DICOTYLEDONOUS PLANTS 935 
those of the branches reduced to bracts. Flowers very showy, 
usually bright blue, rarely pinkish-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, stiff, 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. LEONTODON, L. 
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 eniarged above. Rootstock truncate. Heads 
13-1 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, borne on a hollow scape, which 
