COMPOSITE FAMILY 251 



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

 bracted; peduncles enlarged above. Rootstock truncate. Heads 

 lj-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. Naturalized from Europe. 



XVII. TARAXACUM Haller 



Stemless perennial or biennial herbs. Leaves in a flattish 

 tuft, pinnately cut or runcinate. Head many -flowered, large, 

 solitary, yellow, borne on a hollow scape, which is short at 

 first but lengthens after flowering. Involucre composed of a 

 single row of long, erect inner scales, and a set of much shorter 

 ones outside and at the base of the former ones. Akenes cylin- 

 drical or spindle-shaped, with 4-5 rough ribs, the apex taper- 

 ing into a bristle-like beak which bears a short, broadly conical 

 tuft of soft white hairs. 



1. T. officinale Weber. DANDELION. Outer involucre reflexed; 

 inner involucre closing over the head, after the flowers are withered, 

 and remaining shut for some days, then opening and allowing the 

 akenes to form a globular head. Root stout, bitter, medicinal. Young 

 leaves eaten as a pot-herb (" greens ") in spring the plant often cul- 

 tivated for the leaves by market-gardeners. 



xvm. SONCHUS L. 



Annual or perennial. Leaves mostly toothed or pinnately 

 cut, prickly margined. Heads in corymbs or panicles ; bracts 

 in several series, the outer shorter ; receptacle naked. Flowers 

 yellow, rays truncate, 5-toothed at the apex. Akenes oval to 

 oblong, compressed, ribbed, truncate at the apex; pappus of 

 numerous soft white hairs.* 



1. S. oleraceus L. Sow THISTLE. Annual; stem erect, branched, 

 smooth, 2-6 ft. high. Leaves spiny-toothed, the lower long-petioled, 

 very irregularly cut or pinnatifid, the upper clasping by an eared 

 base. Involucre downy when young. Akenes channeled and trans- 

 versely wrinkled. In waste places on very rich soil.* 



2. S. asper Vill. SPINY Sow THISTLE. Annual ; stem erect, 

 smooth, branched but little, 2-6 ft. high. Leaves undivided, spatu- 

 late to oblanceolate, fringed with spiny teeth; the lower narrowed 

 into a petiole, the upper clasping by an eared base, the ears rounded. 



