610 THE GKASS FAMILY. [Panicum. 



flat, and 5-nerved. Flowering glume, about the same length, very 

 smooth and awnless. Digitaria sanguincdis, Scop. 



One of the commonest weeds in all tropical and warm countries, be- 

 coming less frequent in central Europe. In Britain, only as an intro- 

 duced weed of cultivation in the south of England. Fl. the whole season. 



2. P. glabrum, Gaud. (fig. 1161). Glabrous P. Very much like P. 

 sanguinale, but a much smaller plant ; the panicle has only 2 or 3 spike- 

 like branches, each scarcely above an inch long, and the spikelets are 

 fewer. The first glume is, as in the last species, very minute, but the two 

 next empty ones are both about the same length as the flowering 

 glume. Digitaria humifusa, Pers. 



A weed of warm climates, like the last, but rather less tropical, more 

 generally spread over central Europe, extending northward to southern 

 Scandinavia, and better established in the south of England. Fl. 

 summer and autumn. 



3. P. verticillatum, Linn. (fig. 1162). Hough P. A glabrous erect 

 annual, 1 to 2 feet high, with flat leaves, rough on the edges. Spikelets 

 small, crowded into a cylindrical but rather loose, compound spike (or 

 rather, spike like panicle), 1 to 2 lines long, interspersed with numerous 

 bristles, 2 or 3 lines long, inserted under the spikelets, but projecting be- 

 yond them. These are rough with minute hairs, reversed so as to cling 

 to the hand when the spike is drawn downwards through the fingers. 

 First glume very small, the two next about the length of the flowering 

 one. Setaria verticillata, Beauv. 



In cultivated and waste places, very common in southern Euope, and 

 generally spread over central Europe to the Baltic, and into Asia, but 

 much rarer in hot countries than the two following species. In 

 Britain, it occurs in the south and east of England. Fl. summer and 

 autumn. 



4. P. glaucum, Linn. (fig. 1163). Glaucous P. An erect annual, 

 very much like P. verticillatum, but of a paler green ; the spike or spike- 

 like panicle more compact and regularly cylindrical, 1 to 1 inches long, 

 with very numerous projecting bristles. These are but slightly rough 

 with minute erect teeth, so as only to be felt as the spike is pushed 

 upwards through the fingers. Spikelets rather larger than in P. verticil- 

 latum, the second glume rather shorter than the third, the flowering 

 one marked with numerous transverse wrinkles, visible especially as the 

 seed ripens. Setaria glauca, Beauv. 



One of the commonest weeds of cultivation throughout the warmer 

 regions of the globe, abundant in southern Europe, less so in central 

 Europe, not extending into Scandinavia. In Britain, only occasionally 

 introduced. Fl. all summer and autumn. 



5. P. viride, Linn. (fig. 1164). Green P. Closely resembles P. glau- 

 cum, but the second and third glumes are both about the same length, 

 and the flowering one has no transverse wrinkles. Setaria viridis, 

 Beauv. 



With the same geographical range as P. glaucum, this is, however, 

 much less common in tropical countries, but more so in central Europe, 

 extending eastward all across Asia, and northward into southern Scan- 

 dinavia. In Britain, it is also rather better established than the other 

 species, except P. glaucum. Fl. summer and autumn. 



6. P. Crus-galli, Linn. (fig. 1165). Oockspur P. A coarse, decum- 



