CICHORIACEAE. 
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6. Lactuca spicata (Lam.) Hitchk. (L. leucophaea A. Gray) In moist 
ground from Newf. and Man. to N. C. and Colo.—Boulder; Steamboat 
Springs. 
1 6. SONCHUS L. Sow-thistle; Milk-thistle. 
Involucres glandular-pubescent; heads about 25 mm. high. 1. .S', arvensis. 
Involucres glabrous; heads about 15 mm. high. 
Auricles of the leaves acute; achenes transversely wrinkled. 2. .S', oleraceus. 
Auricles of the leaves rounded; achenes not transversely wrinkled. 
3. .S', asper. 
1. Sonchus arvensis L. In fields from Newf. and Minn, to N. J. and Colo.; 
also on the Pacific Coast; introduced from Europe.—Walsenburg. 
2. Sonchus oleraceus L. In fields and waste places from N. S. and Wash, 
to Fla. and Calif.; introduced from Europe.—Alt. 5000 ft.—Ft. Collins. 
3. Sonchus asper (L.) All. In waste places and fields from N. S. and B. C. 
to Fla. and Calif.; introduced from Europe.—Alt. 4000-8000 ft.—Along Un- 
compahgre River, near Ouray; Cerro Summit; Glenwood Springs. 
