166 



GRAMINEAB (GRASS FAMILY) 



of the spikelet, usually subcoriaceous and rigid, several-nerved, usually shorter 

 than the florets, acute or awned ; lemmas convex or slightly keeled above, 5-7- 

 nerved, acute or awned from the apex ; palea shorter than its lemma, bristly- 

 ciliate on the keels ; grain pubescent at the summit, usually adherent to the 

 palea. —Perennials with simple culms and terminal spikes. (Name from d-/p6s, 

 a field, and irupSs, wheat. ) 



J. A. repens. 



1. A. Smithii. 



2. A. pungens. 



A. Mflorum. 

 A. tenerum. 



Culms solitary or lew, erect from creeping rootstocks. .y.tachvum. 



Lemmas densely pubescent ....-..'•• 4- -*• dasystactiyuTn. 



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, widened above the middle »• 



Glumes firm, narrowed from below the middle »>• 



Awn about twice the length of the lemma. rnr,4vnm 



Spike nodding, symmetrical .-..-...' ^. -j' ^^JtV^l-.. 

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



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

 hi^h ; 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, | or f as long as spikelet, 

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

 faintly nerved. {A. occidentale' Scr'ihn. ; A. 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. PUNGENS (Pers.) R. & S. Glaucous; culms slender, 

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

 rigid involute point; spikes 1-1.2 dm. long, flattened parallel 

 to the rhachis ; the broad compressed spikelets along each side 

 of the rhachis, overlapjying, usually alternately diverging to the 

 right and left, thus appearing 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. REPENS (L.) Beauv. (Couch, Quitch, 

 or Quick Grass.) Bright green or glaucous, 

 8-12 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 much as 5 ram. long.— 

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

 incr rootstock and the lower portion of the culm are colored bright greenisn 

 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 often 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 north w. Aug. o a a 



5. A. biflbrum (Brignoli) R. & S. Culms usually decumbent at base, 6-b am. 



185. A. Smithii 

 Spikelet x 1 



186. A. repens. 

 Spikelets x %. 

 Floret X lYz. 



