DICOTYLEDONOUS PLANTS 235 



those of the hranches reduced to bracts. Flowers very showy, 

 usually bright blue, rarely fjinkish-white. Introduced from Europe ; 

 a troublesome weed in grass-lands and common in waste places, 

 particularly in New England. 



XIV. HIERACIUM, L. 



Perennial herbs, often covered with glandular or star-shaped 

 hairs ; juice milky. Leaves alternate. Heads solitary, or in 

 corymbs or panicles ; bracts of the involucre many, overlap- 

 ping, unequal; receptacle flattish, naked, pitted. Corollas 

 yellow, rarely orange; arms of the style slender and upper 

 part of the style hairy. Akenes angled or grooved, not beaked. 

 Pappus hairs in a single row, simple, stifP, tawny, or brownish, 

 brittle. 



1. H. venosum, L. Rattlesnake Weed. Stem scape-like, 

 usually leafless or nearly so, smooth, 1-2 ft. high. Root-leaves 2-5 

 in. long, obovate or ovate-oblong, generally purple-veined. Heads 

 rather large, yellow, in a loose panicled corymb. Dry hills and 

 roadsides, and in pine woods E. 



XV. I-EONTODON, t. 



Perennial, scape-bearing herbs; juice milky. Leaves all 

 radical, toothed or pinnatifid, often runcinate. Heads on 

 simple or branched scapes, yellow; bracts of the involucre 

 many, in several rows, the anther smaller; receptacle flat, 

 naked. Arms of the style linear, obtuse, hairy. Akenes cylin- 

 drical, grooved, transversely wrinkled; beak short; pappus 

 hairs stiff, in 1 or 2 rows. 



1. L. autumnalis, L. Scape usually branching, 5-15 in. high, 

 bracted; peduncles enlarged above. Rootstock truncate. Heads 

 1^1 in. or more in diameter ; involucre top-shaped or bell-shaped. 

 Pappus of a single row of tawny hairs. Fields and roadsides, 

 especially N". E. Introduced from Europe. 



XVI. TARAXACUM, Haller. 



Stemless, perennial or biennial herbs. Leaves in a flattish 

 tuft, pinnately cut or runcinate (Fig. 38). Head many- 

 flowered, large, solitary, yellow, boriie PR a hollow scape, whicli 



