CICHORIACEAE 643 



2. T. porrifolius L. In fields and waste places, mostly escaped 

 fromgardens: Ont. to N. J., N. Car., Minn, and Colo. Native 

 of Europe. 

 Locally abundant as an escape from gardens. 



9. Leontodon L. {Taraxacum Hill.) 



Outer involucral bracts reflexed; achenes greenish brown, the 



beak 2-3 times their length. I. L. Taraxacum. 



Outer involucral bracts spreading or ascending; achenes red, the 



beak not more than twice their length. 2. L. erylhrospermum. 



i. L. Taraxacum L. Perhaps indigenous northward, southward 

 naturalized as a weed from Europe. 

 Common nearly everywhere as a weed. 



2. L. erythrospermum (Andrz.) Britton. In fields and waste- 

 places: Me. to Vt., southern N. Y. and Pa. Probably a 

 native of Europe. 



Less common than the preceding, but found in most parts of our 

 area, as a weed. 



10. Sonchus [Tourn.] L. 



Involucre glandular-pubescent; heads nearly 25 mm. high. I. 5. arvensis. 

 Involucre glabrous; heads 12-16 mm. high. 



Auricles of the leaves acute; achenes transversely wrinkled. 2. S. oleraceits. 



Auricles of the leaves rounded; achenes not transversely wrinkled. 3. 5. asper. 



1. S. arvensis L. In low grounds and on ballast: Newf. to N. J. 



and Pa., west to Minn, and Utah. Native of Europe. 



Locally abundant as a weed, especially near salt marshes; often 

 wanting. 



2. S. oleraceus L. In fields and waste places: throughout culti- 



vated N. Am. Native of Europe. 



Frequent as a weed in most parts of our area. 



3. S. asper (L.) Hill. In fields and waste places: Nearly cos- 



mopolitan. Native of Europe. 



Common throughout the cultivated part of our area. 

 5. tenerrimus L. has been collected as a waif. 



11. Lactuca [Tourn.] L. 



Pappus bright white. 



Leaves spiny-margined and often with spiny or hispid midribs; 

 flowers yellow. 



