MANUAL OF THE GRASSES OF THE UNITED STATES 259 



Terrell grass. A variable species of which the following intergrading 

 varieties may be distinguished. 



Elymus virginicus var. glabriflorus (Vasey) Bush. Glumes 

 mostlv less bowed out; lemmas glabrous; awns mostly 2 to 3 cm long, 

 the spike more bristly. 01 — Maine to Kansas, south to Florida 

 and New Mexico. 



Elymus virginicus var. halophilus (Bickn.) Wiegand. More 

 slender, usually glaucous; blades narrower, often becoming involute; 

 spikes and spikelets somewhat smaller. % — Brackish marshes 

 and moist sand along the coast, Maine to New Jersey. 



Elymus virginicus var. submuticus Hook. Glumes and lemmas 

 awnless or nearly so. % — Woods and open ground, Quebec to 

 Washington, south to Rhode Island; Ohio and Kentucky to Okla- 

 homa and Montana. 



Elymus virginicus var. intermedius (Vasey) Bush. Glumes, 

 lemmas, and rachis more or less hirsute, the awns about as in E. 

 virginicus. % (E. hirsutiglumis Scribn.) — Thickets and low ground, 

 Maine to Iowa, south to Florida and Texas. 



Elymus virginicus var. australis (Scribn. and Ball) Hitchc. 

 Differing from E. virginicus var. intermedius in the stouter, bristly 

 spike and longer awns ; differing from E. virgin- 

 icus var. glabriflorus in the hirsute or strongly 

 scabrous glumes and lemmas. % — Prairies, 

 rocky hills, and open woods, Vermont to Iowa, 

 south to Florida and Texas. 



Elymus gig ante us Vahl. Robust perennial from 

 stout rhizomes; blades numerous at base, elongate; spike , IQUBK m _ m 

 dense, 15 to 20 cm long, about 2 cm thick; glumes Etgmtu argtnkms. 



and lemmas sharp-pointed, the glumes glabrous, the 

 lemmas pubescent below. 21 — Occasionally cultivated for ornament. Siberia 



44. SITAXION Raf. Squirreltail 



Spikelets 2- to few-flowered, the uppermost floret reduced, usually 

 2 at each node of a disarticulating rachis, the rachis breaking at the 

 base of each joint, remaining attached as a pointed stipe to the 

 spikelets above; glumes narrow or setaceous, 1- to 3-nerved, the 

 nerves prominent, extending into one to several awns, these (when 

 more than one) irregular in size, sometimes mere lateral appendages 

 of the long central awn, sometimes equal, the glume being bifid; 

 lemmas firm, convex on the back, nearly terete, 5-nerved, the nerves 

 obscure, the apex slightly 2-toothed, the central nerve extending into 

 a long, slender, finally spreading awn, sometimes one or more of the 

 lateral nerves also extending into short awns; palea firm, nearly as 

 long as the body of the lemma, the two keels serrulate. Low or rather 

 tall tufted perennials, with bristly spikes. Type species, Sitanion 

 elymoides Raf. (S. hystrix). Name from Greek sitos, grain. 



The species are exceedingly variable, being glabrous to densely 

 pubescent and green to glaucous; the glumes and lemmas vary in 

 division and length of awns. Some 15 to 25 variations have been 

 recognized as species, but study of extensive collections shows that 

 most of the characters used in differentiating the forms are incon- 

 stant and combine in various ways. 



