486 



THE COMPOSITE FAMILY. 



XXXIY. SOWTHISTLE. SONCHUS. 



Erect, leafy herbs, either glabrous or with more or less glandular 

 hairs on the panicles ; the leaves usually pinnately lobed or coarsely 

 toothed, and clasping the stem at the base; the flower-heads in ter- 

 minal panicles, with numerous yellow or blue florets. Involucre ovoid, 

 with imbricated bracts, and usually becoming conical after flowering. 

 Achenes flattened and striate, not beaked ; the pappus sessile, of nu- 

 merous simple hairs. 



A considerable genus, spread over the temperate regions of the 

 northern hemisphere, distinguished from Lettuce by the sessile pappus, 

 from Crejpis and Ilawkweed by the flattened achenes. 



Flowers yellow. Pappus white and silky. 



Perennials. Flower-heads large. Involucres hairy at the 

 base. 

 Marsh plant, the auricles of the leaves narrow and acute 2. Marsh S. 

 Field weed, the auricles of the leaves short and broad . 1. Com S 

 Annuals. Flower-heads rather small and pale. Involucres 



glabrous 3. Common S. 



Flowers blue. Pappus of stiff, bristly hairs, of a dirty white 4. Alpine S. 



1. Corn Sowthistle. Sonchus arvensis, Linn. (Fig. 583.) 

 (Eng. Bot. t. 674.) 



Hootstock creeping. Stems 2 to 3 feet 

 high. Leaves long, pinnatifid or sinuate, 

 the lobes lanceolate or triangular, more 

 or less curved downwards, and bordered 

 by small prickly teeth ; the lower ones 

 stalked, the upper ones clasping the 

 stem with short, broad auricles. Flower- 

 heads large, of a bright yellow, in loose 

 terminal panicles ; the branches, pe- 

 duncles, and involucres more or less 

 hispid with brown or black glandular 

 hairs. Achenes striated and transversely 

 wrinkled, with a pappus of copious, 

 white, silky hairs. 



A cornfield weed, extending over the 

 whole of Europe and liussian Asia, ex- 

 cept the extreme north. Common in 

 Britain. Fl. summer and autumn. 



Fig. 583. 



