166 



GRAMINEAE (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 ayp6s, 

 afield, and irvpbs, 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 faintly nerved, long-acuminate 1. 



Glumes strongly nerved, abruptly narrowed to a rather blunt point 2. 

 Culms tufted ; no creeping rootstocks. 

 Awn not longer than the lemma. 



Glumes thin, widened above the middle 5. A. Inflorum. 



Glumes firm, narrowed from below the middle 6. A. trm-nnn. 



Awn about twice the length of the lemma. 



Spike nodding, symmetrical 7. A. can in urn. 



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



4. A. 



3. A. repens. 



A. Suntlnl. 

 A. pungens. 



1. A. Smithii Rydb. (BLUE-JOINT.) 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, | or f as long as spikelet, 

 nerves usually faint ; lemmas mucronate or awn-pointed, Ji</r<L 

 faintly nerved. (A. occidentale Scribn. ; 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. PITNGENS (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 xt'tlc 

 of the rhachis, overlapping, usually alternately diverging to the 

 right and left, thus appearing ^-ranked, 7-11-floweced, 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, 

 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 ^-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 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 ami oftm involute ; the 5-9-flowered usually subterete spikelets <1< n*<hj 

 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. 



". A. biflbrum (Brignoli) R. & S. Culms usually decumbent at base, 3-C dm. 



186. A. Sinithii. 

 Spikelet x 3. 



1S6. A. 

 Spikelets x %. 

 Floret x 1%. 



