166 



GRAMIXEAE (GRASS FAMILY) 



4. 



1. 



2. 



5. 



6. 



A. dasystachyum. 



A. repens. 



A. Smithii. 

 A. pungens. 



A. Mflorum. 

 A. tenerum. 



A. caninum. 



A. Richardaonii, 



of tbe spikelet, usually subcoriaceous and rigid, several-nerved, usually shortei 

 than the florets, acute or awned ; lemmas convex or slightly keeled above, ;V7- 

 nerved, acute or awned from the apex ; palea sliorter than its lemma, bristly. 

 cili:ite on tlie keels ; grain pubescent at the summit, usually adherent to the 

 palea. — Perennials with simple culms and terminal spikes. (Name from d7p6s, 

 a fields and 7ru/36s, wheat.) 



Culms solitary or few, erect from creeping rootstocks. 



lemmas densely pubescent • . . 



Lemmas glabrous or scabrous. 

 Leaves flat, thin, with fine scarcely prominent nerves .... 

 Leaves becoming involute, thick, with prominent thick nerves. 



Glumes faintlv nerved, long-acuminate 



Glumes strongly nerved, abruptly narrowed to a rather blunt point 

 Culms tufted ; no creeping rootstocks. 

 Awn not longer than the lemma. 



Glumes thin, wdened above the middle 



Glumes firm, narrowed from below the middle 



Awn about twice the length of the lemma. 



Spike nodding, symmetrical 1. 



Spike erect, one-sided .... 8. 



1. A. Smithii Rydb. (Blue-joikt.) Glaucous ; culms rigid, 3-15 dm. 

 high; leaves rigid, bluish green, scabrous, becoming involute, 1-2 dm. long, 

 4-6 mm. wide, basal leaves longer; spikes 0.8-1.5 dm. long; 

 spikelets 7-13-flowered, 1.2-2 cm. long, usually somewhat dis-- 

 tant, glabrous or nearly so, acute, compressed, divergent, some- 

 times in pairs ; glumes acuminate, i or f as long as spikelet, 

 nerves usually faint ; lemmas mucronate or awn-pointed, hard, 

 faintly nerved. {A. occidentals Scribn. ; .4. spicatum Scribn. & 

 J. G. Sm., as to description, not Festuca spicata Pursh.) — 

 Prairies, Mich, to Kan., and westw. July. — Rootstock and 

 lower portion of culms gray or tawny, not bright yellow-green 

 as in A. repens. Fig. 185. 



2. A. puxGENS (Pers.) R. & vS. Glaucous; culms slender, 

 riuid, 6-9 dm. high ; leaves 18-24 cm. long, narrowed into a 

 rig.'d involute point; spikes 1-1.2 dm. long, flattened parallel 

 to t!ie rhachis ; the broad compressed spikelets along each side 

 of the rhachis, overlapping, usually alternately diverging to the 

 right and left, thus apjpearing 4-ranked, 7-11-flowered, 1.5-2 

 cm. long ; glumes abruptly narrowed to a 

 blunt point. 8-9 mm. long ; lemmas about 1 cm. 

 long, acute, mucronate or very short-awned. 

 (A. tetrastachys Scribn. & J. G. Sm.) — Sandy 

 seacoast of Me. July. (Nat. from Eu.) 



3. A. RKPENs(L.)Beauv. (Couch, Quitch, 

 or Quick Gkass.) Bright green or glaucous, 

 3-12 dm. high ; sheaths glabrous or the lower 

 sparsely pilose ; blades flat or inrolled, sca- 

 brous or sparsely pilose above ; spikes 0.5-1.5 dm. long, slender 

 or stout; spikelets about b-flowered, 1-1.5 cm. long; glumes 

 8-10 mm. long, acuminate or awn-pointed, strongly nerved ; 

 lemmas about 1 cm. long, glabrous or more or less scabrous, 

 strongly nerved, pointed or terminating in an awn as nuich as 5 mm. long. — 

 Fields, roadsides and waste places, common. — The internodes of the long creep- 

 ing rootstock and the lower portion of the culm are colored bright greenish 

 yellow ; scales of the rootstock distant and often conspicuous. (Nat. from 

 Eu.) Fig. 186. 



4. A. dasystachyum (Hook.) Scribn. Resembling the last, glaucous ; leaves 

 narrow and oftf^n involute ; the 5-9-flowered usually subterete spikelets densely 

 downy-hairy all over except the strongly nerved glumes ; lemmas thinner with 

 scarious margins, mostly long-acuminate. — Sandy shores of Lakes Huron and 

 Michigan, and northw. Aug. 



5. A. biflorum (Brignoli) R. & S. Culms usually decumbent at base, 3-6 dm. 



185. A. -Smithii. 

 Spikelet x3. 



186. A. repens. 

 Spikelets x %. 

 Floret X iVg- 



