126 POACEAE 



and flexuous : scales of the spikelet rough, strongly hispid on the keel, the flowering one 



usually exceeded by the second and bearing a rough awn 1-2 mm. long from the 2-toothed 



apex. [C arundinacea YViV. jyendula A. Gray.] 



In damp woods, Newfoundland to New .Tersey and British Columbia, and in the Alleghanies to 

 North Carolina, and in the Rockies to Colorado and Ctah. Also in northern Europe. Summer and fall. 



63. AGROSTIS L. 



Annual or perennial usually tufted grasses, with flat or setaceous leaf-blades and ter- 

 minal often slender contracted or open panicles with numerous branches. Spikelets very 

 numerous, small, 1-flowered, the rachilla articulated above the empty scales. Scales 3, the 

 2 outer empty, persistent, membranous, keeled, acute, awnless, the third one shorter, 

 thin-hyaline, aw-nless, or sometimes bearing a slender dorsal often geniculate awn, enclos- 

 ing a perfect flower and frequently also a short very thin liyaline palet rarely more than 

 i as long as the scale, sometimes minute or wanting. Stamens usually 3. Styles distinct, 

 very short. Stigmas plumo.se. Bent Grass. 



Palet of the spikelet conspicuous, at least % as long as the scale. 



Panicle open, its branches long and at' least some of them naked below: 



spikelets hispidulous on the keel only. 1. ,4. alba. 



Panicle dense and contracted, its branches" short and ascending or erect, spike- 

 let-bearing to the very base : spikelets strongly hispidulous all over. 2. A. vcrttdlluta. 

 Palet inconspicuous, minute, or wanting. 



Flowering scale awnless, or very rarely bearing a short awn. 



Stems weak, usually decumbent and often prostrate at the base : leaf-blades 



lax : panicle oblong, the spikelets 1.5-2 mm. long. 3. A. perennann. 



Stems, and usually also the leaf-blades, erect. 



Branches of the panicle capillary, elongated, commonly dividing above 

 the middle. 

 Spikelets 1.5-2 mm. long: leaf-blades short. 4. A. Iiyemalis. 



Spikelets 2.5-3 mm. long : leaf-blades elongated. . 5. .4. aitissima. 



Branches of the panicle not elongated, dividing at or below the middle. 



Spikelets about 2 mm. long : a grass of low elevations. 6. ^4. Scribneriana. 



Spikelets 2. .5-3 mm. long : a high mountain grass. 7. A. Novae- Angliae. 



Flowering scale awned. 



Awn glabrous, rigid, usually bent, less than twice as long as the spikelet. 



Branches of the panicle generally ascending : spikelets 2 mm. long. 8. A. canina. 



Branches of the panicle usually spreading : spikelets 2.5-3 mm. long. 9. A. rubra. 



Awn very finely filiform, barbellate, at least twice as long as the spikelet. 10. .4. Elliottiana. 



1. Agrostis dlba L. Stems 2-8 dm. tall, erect, or decumbent at the base, often 

 stoloniferous : leaf-blades 5-20 cm. long, 2-6 mm. wide, rough or smooth : panicle 5-23 

 cm. long, usually open, or sometimes contracted after flowering, green or purplish : spike- 

 lets 2-2.5 mm. long, the empty scales about equal, acute, hispidulous on the keel. 



In fields and meadows, nearly throughout North America. Summer. Red-top. 



2. Agrostis verticillata Vill. Stems tufted, 8 dm. tall or less : leaf-blades erect, 

 linear to lanceolate, 1.5 dm. long or less, flat, very rough, 2-8 mm. wide : panicle 4-12 

 cm. long, dense, often interruj)ted, its short branches a.-^cending or erect, densely spikelet- 

 liearing to the base : spikelets 1.5-2 mm. long, the empty scales strongly hispidulous. 



In moist places, Texas to Arizona. Also in Mexico. Spring to fall. 



3. Agrostis per6nnans ( Walt. ) Tuckerm. Stems 3 8 dm. long from a decumbent 

 or prostrate base, weak, slender, simple, or sparingly branched above : leaf-blades 5-15 

 cm. long, 2-4 mm. wide, lax, rough : panicle 1-2 dm. long, open, oblong, its branches 

 widely s})reading, the branchlets and pedicels divergent : spikelets 1.5-2 mm. long, the 

 empty scales hispidulous on the keel. 



In woods, New Hampshire and Massachusetts to Ohio, Kentucky and North Carolina. Summer 

 and fall. 



4. Agrostis hyemalis (Walt.) B.S.P. Stems 3-6 dm. tall, slender: leaf-blades 

 5-13 cm. long, 1-3 mm. wide, usually erect, roughish : panicle 1.5-6 dm. long, usually 

 purplish, the very rough capillary branches ascending or spreading, often drooping, the 

 lower ones 7-15 cm. long : spikelets 1.5-2 mm. long. [J., scabra Willd.] 



In dry or moist soil, throughout nearly the whole of North America. Summer. 



5. Agrostis altissima (Walt.) Tuckerm. Stems 6-12 dm. tall, erect: leaf-blades 

 elongated, 1.5-3 dm. long, 2-3 mm. wide, rough : panicle 2-2.5 dm. long, its branches 

 ascending or erect, the lower 5-10 cm. long, spikelet-bearing at the end : sjiikelets 2.5-3 

 mm. long, occasionally bearing a short awn. [.4. elata Trin. ] 



In sandy swamps. New Jersey to Florida and Alabama. Summer and fall. 



6. Agrostis Scribneriana Nash. Stems 3-9 dm. tall, erect, tufted, rather slender : 

 leaf-blades 1-2.5 dm. long, 2-6 mm. wide, rough : panicle 1-2.5 dm. long, its ascending 

 branches 3.5-8 cm. long : spikelets about 2 mm. long, on appressed pedicels. [AfjroMis 

 inti'niiedia Scribn., not Balb. ] 



In dry soil, Massachusetts to New York, Tennessee and Missouri. Summer and fall. 



