POACEAE 127 



7. Agrostis Novae Angliae Tuckerm. Stems 2-4 dm. tall, erect, tufted : leaf-blades 

 2.5-9 cm. long, 2 mm. wide or less, erect, generally involute, rough : panicle 1-2 dm. long, 

 open, the branches spreading or ascending : spikelets 2.5-3 mm. long, very hispidulous on 

 the keel. 



In dry soil, Newfoundland and on the high mountains of New England, New York and North 

 Carolina. Summer. 



8. Agrostis canina L. Steins 3-6 dm. tall, erect, slender : leaf -blades 2.5-8 cm. 

 long, 2 mm. wide or less, rough : panicle 5-18 cm. long, contracted in fruit, its branches 

 slender, naked below, ascending or spreading in flower : spikelets 2 mm. long, on ap- 

 pressed pedicels, the flowering scale with an awn 2-4 mm. long inserted just above the 

 middle. 



In meadows, Newfoundland and Alaska to Pennsylvania and Tennessee. Naturalized from 

 Europe in the South. Summer and fall. 



9. Agrostis rubra L. Stems 1.5-6 dm. tall, erect : leaf -blades 5-10 cm. long, 1-3 

 mm. wide : panicle 6-13 cm. long, open, the branches usually widely spreading and more 

 or less flexuous, rarely erect : spikelets 2.5-3 mm. long, the flowering scale bearing a gen- 

 erally bent awn 4-5 mm. long and inserted below the middle. 



In dry or wet soil, summits of the highest mountains in New England, New York and North 

 Carolina. Summer. 



10. Agrostis Elliottiana Schult. Stems 1-4 dm. tall, erect, slender, tufted : leaf- 

 blades 1-5 cm. long, 2 mm. wide or lass, rough : panicle 5-13 cm. long, usually narrow, 

 sometimes open, the branches slender, naked below, erect or ascending : spikelets 1.5 mm. 

 long, the third scale bearing a very finely filiform flexuous barbellate awn 2-4 times its 

 length, inserted just below the apex. [Agrostis arachnoides Ell.] 



In dry soil, South Carolina to Kentucky, Florida and Texas. Spring and summer. 



64. GASTRIDIUM Beauv. 



Tufted annual grasses, with flat leaf-blades and spike-like dense cylindric shining 

 panicles. Spikelets numerous, crowded, 1 -flowered, the rachilla articulated above the 

 empty scales and extending beyond the flower. Scales 3, the 2 outer empty, unequal, per- 

 sistent, narrow, keeled above, acute, sometimes short-awned, the third scale much shorter, 

 thinly hyaline, broad, denticulate at the truncate apex, awnless, or sometimes bearing an 

 awn below the apex, enclosing a narrow somewhat shorter palet and a perfect flower. 

 Stamens 3. Styles short, distinct. Stigmas plumose. 



1. Gastridium lendlgerum (L. ) Gaud. Stems 1.5-5 dm. tall, erect, or decumbent 

 at the base, often branched : leaf-blades erect, 1 dm. long or less, 2-4 mm. wide : panicle 

 3-13 cm. long, dense, 5-13 mm. in diameter : spikelets, exclusive of the awn, 3-4 mm. long. 



In dry places, Texas. Also in Oregon and California. Naturalized from Europe. Summer. 



65. CALAMAGROSTIS Adans. 



Erect usually perennial grasses, with generally flat, sometimes involute leaf -blades, and 

 terminal contracted or open panicles. Spikelets numerous, 1-flowered, commonly small, 

 the rachilla usually prolonged beyond the flower, the prolongation either pilose through- 

 out, the usual state, or with a terminal tuft of long hairs. Scales 3, the 2 outer empty, 

 persistent, narrow, keeled, acute or acuminate, the third scale much shorter than the others, 

 very thickly hyaline, with a basal ring of hairs which are from one-half as long as the scale 

 to somewhat exceeding it, rarely very short or almost wanting, bearing a usually delicate 

 dorsal awn which is rarely twisted at the base, and enclosing a small narrow thinly hyaline 

 palet and a perfect flower. Stamens 3. Styles short, distinct. Stigmas plumose. 



Prolongation of the rachilla of the spikelet hairy throughout : spikelets 3-4 mm. long. 1. C. Canadensis. 

 Prolongation of the rachilla of the spikelet hairy at the summit : spikelets &-8 mm. long. 2. C. cinnaides. 



1. Calamagrostis Canadensis (Michx.) Beauv. Stems 6-15 dm. tall, smooth or 

 somewhat rough : leaf-blades 1-3 dm. long or more, 2-8 mm. wide, rough : panicle 1-2 

 dm. long, open, usually purplish, its branches spreading or ascending, naked at the base : 

 spikelets 3-3.5 mm. long ; flowering scale with a delicate awn, the basal hairs equalling or 

 a little shorter than the scale. 



In swamps and wet soil, Prince Edward Island to British Columbia, New Jersey, Ohio, Iowa, Utah 

 and Oregon. Represented in our area, on the high mountains of North Carolina, by C. Canadensis 

 acumindta Vasey, which differs in having the panicle usually smaller, denser and darker purple, and 

 in the larger spikelets which are 3.5-4 mm. long and with the scales more pointed. Summer. 



