170 



GRAMINEAE (GRASS FAMILY) 



196. E. arenarius x 

 Two spikelets. 

 Spikelet with glumes detached. 



a a. Spikelets oppressed 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, the lower usually pilose on 

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

 spikelets 1-3-Jlowered, the lower solitary and often 

 apparently with 3 glumes, the missing spikelet 

 being reduced to a single glume; glumes linear- 

 lanceolate, 3-nerved, scabrous, tapering into an 

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

 with a slender awn 6-10 mm. long. Prairies, 

 Minn., la., and westw. 



8. E. glaucus Buckley. Glabrous ; culms 6-10 

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

 rather thin, flat, scabrous ; spikes slender, the 

 internodes 8-10 mm. long ; spikelets 3-6-flowered ; 

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

 scabrous on the nerves, short-owned, shorter 

 than the nearly smooth lemma which bears an 

 awn twice its own length. Moist soil, Ont. to Mich., and westw. July, Aug. 



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



9. 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 aions. 



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 j 



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. 



SIT\NION LONGIFOLIUM 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. 

 Spikelet 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 Elymus, 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. 1'erennials with simple culms, flat leaves and loosely 

 flowered spikes. (Name from vvrp^, ^.hedgehog, alluding to the bristly spikes.) 



