Hall.Compositae of Southern California. 283 



121. HIERACIUM L. HAWKWEED. 



Perennial herbs, ours rough-hairy, with entire or dentate 

 leaves and small or middle-sized heads in a panicle. Involucre 

 cylindric or campanulate, its main bracts in 1 to 3 ranks with 

 shorter ones at base, destitute of thickened midribs. Achenes 

 linear, not at all narrowed above, striately ribbed. Pappus a 

 single row of fragile capillary bristles. 



One of the largest of plant genera, a majority of the species 

 European. Several of our species are but very imperfectly 

 understood. It seems quite probable that further investigation 

 will prove our nos. 3 and 5, together with H. Brandegei, to be only 

 forms of H. argutum. 



Flowers white: stems tall 1. H. albiflorum. 



Flowers yellow. 

 Stems leafy. 



Pappus rufous or brown: leaves entire 2. H. horridum. 



Pappus nearly white: leaves mostly dentate. 



Inflorescence leafy: peduncles and involucres with light-colored 



stipitate glands, or smooth 3. H. Parishii. 



Inflorescence merely bracteate: peduncles and involucres with 



black stipitate glands 4. H. argutum. 



Stems nearly naked except at base: involucre and peduncles roughened 

 by stipitate glands 5. H. Grinnellii. 



1. H. albiflorum Hook., Fl. Bor. Am. i. 298 (1834). 



Five to 9 dm. high: stems leafy below, nearly naked above, 

 ending in a panicle of white-flowered heads: herbage thickly 

 beset below with tawny bristly hairs ; glabrous above except for a 

 minute glandular pubescence and sometimes a few soft hairs on 

 the inflorescence: lower leaves oblong, narrowed at base to a 

 winged petiole, 10 to 15 cm. long, 2 to 4 cm. broad, from entire 

 to saliently repand-dentate ; upper leaves oblanceolate to linear, 

 those of the inflorescence linear-subulate: involucre about 10 mm. 

 high ; its bracts linear-attenuate : pappus dull white. 



In open pine forests of the Transition Zone, from the San 

 Jacinto Mts. north throughout the state and also in the Rocky 

 Mts. 



2. H. horridum Fries., Epic. Hier. 154 (1862). H. Breweri 

 Gray, Proc. Am. Acad. vi. 553 (1865). 



Plant 1 to 3 dm. high, with commonly numerous stems from 



