Usually tall grasses, with flat leaf-blades and terminal spikes. Spikelets 2-several-flowered, in pairs, rarely in 3's, at each node of the rachis. Empty scales wanting, or sometimes appearing as mere rudiments; flowering scales narrow, convolute, rigid, rounded on the back, 5-nerved above, terminating in an awn; palet scarcely shorter than the scale, 2-keeled. Stamens 3. Styles very short, distinct. Stigmas plumose. Grain oblong, adhering to the palet when dry. [Greek name of the Porcupine, referring to the long awns.]

Four species, the following and a Californian one in North America. Type species: Elymus Hystrix L.

1. Hystrix Hystrix (L.) Millsp. Bottle-Brush Grass

Fig. 717

Elymus Hystrix L. Sp. PI. Ed. 2, 124. 1762. Asprella Hystrix Willd. Enum. 132. 1809. Gymnostichum Hystrix Schreb. Beschr. Gras. 2: 127.

pi. 47. 1810. Hystrix Hystrix Millsp. Fl. W. Va. 474. 1892.

Culms 2°-4° tall, erect, simple, smooth and glabrous. Sheaths usually shorter than the in-ternodes; ligule very short; blades 4 1/2'-9" long, 3"-6" wide, smooth beneath, . rough above; spike 3'-7' in length; spikelets at length widely spreading, 4"-6" long, exclusive of the awns; empty scales awn-like, usually present in the lowest spikelet; flowering scales 4"-6" long, acuminate into an awn about 1' in length.

In rocky woods. New Brunswick to Ontario, south to Georgia, Illinois and Nebraska. Spikelets easily detached, even when young. Bottle-rush. June-July.