1918] The Grasses of Illinois 409 



This grass is exceedingly common in fields, especially among culti- 

 vated crops, along roadsides, and in waste places. The internodes of 

 the creeping rootstock are bright greenish yellow. Joints of the root- 

 stock will start new plants, making the species an exceedingly hard 

 one to eradicate amongst cultivated crops. It may be destroyed by 

 thoro and persistent cultivation, exposing the rootstoeks to the sun. 

 It may also be destroyed by ploAving it under in the fall, if it is covered 

 by a depth of six or seven inches of soil. 



ILLINOIS SPECIMENS: Without locality, Vasey. champaign go. Urbana, 

 Seymour, June, 1880; Urbana, Clinton, Jane, 1897; Urbana, Waite, July, 1886. 

 CHRISTIAN CO. Taylorville, Andrews, cook co. Chicago, Babcoclc, June, 1874; 

 Evanstou, Shipman, July, 1875; Woodlawn, Chicago, Lansing, June, 1898. DU 

 PAGE CO. Naperville, Umbach, June, 1898. fulton co. Without locality, Pe- 

 poon. JO DAVIESS CO. Without locality, Pepoon. kankakee co. Kankakee, 

 Eeecher, July, 1908. mchenry co. Ringwood, Vasey. peoeia co. Peoria, Mc- 

 Donald, July, 1897. Princeville, V. H. Chase 14G3. stark co. Wady Petra, V. 

 U. Chase, June, 1907. wabash co. Mt. Carmel, Schneclc, July, 1895. 



AgTopyron smithii Rydb. 



Blue-joint. Western Wheat Grass (Figs. 270 and 271) 

 Culms stiff, erect, smooth, 1 to 5 feet tall ; sheaths smooth ; blades 

 bluish green, rough, becoming involute, 4 to 8 mm. long, 4 to 6 mm. 

 wide ; spikelets 7- to 13-flowcred, 12 to 20 mm. long ; lemmas awn- 

 pointed, faintly nerved. 



This species is found on the western prairies in alkali soil and is 

 rather common here along railway tracks. It is not a weed like A. 

 repens. It can be distinguished from that species by its blue-green 

 color and more densely flowered spikelets. 



ILLINOIS specimens: Without locality, northern Illinois, Brendel; Romeo, 

 Umbach, June, 1898. JO daviess co. Hanover, Gleason and Gates 2599. peoria 

 CO. Peoria, McDonald, July, 1901 and 1903. stark CO. Wady Petra, V. H. 

 Chase 653, 1518. will co. Joliet, Skeels 323; Mokeua, Hill 15 in 1910. 



Agropyron smitJiii molle (S. and S.) Jones. — This variety is softly 



pubescent, thus differing from the species. 



DU page CO. West Chicago, Umbach, June, 1897. 



Agropyron tenerum Vasey 

 Slender Wheat Grass (Fig. 272) 



Culms erect, stiff, smooth, 1.5 to 3 feet tall; sheaths smooth; blades 

 flat or involute when dry, rough, 3 to 10 inches long, 2 to 4 mm. wide ; 

 spikelets 3- to 5-flowered; lemmas 10 to 12 mm. long, awned or awn- 

 pointed, rough on the margin and toward the top. 



This species has no running rootstoeks. It is found mostly in dry 

 soil, where it grows in large bunches. 



COOK CO. Chicago, A. Chase 1132. stark co. South of Wady Petra, V. II. 

 Chase, 1161. 



