PANICUM.] GRAMINE^. 469 



Spikelets very many-fld. Fl. glumes convex, obtuse, tip 



nerveless, awnless 39. Glyceria. 



Spikelets panicled or spicate. Fl. glumes convex, tip nerved 



acute or awned. Ovary glabrous 40. Festuca. 



Spikelets panicled, many-fld Fl. glumes convex. Ovary tip villous. 



41. Bromus. 

 Spikelets racemed or spicate. Fl. glumes convex. Ovary tip villous. 



42. Brachypodium. 



TEIBE VIII. HORDEE'JE. SpiJcelets 1- or more-fld., sessile in the 

 notches of a simple rachis ; rachilla produced beyond the uppermost fl. 

 glume (except in Nardus). Fl. glume with a terminal awn or 0. 



SUB-TRIBE 1. Triticeae. Spikelets solitary in the notches, 3- or more-fd. 



Spikelets many-fld., with their sides to the rachis 43. Lolium. 



Spikelets many-fld., with their faces to the rachis 44. Agropyrum. 



SUB-TRIBE 2. Lepturese. Spikes solitary in the notches, 1-2-jld. 



Empty glumes 1-3. Spikelets distichous 45. Lepturus. 



Empty glumes 0. Spikelets secund. Style long 46. Nardus. 



SUB-TRIBE 3. Elymese, Spikelets 2 or more in each notch, collateral ; 

 the central perfect ; the lateral perfect or reduced to bristles. 



Spikelets 1-fld 47. Hordeum. 



Spikelets 2-6-fld 48. Elymus. 



I. PA'NICUM, L. 



SpiJcelets without bristles at the base, or with slender hairs only, spiked 

 racemed or panicled, 1-fld., or if 2-fld. the lower male. Empty glumes 2 

 in the 2-fld. spikelets, 3 in the 1-fld. ; lowest small or minute, 2d larger, 

 strongly nerved. Fl. glume nerved, hardening and en-closing the palea 

 and fruit. Scales 2, fleshy, truncate. Stamens 3. Ovary glabrous ; stigmas 

 penicillate, shorter than the styles. Fruit compressed or plano-convex. 

 DISTRIB. Chiefly tropical ; species 270. ETYM. The Latin name. 



SECTION 1. Digita'ria, Scop. (gen.). Spikelets unilateral, on digitate 

 spikes. Flowering glume not awned. 



P. gla'brum, Gaud. ; spikes about 3, spikelets 1-fld. Digita'ria 



humifu'sa, Pers. ; D. Jilifor'mis, Koch. 



Sandy soil in the S.E. counties, from Norfolk to Hants, local; fl. July- Aug. 

 Annual. Hoot fibrous. Stems 6-12 in., prostrate or decumbent. Leaves 

 narrow, flat; sheaths flat, mouth hairy; ligule short. Spikes 2-3 in., 

 flexuous, channelled on the face. Spikelets ^ in., in pedicelled pairs, plano- 

 convex, elliptic, purplish ; empty glumes hairy, lower minute appressed or 

 0. DISTRIB. Most warm climates. 



SECTION 2. Echinochlo'a, Beauv. (gen.). Spikelets in racemes or 

 panicles. Flowering glume awned or pointed. 



P. CIIUS-GAL'LI, L. ; spikelets panicled 1-fld. 



