146. Gramineae 339 



38. Agrostis L. — Ik-nt Grass 



1. Lenuna awnless. 



2. Palet half the length of the Icinnia or longer; spikelets 2-2.3 nun 

 long. 

 3. Panicles open, llie branches ascending; stems erect or some- 

 what decumbent at base, with strong horizontal rhizomes 

 but no conspicuous stolons; leaves 4-10 mm wide; road- 

 sides, fields, lawns, very common; nat. from Eur. June- 

 Aug. Redtop A. alba L. 



3. Panicles contracted, the branches appressed; stems strongly 



decinnbent. rooting at the nodes and developing long 

 stolons: leaves mostly 2-5 mm wide; roadsides, fields, cult, 

 ground, occasional; nat. from Eur. June-Aug. Creeping 



Bent Grass A. palustris Huds. 



2. Palet lacking or minute. 



4. Panicle very difluse. 15-60 cm long, often piu-plish at matiu'- 



ity, the capillary branches scabrous, 5-15 cm long, spikelet- 



bearing only near the tips. 



5. Spikelets 1.5-2 mm long; anthers 0.2 mm long; glumes 



spreading in fruit and exposing the grain; roadsides and 



fields, common throughout 111. May-July. Common 



Tickle Grass A. hyemalis (Wak.) BSP. 



5. Spikelets 2-2.5 mm long; anthers 0.5 mm long; glumes 

 ccnnivcnt in fruit, covering the grain; sandy soil in the 



n. counties. June-Aug. Northern Tickle Grass 



A. scabra Willd. 



4. Panicle open but not diffuse, 10-20 cm long, usually greenish 

 at maturity, the branches smooth; spikelets 2-2.5 mm long; 

 woods, locally throughout 111. Aug. -Oct. Autumn Bent 



Grass A. perennans (Walt.) Tuckerm. 



1. Lemma usually with a slender delicate awn about 5 mm long; 

 leaves about 1 mm wide; slender annual 10-30 cm tall; fields 



and open woods in the s. halt of 111. May-June 



A. elliottiana Schult. 



39. Cinna L. 



1. Spikelets 5 mm long, the awn 0.5-1 mm long; ]3anicle rather 

 dense, the branches ascending; moist wf)ods and borders of 

 streams. July-Sept. Wood Reed C arundinacca L. 



1. Sj)ikelets 3-4 mm long, the awn 1-2 mm long; j^anicle loose, the 

 branches spreading ov drooping; moist woods, n.e. III., not 

 common. Julv-Scpt C. latijolia ( Tiev. i Ciiiseb. 



40. Alopeciirus L. — Foxtail 



1. Spikelets 5-6 mm long; fields and waste ground, occasional; 



introd. from Eur. Meadow Foxtail A. prateiisis L. 



1. Spikelets 3-4 mm long. 



