Avena.1 LXXXIX. GRAMINE^E. 523 



regions of both hemispheres, or in the higher mountains within the 

 tropics. 



Annual. Spikelets hanging, 8 to 10 lines long . . . . . 1. A. fatua. 

 Perennial. Spikelets erect or spreading. 



Spikelets about 6 lines long 2. A. pratensis. 



Spikelets about 3 lines long 3. A. Jiavescens. 



1. A. fatua, Linn. (fig. 1198). Wild 0. — An erect, glabrous annual, 

 2 to 3 feet high, with a loose panicle of large spikelets, hanging from 

 filiform pedicels of unequal length, arranged in alternate bunches along 

 the main axis. Outer glumes nearly f inch long, pale-green or purplish, 

 tapering to a thin, scarious point. Flowering glumes 2 or 3, scarcely so 

 long as the outer ones, of a firm texture at the base, and covered out- 

 side with long, brown hairs, thin and cleft at the top, each lobe taper- 

 ing into a short point. Awn fully twice as long as the spikelet, twisted 

 at the base, abruptly bent about the middle. 



A common weed of cultivation in all corn countries, and generally 

 confined to cornfields, so that its origin is as yet doubtful, but probably 

 a native of the east Mediterranean region. Abundant in Britain. Fl. 

 with the com. A variety with the flowering glumes larger and more 

 like the outer ones, hairy only below the middle, and terminating in 2 

 almost awn-like points, has been distinguished as A. strigosa, Schreb., 

 and it is said that the cultivated Oat is but a variety of the same 

 species, readily degenerating into the wild form. This, however, 

 requires proof. 



2. A. pratensis, Linn. (fig. 1199). Perennial 0. — An erect peren- 

 nial, with a tufted or shortly creeping rootstock, 1 to 1J feet high, 

 with narrow leaves in dry pastures, but in rich mountain meadows 

 attaining often 3 feet high, the leaves then broader, with much flat- 

 tened sheaths. Panicle either slightly compound or reduced to a 

 simple raceme. Spikelets erect, usually 3 or 4-flowered, glabrous and 

 shining. Glumes all scarious at the top ; the outermost empty one 

 about 6 lines long, tapering to a point ; the second similar but rather 

 longer ; the flowering ones gradually smaller, shortly cleft at the point, 

 with an awn on the back fully twice their length. 



In meadows and pastures, especially in hilly districts, throughout 

 Europe and Kussian Asia, except the extreme north. Widely distri- 

 buted over Britain, but not very common. Fl. summer, rather early. 

 A. alpina, Sm., is a luxuriant mountain form, with more or less flat- 

 tened sheaths to the leaves, formerly confounded with the Continental 

 A. planiculmis, Schrad. A more marked variety, not uncommon in dry 

 districts, is A. pubescens, Huds. ; it has the leaf -sheaths more or less 

 downy, rather smaller spikelets, and the hairs on the axis of the spike- 

 let between the florets much longer. 



3. A. flavescens, Linn. (fig. 1200). Yellow 0. — An erect perennial, 

 1 to 2 feet high. Panicle oblong, 3 to 5 inches long, with slender, 

 somewhat spreading branches and pedicels. Spikelets erect, shining, 

 and often of a yellowish hue, not half the size of those of A. pratensis. 

 Glumes all scarious, the 2 outer empty ones very unequal. Flowering 

 glumes usually 4 or 5, cleft into 2 points ; the awn twisted and bent as 

 in the last two species, but short, and very fine and hair-like. Trisetum 

 jlavescens, Beauv. 



In rather dry meadows and pastures, in temperate and southern 



