170 



GRAMINEAE*(GKASS FAMILY^ 



a a. Spikelets appressed to the rhachis. 



7. E. Macounii Vasey. Culms 3-8 dm. high ; sheaths glabrous or the lower 

 sparsely pilose ; blades 8-16 cm. long., 4 mm. wide or less, erect, often involute 



in drying, scabrous, tlie lower usually pilose on 

 the upper surface ; sjjikes narrow, 6-10 cm. long ; 

 spikelets l-'S-Jloicered, the lower solitary and often 

 apparently luith 8 glumes, the missiiig spikeiet 

 being reduced to a single glume; glumes linear- 

 lanceolate, 3-uerved, scabrous, tapering into an 

 awn ; lemmas 8-10 mm. long, scabrous above, 

 with a slender awn 6-10 miu. long. — Prairies, 

 Minn., la., and westw. 



8. E. glaiicus Buckley. Glabrous ; culms 5-10 

 dm. high ; leaves 1.5-2 dm. long, 4-8 mm. xcide, 

 rather thin, flat, scabrous; spikes dender, the 

 internodes 8-10 mm. long ; spikelets -i-G-floioered ; 

 glumes linear-lanceolate, 3-5-nerved, smooth or 



196. E. arenarius x %. 

 Two spikelets. 

 Spikeiet with glumes detached. 



awn twice its own length. 



scabrous on the nerves, short-awned, shorter 

 than the nearly smooth lemma which bears an 

 Moist soil, Out. to Mich., and westw. July, Aug. 



■4- H- Glumes and lemmas not rigid, awnless ; plants reed-like. 



0. E. arenarius L. Culms stout, 6-12 dm, high, from extensively creeping 

 rootstocks ; leaves firm, setaceous-involute toward the ends, the basal ones 

 crowded, 2-3 cm. long, the upper shorter ; spike stiff, dense, 8-25 cm. long, 

 1.5-2 cm. thick; spikelets in pairs or solitary, 3-7-flowered, 2.5-3 cm. long, 

 often glaucous ; glumes and lemmas acuminate or mucronate, short-villous. 

 {E. mollis Trin.) — Maritime sands, Lab. to Me.; and shores of the Great 

 Lakes. (Eurasia.) Fig. 196. 



* * Glumes reduced to short awns. 



10. E. diversiglumis Scribn. & Ball. Culms stout, 9-12 dm. high; leaves lax, 

 1.5-2.5 dm. long, 6-12 mm. wide, scabrous, setaceous-pointed; spike loose 

 below, 1-1.5 dm. long; spikelets 2-flowered ; 

 glumes subulate, scabrous, varying from a mere 

 point to 1.5 cm. long in the same spike; florets 

 8-10 mm. long, hirsute, especially toward the 

 summit, with a divergent awn 2-3 cm. long. — 

 Thickets and open woods, Wis., Minn., and westw. 

 — Approaches Hystrix. 



SitXniox longif6lium J. G. Sm., a western 

 tufted perennial 3-5 dm. high, with crowded basal 

 sheaths, long spreading upper leaves, partially 

 included loose long-awned disarticulating spikes 

 about 1 dm. long, the glumes divided to the base 

 into 2 long divergent awns (6-8 cm. long), occurs 

 in central Kan. and westw. and is reported from 

 central Minn. Fig. 197. 



197. S. longifolium x %. 

 Two spikelets. 

 Spikeiet with glumes detached. 



82. HYSTRIX Moench. Bottle-brush Grass 



Spikelets 2-4-flowered, on very short pedicels, 1-3 together at each joint of 

 the flattened continuous rhachis, facing it as in JElymus, widely divergent at 

 maturity ; glumes reduced to short or minute awns, the first usually obsolete, 

 both often wanting in the upper spikelets ; lemmas convex, rigid, tapering into 

 a long awn ; palea strongly 2-keeled ; grain pubescent at the summit, free within 

 the lemma and palea. — Verennials with simple culms, fiat leaves. and loosely 

 fiowcnul spike.s. (Name from v<TTpi^, a hedgehog, alluding to the bristly spikes.) 



