590 THE GRASS FAMIIT. 



In meadows and pastures, especially in hilly districts, throughout Europe 

 and Russian Asia, except the extreme north. Widely distributed over Bri- 

 tain, but not very common. Fl. summer, rather early. Luxuriant moun- 

 tain specimens, with more or less flattened sheaths to the leaves, have been 

 distinguished 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, lime- 

 stone districts, is generally distinguished as the downy O. {A. pubescens, 

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

 smaller spikelets, and the hau-s on the axis of the spikelet between the florets 

 much longer. 



• 3. Yellow Oat. Avena flavescens, Liun. 



(Eng. Bot. t. 952. Trisetum, Bab. Man.) 

 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 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 two species, but short, and very fine and hair-like. 



In rather dry meadows and pastures, in temperate and southern Europe 

 and Russian Asia, extending northward into southern Scandinavia. Fre- 

 quent in England and Ireland, much less so in Scotland. Fl. summer. Like 

 the perennial O., it varies in the glabrous or hairy leaf-sheaths, and in the 

 length of the points of the glumes. 



XIX. FAXiSE-OAT. ARRHENATHERUM. 



A single species, separated from Oat as having the lower flower of 

 each spikelet male only. At the same time, a minute rudimentary pro- 

 longation of the axis above the upper flower shows its general affinity 

 with the PocBacece, not with the PanicacecB, to which it might be technically 

 referred. 



1. Common False-Oat. Arrhenatherum avenaceum, Beauv. 

 {Holcus, Eng. Bot. t. 813.) 



An erect Grrass 2 or 3 feet ia height, perennial but not forming large 

 tufts. Leaves few and flaccid. Panicle narrow and loose, 6 or 8 inches 

 long, spreading only whilst the flowers are open. Spikelets 3 to 4 lines long, 

 2-flowered, the 2 outer empty glumes thin and pointed, the second nearly as 

 long as the flowers, the outermost rather shorter. The lower flowering 

 glume has a fine bent awn on the middle of the back about twice its own 

 length, and contains stamens only ; the upper flower is perfect, with a mi- 

 nute awn near the top of tlie glume or none at all. 



In meadows, hedges, and thickets, tliroughout Europe and western Asia, J 

 except the extreme north. Common in Britain. Fl. summer. 



XX. HOLCUS. HOLCUS. 

 Panicle somewhat open, but with numerous crowded spikelets, all 2- 



