2-flowered 



the iowerflower staminate; no upper empty lemmas; ra- 



chillai not extending above the sterile lemma. 



Spikelets round or somewhat compressed dorsally; glumes 



manifest;' hilum punctiform. 



Lemma and pal^ hyalirie, thin, much more delicate in 



texture than the glumes. - 



Spikelets in pairs, one sessile and the other pedicellate 



Spikelets not in pairs {Alopecur%£8, Polypogon, Cinna; 



etc.) . . 



Lemma, at least that of the perfect'fiower, similar Ih tex- 

 ture to the glumes, or thicker and firmer, never hya- 

 . line and thim^ -j ' ^' 



Lemma and palet membranous; the first glume usually 

 larger than the rest '. - « wO^t*- '■ ^.' . ^ i' ^ 



Lemma and palet chartaceous to coriaceous, very. dif- 

 ferent in color and appearance from the glumes. 

 Spikelets much compressed laterally; glumes none or rudi- 

 mentary; hilum linear . . . ' . - . 

 Spikelets with the flumes persistent, the rachilla articulated 

 above them, 1 -many-flowered; frequently the upper 

 lemmas are empty; rachilla often produced. beyond the 

 sterile lemma. 

 Spikelets borne in an open or spike-like panicle or raceme, 

 usually upon distinct pedicels. 

 Spikelets. 1-fiowered. 



Glumes 4; palet 1-nerved ■, i n ■...<'. ■ . ' . 



Glumes 2, rarely 1; palet 2-nerved (except in Cinna) 



Spikelets 2-many-flowered. ■ '■ •■'!! ■ ■ 



Lemma usually shorter than the glumes; - the Awn 



dorsal and:, usually bent 



Lemma. usually longer than the glumes; the awn termi- 

 nal and straight (rarely dorsal in Bromua) or none 



Spikelets in two rows, sessile or nearly so. 



Spikelets;on one side of the continuous axis, formingione- 

 sided spikes . . . .' .I'u '. ■ ' . ■' '.' 

 Spikelets alternately on opposite sides of the axis, which.! 

 ia often articulated ...... 



Tribe L Andropogoneae, 



Tribe VL Agrostideae. 



Tribe IL Zoysieae. 



Tribe III. Paniceae. 



Tribe IV. Oryzeae. 



Tribe V. Phalarideae. 

 Tribe VI. Agrostideae. 



Tribe VII; Aveneae. 

 Tribe DC. Festuceae. 



Tribe VIII. Ghlorideae. 

 Tribe X. Hordeae. 



^j Tribe I. AHDROPOGONEAE 



Rachis-internodes not sulcate; branches of the simple panicle paired, 

 or rarely single or,.variously branched. '-' 



Some or all of the racemes sessile j ■ . . . '. ' . . 1. Andropogon. 

 All of the racemes more or less peduncled. 



Pedjoellate spikelets wanting 3. Sorghastrum. 



Pedicellate spikelets present and usually staminate . .4. Sorghum. 

 Rachis-internodes sulcate . . '."■"'. '. .' . . 2. Amphilophis, 



Tribe II. ZOYSIEAE 



Inflorescence in termirial spikes 



6. Hilaria. 



* This excellent key fo the tribes represented in our range is taken without change (except 

 in terms used), from Uydberg's Flora of Colorado. The..generic keys have been adapted 

 from those of Rydberg s Fl. Colo.; Piper's Fl. Wash.; and Britten's Man. 



