POACEAE. 25 



cm. long: spikelets 6-8 mm. long, the empty scales unequal, acute, the flowering 

 scale appressed-pubeseent below, much longer than the second one and much 

 exceeded by the long-acuminate palet. M. Bare, in dry soil. Limestones. 



2. S. asper (Michx.) Kunth. Stems 4-12 dm. tall: leaf -blades 5 dm. long or 

 less, 2-5 mm. wide: panicle 2-3 dm. long, usually more or less included in the 

 upper leaf -sheath: spikelets 5-6 mm. long, the scales obtuse, the first about 

 as long as the second, the flowering scale glabrous, considerably exceeding the 

 second one, about equalling the palet or a little shorter or longer than it. M. 

 Rare, in sandy soil. Limestones. 



3. S. heterolepis A. Gray. Stems 3-10 dm. tall: leaf -blades involute-setaceous: 

 panicle 7-25 cm. long: spikelets 4-5.5 mm. long, the empty scales unequal, 

 acuminate, the lower subulate, about i as long as the broad second one, some- 

 times awn-pointed, the flowering scale obtuse or acute. S. Very rare, on 

 dry banks. Schists. 



24. CINNA L. Tall perennial grasses, with flat leaf -blades and long 

 terminal contracted or open panicles, often nodding, its branches slender and 

 usually drooping. Spikelets numerous, flattened, 1 -flowered, the rachilla articu- 

 lated below the empty scales. Scales 3, the 2 outer empty, persistent, keeled, 

 acute, the third one similar in texture, stalked, bearing just below the some- 

 what obtuse apex a short awn or awn-like point, the scale enclosing a slightly 

 smaller 1-nerved keeled palet, the keel minutely ciliate, and a perfect flower. 

 Stamen 1. Styles short, distinct. Stigmas plumose. 



1. C. arundinacea L. Stems 6-15 dm. tall: leaf -blades 1.5-3 dm. long, 4-14 

 mm. wide: panicle 1.5-3 dm. long: scales of the spikelet acute, rough, the 

 flowering scale slightly exceeded or equalled by the second, usually bearing an 

 awn about 0.5 mm. long from the 2-toothed apex. Rather common, in moist 

 woods and along streams. Sum. and fall. WOOD REED-GRASS. 



25. CALAMAGROSTIS Adans. Erect usually perennial grasses, with gen- 

 erally 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 throughout, 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 3i. Styles short, distinct. Stigmas plumose. REED BENT- 

 GRASS. 



Rachilla with its prolongation hairy the whole length. 1. C. canadensis. 



Rachilla with its prolongation hairy only at the top. 2. C. cinnoides. 



1. C. canadensis (Michx.) Beauv. Sterna 6-15 dm. tall: leaf -blades 1-3 dm. 

 long or more, 2-8 mm. wide: panicle 1-2 dm. long, open, usually purplish, 

 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. N. S. Fre- 

 quent, in swamps. Sandstones and schales, schists. Sum. BLUE-JOINT 

 GRASS. 



2. C. cinnoides (Muhl.) Scribn. Stems 9-15 dm. tall: leaf -blades 1-3 dm. long 

 or more, 4-10 mm. wide: panicle 7-18 cm. long, contracted: spikelets 6-8 mm. 



