646 



CICHORIACEAE 



Locally distributed as a weed, more common in Pa. than 

 elsewhere. 



Crepis taraxacifolia Thuill., C. setosa Haller, f. and C. rigida W. &. K. have al! been 

 collected as waifs. 



13. Hieracium [Tourn.] L. 



Flowering stem leafless, or with 1-5 leaves; achenes columnar or 

 oblong, truncate. 

 Stem scapose, with a single head only; introduced; principal 



bracts in I or 2 series. 

 Heads corymbose or paniculate; principal bracts in 2-3 series. 

 Leaves coarsely dentate, narrowed at both ends. 

 Leaves denticulate or entire. 



Leaves mostly entire, spatulate to oblong; heads 

 corymbose. 

 Heads 16-25 mm. broad; flowers red or orange. 

 Heads 10-18 mm. broad; flowers yellow. 

 Glaucous, slightly hispid. 

 Densely hirsute. 

 Leaves, at least some of them denticulate, mostly 

 obovate or oval; heads corymbose-paniculate. 

 Stem glabrous, or nearly so; leaves usually 



purple-veined. 

 Stem pilose below; leaves green. 

 Flowering stem abundantly leafy at least below. 



Principal bracts of the involucre in 2-4 series; heads corym- 

 bose. 

 Principal bracts in 1 series; heads small, paniculate or race- 

 mose. 

 Achenes columnar at maturity, truncate. 

 Plant nearly or quite glabrous. 

 Plant scabrous or glandular. 

 Peduncles stout, spreading. 

 Peduncles slender, ascending. 

 Achenes spindle-shaped, or with a tapering summit at 



maturity. 11. H. Gronovii. 



1. H. Pilosella L. In dooryards and fields: Ont., N. Y., Pa. and 



Mich. Adventive from Europe. 

 Locally common as a weed. 



2. H. vulgatum Fries. In waste places: Lab. and Newf. to 



Que. and in N. Y., N. J. Native of Europe. 



Very rare as a weed near the City of New York, perhaps not 

 peristent. 



3. H. aurantiacum L. In fields, woods and along roadsides: 



N. B. and Ont. to N. Y., N. J. and Pa. Native of Europe. 

 Common, especially northward, as a pernicious weed; perhaps 

 wanting in the pine-barrens. 



9. II. paniculatum. 



10. H. scabrum. 

 7. H. marianum. 



