496 



POACE^. 



its glume, conspicuously 2-keeled. Stamens 3. Styles distinct. 



Grain obovoid-oblong, subterete, with a narrow groove or without 



one. 



A creeping perennial grass^ erect or spreading. Leaf-blades 



jflat. Branches of the panicle sj^reading. capillary. 



There is one species widely dispersed over the temperate parts 



of Europe, Asia, and North America. Nearly related to Colpodium^ 



Panicu la ria, Eragros t is . 



1. C. aquatica (L.) Beauv. 1. c. Avra aquatica L. Sp. PI. 



64 (1753). 



Culms 10-60 cm. high, rather stout. Sheaths 



loose, longer than the internodes; ligule 2-3 mm. 



long; blades 5-15 cm. long, 2-8 mm. wide, obtuse. 



Florets overlapj^ing about half their length, first 



glume 1 mm. long or less, 1-nerved or nerveless, 



second 1-2-3-nerved, about 1.5 mm. long, obovate 



or oval, the ajDcx variously toothed or truncate; 



floral glume about 2.5 mm. long, broadly oval, 



concave, the apex thin and truncate ; palea equal 



to its glume, irregularly truncate. 



Dakota; Montana, Canby <& Scribner 383; 



Europe. 



FIG. lOU. - Cata- H^- (237). Melica L. Sp. PI. 66 (1753). 



brosa aquatica. DaUcum Adans. Fam. 2:323 (1763). Chon- 



A, spikelet ; a, , ^ ' 



florets. (Scrib- ch'achyriwi Nees, Lindl. Introd. Nat. Syst. Ed. 



("'"■•^ 2:449 (1836.) 



Spikelets 2-8- (rarely 1-) flowered, in a narrow or open panicle, 



rachilla continuous and finally articulate above the empty glumes, 



mostly bearing 1 or more rudimentary florets above. Empty 



glumes membranous or hyaline, obtuse or acute, awnless, unequal, 



convex or somewhat compressed on the back, first 3.5- (rarely 1- or 



7-) nerved, second 5-9-nerved, lateral nerves often vanishing within 



the broad margin, often united by cross-veinlets; floral glume thin or 



firm, rounded on the back, 5 to many-nerved, the scarious tip blunt 



or acute, ending in 2 teeth, central nerves sometimes slightly excur- 



rent, as in Bromus; palea 2-nerved, often emarginate or 2-toothed, 



