GRAMINEAE (GRASS FAMILY) 



133 



104. A. perennans, 

 Spikelet X 8. 



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 

 namerous short radical leaves. ( Trichodiiim montanum Torr. ; A. laxiflora, 

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



4. A. per§nnans (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 spilcelet-bearing from about the middle, 

 the pedicels often divergent; spikelets 5-3 mm. long; lemma 



shorter than the acuminate unequal glnmes. {A. intermedia jjliS 



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



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



shade the culms weak and decumbent, the panicles more open ' 



with fewer branches, conspicuously divaricate. Flowers later 

 than any other species of Agrostis in the eastern states. Fig. 

 104. Var. elXta (Pursli) 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 

 auth., not L. ; A. canina, var. alpina Oakes ; A. novae-angliae 

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

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

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

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



105. A. borealis. 

 Spikelet X sy^. 



33. P0LYP6G0N Desf. Beard Grass 



Spikelets l-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 iroXiis, much, 

 and Tvijiyiiv, beard.) 



1. P. MONSPELiENSis (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 silkxj, 

 often partly included in the uppermost sheath ; spikelets 2.5^ 

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

 coast. June-Sept. (Nat. from Eu.) Fig. 106. 



106. P. monsp. 



Inflorescence x Vc> 



Spikelet, floret,and 



glumes X 2. 



34. CALAMOViLFA Hack. 



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

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

 deeply furrowed between the strong nerves. — Rather tal! rigid perennials, with 

 horizontal rootstocks and loosely spreading panicles. (Name from /niXa/ios, a 

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



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

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



