GRAMINEAE (GRASS FAMILY) 133 



awned lemmas occurs from Me. to Tenn., and especially in the White Mountains ; 

 at higher altitudes this and also the awnless form tend to be more tufted, with 

 numerous short radical leaves. ( Trichodium montanum Torr. ; A. laxiftora, 

 var. montana Tuckerm. ; A. scabra, var. montana Man. ed. 6.) 



4. A. perennans (Walt.) Tuckerm. (THIN GRASS.) Culms erect or some- 

 what decumbent, varying from weak and lax to stout and tall, 3-10 dm. high; 

 leaves numerous, 1-2 dm. long, 1-6 mm. wide ; panicle ovoid-subcylindric, the 

 slender ascending branches dividing and spikelet-b earing from about the middle, 

 the pedicels often divergent; spikelets 2-3 mm. long; lemma 



shorter than the acuminate unequal glumes. (A. intermedia 

 Scribn.) Low open ground or damp shaded places, Me. to 

 Minn., and south w. Sept., Oct. Variable in habit; in deep 

 shade the culms weak and decumbent, the panicles more open 

 with fewer branches, conspicuously divaricate. Flowers later 104 A. perennans. 

 than any other species of Agrostis in the eastern states. FIG. Spikelet x 3. 

 104. Var. EL\TA (Pursh) Hitchc. Differs in having more 

 slender and elongated culms, but particularly in the crowding of the spikelets at 

 the ends of the branches, giving them a more drooping appearance. (A. elata 

 Trin. ; A. altissima Tuckerm. ; Cornucopiae altissima Walt, is doubtful, prob- 

 ably A. alba L.) Swamps near the coast, N. J. to Miss. 



5. A. CANINA L. (BROWN BENT GRASS.) Culms 2-6 dm. high, erect, slen- 

 der ; basal leaves involute-setaceous, those of the culm flat and broader ; panicle 

 at first loose, contracted in fruit; spikelets 2 mm. long ; glumes subequal, acute ; 



awn inserted about the middle, longer than the glumes, bent. 

 Meadows, sparingly naturalized eastw. ; cultivated as a lawn 

 grass under the name RHODE ISLAND BENT. (Nat. from Eurasia.) 

 6. A. borealis Hartm. Culms tufted, 1-4 dm. high ; leaves 

 tufted at base, few on the culm ; panicle open, the lower branches 

 whorled and spreading ; spikelets 2.5-3 mm. long ; awn exserted 

 1-3 mm. beyond the glumes, rarely short or obsolete. {A. rubra 

 autn - not *' 5 A. canina, var. alpina Oakes ; A. novae-angliae 

 Vasey.) Lab. to Alaska and mts. of N. E. and N. Y. ; also 

 Roan ML, N. C. (Eu.) Dwarf forms of high altitudes and latitudes approach 

 dwarf forms of A. hy emails. Some of these have been referred to A. rupestris 

 All., which seems not to occur in N. A. FIG. 105. 



33. POLYP6GON Desf. BEARD GRASS 



Spikelets 1-flowered, in a dense spike-like panicle ; glumes subequal, entire or 

 2-lobed, bearing a straight awn from the apex ; lemma much 

 shorter than the glumes, broad, emarginate or bifid at the 

 apex, awned ; palea smaller than the lemma ; stamens 1-3. 

 Annuals, with flat leaves. (Name composed of TroXtfs, much, 

 and -rruywv, beard.) 



1. P. MONBPELIEN8I9 (L.) Desf. Culms 2-6 dm. high, erect 

 from a decumbent base, usually tufted ; blades linear, scabrous ; 

 panicle 3-10 cm. long, dense, interrupted, pale, and soft silky, 106. P. monsp. 

 often partly included 'in the uppermost sheath ; spikelets 2.5-3 inflorescence x V 5 - 

 mm. long. Waste places, Me., and southw., mostly near the Spikelet, floret,and 

 coast. June-Sept. (Nat. from Eu.) FIG. 106. glumes x 2. 





34. CALAMOVILFA Hack. 





Spikelets 1-flowered, awnless ; callus densely bearded ; glumes rather firm, 

 equal, acute ; lemma 1 -nerved, acute ; palea as long as the lemma, broad, 

 deeply furrowed between the strong nerves. Rather tall rigid perennials, with 

 horizontal rootstocks and loosely spreading panicles. (Name from /cdXa^os, a 

 reed, and Vilfa, a name applied to a genus of grasses by Adanson.) 



1. C. brevipilis (Torr.) Hack. Culms 6-12 din. high, tufted, from a short 

 rizontal rootstock ; the basal sheaths indurated and keeled ; blades long, linear, 



