1016 



COMPOSITAE 



Hieracium 



50 



Map 2235 



Prenanthes aspera Michx 



6. Prenanthes crepidinea Michx. Map 2236. Very local throughout the 

 state. In addition to the counties shown on the map it has been reported 

 from Carroll, Clark, Fayette, Franklin, Tippecanoe and Wabash Counties. 

 All of my specimens with one exception are from the alluvial banks of 

 streams. I have never seen more than one specimen at a place. 



Western N. Y. to Minn., southw. to Ky. and Kans. 



9607. HIERACIUM [Tourn.] L. Hawkweed 



Leaves all basal; flowers on a scape, orange 1. H. aurantiacum. 



Leaves mostly cauline. 



Cauline leaves more than 20, usually 25-45, all sessile, the margins coarsely dentate, 

 the teeth usually 1-5 mm long; basal leaves without long, margined petioles; 

 mature heads large, usually more than 15 mm wide; plants restricted to the 



northern part of the state 2. H. canadense. 



Cauline leaves fewer than 20, their margins entire or merely denticulate; mature 

 heads mostly less than 15 mm wide; plants not restricted to the northern part 

 of the state. 

 Mature achenes narrowed at the summit. 



Pubescence of the lower part of the stem and lower leaves spreading, the hairs 

 generally much less than 5 mm long; inflorescence racemosely paniculate; 



achenes mostly 3-3.75 mm long 3. H. Gronovii. 



Pubescence of the lower part of the stem and lower leaves appressed, the hairs 

 mostly 5-15 mm long; inflorescence corymbose-paniculate; achenes mostly 



3.5-4 mm long 4. H. longipilum. 



Mature achenes not narrowed at the summit. 



Inflorescence glabrous or with a few glandular hairs at the summit of the pedicel 



and on the involucre; cauline leaves narrow-oblong, acute; flowers 12-20; 



pedicels slender. 



Cauline leaves 1-3 (plants probably scapose with large cauline bracts); basal 



leaves generally purple-veined and purplish; inflorescence a loose, divided 



corymb 5. H. venos am. 



Cauline leaves usually more than 10, basal leaves not purplish; inflorescence 



an elongated, lax panicle 6. H. panicirfatum. 



Inflorescence densely glandular-pubescent; flowers mostly 40-50; pedicels stout; 

 achenes 2-2. ."> mm long; cauline leaves elliptic, obtuse 7. H. scabrum. 



