58 GRAMINEAE. 13. Panicum. 



13. PANICUM, L. 



(Latin name of Millet (P. miliaceum), the grain of which was mixed with bread (panis) 



in early times.) 



Spikelets with 1 fertile bisexual flower and occasionally a male one below it, usually 

 paniculate ; outer glumes 3, the 1st smaller than the others, the 3rd sometimes enclosing 

 a palea or male flower ; flowering glume and palea usually almost equal, hard, smooth 

 or wrinkled, usually whitish, sometimes dark-colored. 



A. Spikelets glabrous or almost so. 



B. Lowest glume not half as long as spikelet. 



C. Panicle-branches alternate, simple or almost so P. adspersum 1. 



C. Panicle -branches simple, spike-like. 



D. Spikes clustered at top of stem P. sanguinale 2. 



D. Spikes alternate along stem. 



Spikes finally deflexed P. distachyum 3. 



Spikes erect P. helopus 14. 



C. Panicle -branches divided, long and slender ; lowest 



glume truncate P. decomposition 4. 



B. Lowest glume at least half as long as the spikelet. 

 E. Panicle large, its branches divided. 



F. Leaves glabrous ; lowest glume obtuse P. prolutum 5. 



F. Leaves more or less hairy P. effusum 6. 



E. Panicle-branches simple, spike-like. 



G. Panicle rather long. 



Spikes deflexed P. reversum 7. 



Spikes erect P. gracile 8. 



G. Panicle very short P. pauciflorum 9. 



A. Spikelets hairy. 



H. Panicle -branches long, divided ; spikelets silky. 



Spikelets ovoid, 2£ mm. long P. divaricatissimum 10. 



Spikelets oblong, 4 mm. long P. coenicolum 11. 



H. Panicle -branches short, spike-like. 



I. Spikes erect ; spikelets silky P. leucophaeum 12. 



I. Spikes somewhat spreading ; spikelets more or less 

 hairy. 

 J. Spikes slender, not bristly. 



3rd glume without long hairs ; spikelets often 



glabrous P. helopus 13. 



3rd glume ciliate with long hairs P. Gilesii 14. 



J. Spikes broad, bristly P. crus-galli 15 



1. P. adspersum, Trim Glabrous except the ciliate nodes ; leaves flat, broad at base , 

 ligule short, ciliate ; panicle narrow, its branches scarcely divided : lower spikelets 

 clustered, upper ones solitary and sessile ; spikelets acute, 3-4 mm. long ; lowest glume 

 1 mm. long, 1-3-nerved ; 2nd and 3rd glumes nearly equal, 5-7-nerved, the 3rd with a long 

 palea ; fruiting glume rugose, with a minute point. 



Only known from Bentham's record, " near Lake Eyre." 



*2. P. sanguinale, L. Summer Grass ; Crab Grass. Annual, with stems often creeping 

 and rooting ; leaves usually sprinkled with hairs ; ligule short, jagged ; spikes digitate 

 or approximate at the summit of the stem, 3-10, slender, 5-15 cm. long ; spikelets in 

 pairs on unequal pedicels, 3 mm. long, lowest glume minute ; the 2nd 3-nerved, half as 

 long as the 3rd, which is 7-nerved and ciliate ; fruiting glume smooth. 



Mostly in cultivated land and probably introduced here ; almost cosmopolitan. Dec. - 

 Mar. 



3. P. distachyum, L. Glabrous perennial with flat leaves and short, ciliate ligule ; 

 spikes few, distant, finally deflexed or spreading, 2-5 cm. long, bearing the alternate 

 spikelets in 2 rows along one side of the rhachis ; spikelets 5 mm. long, acute ; lowest 

 glume broad, not half as long as the spikelet ; 2nd and 3rd glumes equal, 3-nerved ; 

 fruiting glume 3-nerved, transversely and finely rugose. 



Far North. Flowering chiefly in summer. 



4. P. decompositum, R. Br. Perennial, glabrous or with long spreading hairs on the 

 main rhachis and upper leaf-sheaths ; ligule short, ciliate ; panicle rather large, at first 

 compact, afterwards loose and spreading, with numerous slender divided branches, 

 the lower ones clustered, or alternate and distant ; spikelets on capillary pedicels, 

 acuminate, 3 mm. long, often purplish ; lowest glume truncate, barely | the length of 



