1918] The Grasses of Illinois ' 349 



of the continent. The introduced species, P. pratcnse, is cultivated 

 everywhere in the state for hay. It is a perennial grass, growing in 

 tufts, with long, cylindrical, spike-like panicles. The spikelets are onq- 

 flowered, flattened, and closely crowded. The Icnnna is thinner than 

 the glumes and transparent. The leaves are long and flat, the ligules 

 membranous, from 2 to 3 mm. long. 



Phleum pratense L. 

 Timothy. Herd's Grass (Fig. 150) 



Culms 1.5 to 3.5 feet tall, erect, smooth, enlarged, and bulbous at 

 base ; sheaths smooth ; blades 3 to 12 inches long, 4 to 6 mm. wide ; 

 spikelets 2 to 5 mm. long, usually 3 mm. ; glumes keeled and about 

 twice as long as the lemma, the midnerve produced into a short awn 1 

 to 2 mm. long. 



This species grows in meadows all over the state. , 



25. ALOPECURUS L. 



Foxtail Grass 



This genus includes plants with the inflorescence in spike-like pan- 

 icles which somewhat resemble timothy, or herd's grass, Plileum pra- 

 iense. The spikelets are one-flowered, flattened, with keeled glumes. 

 The lemma is thin and transparent and bears an awn near the base. 

 There are two species commonly found in Illinois. A third species, A 

 pratensis, is mentioned by Lapham, Patterson, Flagg, and Huett as 

 having been cultivated in Illinois. No Illinois specimens have been 

 seen, however, except from the University experimental plots. It is 

 included in the key, so that if any specimens are found, they may be 

 identified. 



Spikelets 4 to 6 mm. in length. A. pratensis 



Spikelets never more than 3 mm. in length. 



Awn scarcely exceeding the spikelet and not extending over 1 mm. beyond it; 



spikelets 2.5 to 3 mm. long. A. nristnlatus 



Awn exceeding the spikelet by the length of the glume or more; spikelets 2 



mm. long. A. geniculatus 



Alopecurus aristulatus Michx. 

 Wild Water Foxtail. Floating Foxtail (Fig. 154) 



Alopecurus aristulatus, Lapham '57, 544, 562 (Plate 1, Fig. 3) ; Flagg '78, 

 280. Alopecurus tjeniculatus var. aristulatus, Brendel '87, 63; Higley and Kaddin 

 '91, 142; Huett '97, 129. 



Culms slender, smooth, 6 inches to 2 feet tall, usually erect; 



sheaths smooth ; blades roughened, 1 to 6 inches long, 1 to 4 mm. wide ; 



spikelets about 2 mm. long, the awn very short, not extending beyond 



the panicle. 



