Panicum."] CLXXIII. GEAMINEJ:. (J. D. Hooker.) 27 



I smallest and fewest nerved; 1C. and III usually snbequal, 3- -nerved 

 obloug ovate or lanceolate ; III paleate or not, triandrons or neuter ; IV 

 paleate, bisexual, oblong ovate or lanceolate, hardened in fruit, glabrous, 

 dorsally convex ; palea 2-nerved, membranous or hardened in fruit. Lodi- 

 cules 2, cuneate or quadrate, rarely 0. Stamens 3, apically exserted. 

 Grain free within gl. IV and palea. Species very many ; all war^i 

 countries. 



Exceptions. In P. subeglume, gl. I and II are absent. In P. Crus-galli 

 gl. Ill is sometimes produced into a rigid Ion* or short awn. In P. not.abile, 

 wribiguum andjavanicum, gl. IV is crowned with a short awn that is concealed by 

 gls. II and III. 



Under Pospalum (p. 10), I have given my reasons for removing to that genus 

 the group Digitaria, which has hitherto been referred to Panic-urn ; those for 

 excluding Tricholcena and Ax^nopus will appear under the respective genera. 

 Ichnanthus is excluded on less satisfactory grounds. 



KEY TO THE SECTIONS. 



A. Spikelets terete or dorsally compressed. 



I. BrancUets of panicle not produced beyond the terminal spikelets into 

 awn-like bristles. 



Sect. I. PASPALOIDE.E. Spikelets 2-seriate, close-set on the under- 

 surface of the flat rachis of a simple spike, globose or ovoid ; awn ; gl. I 

 very small, IV more or less rugose. Perennials. Spikes alternate forming 

 a simple raceme. (Sp. 1-4) 



Sect. II. ECHINOCHLOA. Spikelets 3-4-seriate (2-seriate in P. notabile) 

 crowded on the undersurface ot' a simple or rarely branched spike, globose 

 or ovoid; gl. I half as long as III or shorter, II and III strongly nerved 

 cuspidate or rigidly awned, IV hard in fruit. Annuals. Spikes alternate 

 or crowded in usually a simple raceme. (Sp. 5-7.) 



Sect. III. BRACHIARTA. Spikelets irregularly 1-2- (rarely 3-) seriate on 

 the slender or spiciform branches of a simple raceme, solitary or geminate, 

 distant or crowded, ovoid or obovoid ; gl. I not balf as long as III (except 

 in jP. ambiguum), II and III subequal, awn 0, or IV with a very short awn 

 concealed by gls. II and III. (Sp. 8-18.) 



Sect. IV. HYMENACHNE. Spikelets small, crowded in spiciform panicles 

 (except P. auratum and curvatum) ovoid or lanceolate, sometimes decurvred ; 

 gls. usually strongly ribbed, I much shorter than III, IV usually much 

 shorter than III, narrow, white. (Sp. 19-25.) 



Most of the species of this section are very variable. 



Sect. V. BREVJGLUM^E. Spikelets very small, in pairs or fascicle^ on 

 the filiform branches of a lax panicle or simple rachis, dorsally much 

 compressed; gl. I and II both much shorter than IV, III and IV lanceo- 

 late. (Sp. 26, 27.) 



Sect. VI. EFFUSE. Spikelets solitary, rarely binate, sessile -or pedicelled 

 on the slender branches of a decompound usually open panicle. (See also 

 P. auratum and curvatum in Sect. Hymenachne.) (Sp. 28-47.) 



