80 Bl'Li.eti.n VII. 1. 



worth much more than generally estimated. Being tall, it will 

 yield much hay per acre. July — August. 



2. Calamagrostis Nuttalliana Steud. Reed Bent-grass. 

 Plate XXVII. Figure 105. 



A stout, reed like grass, three to five feet high, with a narrow, 

 almost spike-like panicle. Leaves elongated (a foot or more), 

 scabrous, the upper face more or less hairy; ligule two to three 

 lines long. Panicle contracted, four to eight inches long, very 

 densely-flowered. Empty glumes three to four lines long, long 

 acuminate-pointed, strongly scabrous on the keel, the second dis- 

 tinctly three-nerved. Flowering glume a little shorter than the 

 empty ones, rigid, excepting at the hyaline tip, minutely scabrous 

 all over, copiously hairy at the base, hairs shorter than the glume, 

 exceeded by the tuft at the apex of the otherwise smooth prolonga- 

 tion of the rachilla. Awn from above the middle, rather stout, a 

 little exceeding the glume. Palea distinctly two-nerved, acute, 

 nearly as long as the glume. Grain wholly free, sparsely hairy all 

 over, with a dense tuft of short hairs at the apex. 



Moist grounds, July — August. Our specimens are from Middle 

 Tennessee (Cowan) and the mountains of East Tennessee. The 

 jspecies ranges northward to New England. 



Tribe IX. AVEXE^. 



Spikelets, two- to several-flowered, outer empty glumes usually 

 longer than the first floral glume; one or more of the floral glumes 

 awned on the back or from between the teeth of the bifid apex 

 (some cultivated forms excepted): awn usually twisted or genic- 

 ulate. Rachilla, at least at the base of the flowering glume, 

 usually hairy. 



A tribe comprising twenty-three genera, and over 300 species, 

 widely distributed in the temperate regions of both the Old and 

 New World; particularly abundant in South Africa and Australia, 

 a few extending beyond the arctic circle. Several of the species 

 are valued as forage plants. Cultivated Oats, Avena sativa, is the 

 best known example of this tribe. 



28. HOLCUS Linn. Sp. PI. 1047 (1753)- 



Spikelets two-fiowered, crowded in open panicles, the lower flower 

 raised above the outer glumes upon a curved internode of the 

 rachilla, hermaphrodite, awnless, the upper flower staminate 

 (rarely hermaphrodite\ its glume bearing a short curved awn 

 near the apex; rachilla smooth, articulated below the empty 

 glumes and also below the floral glumes. Empty glumes nearly 

 equal, compressed, boat-shaped, longer than the florets. Lodicules 

 (in H. Ii7iatus) lanceolate, acute. Stamens three. 



Annuals or perennials, with usually flat leaves and densely-flow- 

 ered terminal panicles. 



