1918] The Grasses of Illinois 355 



OGLE CO. Without locality, M. S. Behh; Oregon, Waits, Sept., 1388. peoria co. 

 McDonald, Oct., 1904; Peoria, Brendel. stark co. Duncan, V. H. Chase, Sept., 

 1906. WILL CO. Marley, Uill, Sept., 1895. 



Sporobolus vaginaeflorus (Torr.) Wood 

 Sheathed Rush Grass (Fig. 164) 



Vilfa vaginaeflora, Lapham '57, 544, 563 (Plate 1, Fig. 5) ; Babcock '73, 96; 

 Flagg '78, 280; Brendel '87, 63. Sporobolus vaginaeflorus, Higley and Kaddin 

 '91, 142; Huett '97, 219. 



Culms 8 to 24 inches tall, ■ smooth ; sheaths usually all inflated, 

 smooth ; blades a little longer than the sheaths, very narrow, usually 

 involute, rough on the upper surface and pubescent near the base; 

 lateral panicles usually inclosed in the inflated sheaths, the terminal 

 ones usually free; spikclets 3.5 to 4 mm. long, the glumes usually 

 white, the lemma dark colored and always pubescent. 



This species resembles 8. neglectus, but is usually larger and is 



easily recognized by the spikelets. It grows in dry, sandy soil. 



ILLINOIS SPECIMENS : Without locality. Wolf in 1882 ; without locality, Mead 

 in 1844. CHAMPAIGN CO. Urbana, Grimes, Sept., 1916. cook Co. Lyons, Hill, 

 Auo-., 1898; Morgan Park, Chicago, 7///^, Sept., 1898; Egaleston, Hill 309 in 1898. 

 FULTON CO. Without locality, Pepoon. jo daviess CO. Without locality, Pepoon. 

 HANCOCK CO. Augusta, Mead in 1843. Henderson co. Oquawka, Patterson. 

 lake CO. Lake Zurich, Hill, Sept., 1898. menard co. Without locality. Hall. 

 PEORIA CO. Peoria, McDonald, Sept., 1900. ST. clair co. Mascoutah, Welsch. 

 stark CO. Wady Petra, V. H. Chase 1209 and 1266. avabash co. Mt. Carmel, 

 SchnecTc, Sept., 1876 and Oct., 1887. 



Two other species have been reported from Illinois, S. junceus 

 (Higley and Raddin '91, p. 42) and S.. virginica {Vilfa virginica, Pat- 

 terson '76, 49; Flagg '78, 280; Brendel '87, 88). No specimens of 

 either of these have been seen. The latter, as understood at present, 

 is a seashore rush grass with long, stout rootstocks, and is not found 

 inland. 



27.AGROSTIS L. 

 Bent Grass 



This genus includes both annual and perennial species. They are 

 distinguished by the small one-flowered spikelets in which both glumes 

 and lemma are thin, the glumes considerably the longer. The palea is 

 minute or wanting in all Illinois species but A. alba. The inflorescence 

 is always paniculate. The leaves are narrow, with conspicuous mem- 

 branous ligules. A. alba is the only species of economic importance. 



Lemma with a long awn; spikelets less than 2 mm. long. A. elliottiana 

 Lemma awnless; spikelets more than 2 mm. long. 



Palea at least half as long as the lemma. A. alba 

 Palea minute or wanting. 



Panicle branches spreading, usually whorled, the branches long and cap- 

 illary, very rough, spikelet-bearing at the tips. A. hyemalis 

 Panicle branches ascending or spreading, but not whorled, nearly smooth, 

 the spikelets not clustered at the tips of the branches. A. perennans 



