972 



THE GRASS FAMILY. 



2. Perennial Oat. Avena pratensis, Linn. (Fig. 1180.) 



(Eng. Bot. t. 1204.) 



An erect perennial, with a tufted or 

 shortly creeping rootstock, 1 to 1| feet 

 high with narrow leaves in dry pastures, 

 but in rich mountain meadows attaining 

 often 3 feet high, the leaves then broader, 

 with much flattened 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 outer- 

 most empty one about 6 lines long, ta- 

 pering to a point ; the second similar but 

 rather longer ; the flowering ones gra- 

 dually 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 

 Hussian Asia, except the extreme north. 

 Widely distributed over Britain, but not 

 very common. Fl. summer, rather early. Luxuriant mountain speci- 

 mens, with more or less flattened sheaths to the leaves, have been dis- 

 tinguished as a species, under the name of A. alpina (A. planiculmis, 

 (Eng. Bot. t. 2141), or, when very luxuriant, as A. planiculmis (Eng. 

 Bot. Suppl. t. 2684). A more marked variety, not uncommon in dry, 

 limestone districts, is generally distinguished as the doivny O. (A. pu- 

 bescens, Eng. Bot. t. 1640). It has the leaf-sheaths more or less downy, 

 rather smaller spikelets, and the hairs on the axis of the spikelet be- 

 tween the florets much longer. 



Fig. 1180. 



3. Yellow Oat. Avena flavescens, Linn. (Fig. 1181.) 



(Eng. Bot. t. 9c 2. Trisetum, Bab. Man.) 



An erect perennial, 1 to 2 feet high. Panicle oblong, 3 to 5 inches 

 long, w^ith slender, somewhat spreading branches and pedicels. Spike- 

 lets erect, shining, and often of a yellowish hue, not half the size of 

 those of the perennial O. 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 tw T o species, but short, and very 

 fine and hair-like. 



