168 



GEAMINBAE (GRASS FAMILY;) 



wide ; lateral pair of spikelets each reduced to 1-3 spreading awns ; glumes ct 

 perfect spikelets awn-like, 3-6 cm. long, spreading ; lemma 6-8 mm. long, with 

 an awn as long as the glumes ; all the awns very slender, 

 scabrous. — Coast, Lab. to N. J. ; prairies and waste ground, 

 Ont. to 111., Kan., and westw. June-Aug. — Of ten a trouble- 

 some weed. (Eurasia.) Fig. 190. 



2. H. pusillum Nutt. Annual, 1-4 dm. high ; leaves 6 cm. 

 or less long, erect, scabrous ; spikes erect, 2-7 cm. long, 

 1-1.6 cm. wide; lateral pair of spikelets 

 abortive ; first glume of each, and both 

 glumes of fertile spikelet, dilated above the 

 base, attenuate into a slender awn 8-15 mm. 

 long, equaling the awned lemma. — Plains, 

 especially in saline soil, 0. to Mo., and 

 westw. ; sparingly introduced, D. C, Va., 

 and southw. along the coast. May, June. 

 Fig. 191. 



3. H. nodftsum L. Similar to the pre- 

 ceding, usually taller ; spike 2-8 cm. long, 



191. II. pusillum. about 1.5 cm. wide ; all the glumes awn- 



Three spikelets X 3. nj^g^ 1-1 . 5 mm. long. — Thin dry soils, Ind. , 



Minn., and northw., s. to Tenn. and Tex. (Eurasia.) Fig. 



■'^^; „ , , . 192. H. nodosum. 



4. H. Pammeli Sonbn. & Ball. Perennial, er&ct or gem- xhi-ee spikelets x 8. 

 culate at base, 6-10 dm. high ; leaves 1.2-2 dm. long, 5-8 mm. 

 wide, long-acuminate, scabrous ; spikes nodding, 8-17 cm. long, 2-3 cm. wide ; 

 the lateral pair of spikelets nearly sessile, perfect ; the middle spikelet 2-Jlowered 

 or often with the rudiment of a third floret; glumes 2.3-3.5 cm. long, subulate- 

 attenuate into slender awns. — Prairies, 111., la., S. Dak., and Wyo. June- 

 Aug. — Intermediate between Sordeum and Elymus; closely related to culti- 

 vated barley. 



81. ELYMUS L. Wild Rye, Lyme Grass 



Spikelets 2-6-flowered (uppermost florets imperfect), in pairs (sometimes soli- 

 tary below, rarely in 3's or 4's), sessile at the alternate notches of ihe continuous 

 rhachis ; rhachilla articulated above the glumes and between the norets ; glumes 

 equal, rigid, narrow, 1-8-nerved, acute or awn-pointed, placed edge to edge in 

 front or toward the sides of the florets (which are dorso-ventral to the rhachis of 

 the spike) simulating an involucre at each joint of the rhachis ; lemmas convex, 

 obscurely 5-nerved, obtuse, acute or awned from the apex ; paleas a little 

 shorter than their lemmas ; grain hairy at the summit, adherent to the lemma 

 and palea. — Erect tufted perennials with flat leaves and closely flowered 

 terminal spikes. (Name from ^Xiieix, to roll up, an ancient one for soma 

 grain.) 



Glumes as long as the florets or nearly so. 

 Lemmas awned. 

 Spikelets spreadinf?. 



Glumes awl-shaped . * 6. ^. striatus. 



Glumes narrowly lanceolate. 

 Glumes indurated below ; spike erect. 



Awn lonf;^ and spreading % E. australis. 



Awn short and erect 1. ^, virginicits. 



Glumes not indurated below ; spike noddii T. 

 Spike large and densely flowered throughout . . . . i. E. robusius. 

 Spike more slender and less densely flowered, interrupted 

 below. 



Lemma hirsute S. E. canadensis. 



Lemma minutely scabrous 5. E. brachystaehys 



Spikelets appressed to rhachis. 



Spikelets in pairs . . ■ 8. E. glaucus. 



Spikelets mostly solitary 1. E. Maeounii. 



Lemmas awnless • . , . 9. ff. arennrius. 



^If^nies reduced to short awns 10. £*. diversiglumis. 



