COMPOSITE. 



under the name of Midgedium, will scarcely hold 

 exotic species of blue Sowthisttes. 



489 

 in some other 



XXXV. DANDELION. TAKAXACUM. 



Herbs, with a perennial rootstock, radical leaves, and radical pe- 

 duncles, with single heads of yellow flowers. Involucres of several 

 nearly equal, erect inner bracts, and several imbricated outer ones. 

 Receptacle without scales. Achenes tapering into a long slender beak, 

 with a pappus of numerous simple hairs. 



A widely diffused genus, of which all the described species may per- 

 haps be considered as varieties of a single one, differing from Sawkbit 

 in the simple hairs of the pappus, from Crejois chiefly in the leafless 

 simple peduncles. 



1. Common Dandelion. Taraxacum Dens-leonis, Desf. 

 (Fig. 587.) 



(Leontodon Taraxacum, Eng. Bot. t. 510.) 



The rootstock descends into a thick 

 tap-root, black on the outside, and very 

 bitter. Leaves varying from linear- 

 lanceolate and almost entire to deeply 

 pinnatifid, with broad triangular lobes 

 usually pointing downwards, the ter- 

 minal one larger, obovate or acute. Pe- 

 duncles 2 to 6 or 8 inches high. Involu- 

 cral bracts linear, often thickened to- 

 wards the top, or with a tooth on the 

 back below the point. Achenes slightly 

 or not at all compressed, striated, 

 marked upwards with short pointed as- 

 perities, the beak two or three times as 

 long as the achene itself. lg ' ° l ' 



In meadows and pastures, cultivated and waste places, throughout 

 Europe, Eussian and central Asia, and northern America to the Arctic 

 regions, and now a troublesome weed in almost all cultivated parts of 

 the world. Among the numerous forms which have given rise to the 

 distinction of a considerable number of supposed species, the most re- 

 markable British ones are the common _D., with pinnatifid leaves and 

 the outer involucral bracts much recurved, and the marsh D. (T. 

 palustre, Eng. Bot. t. 553), with narrow leaves nearly entire or sinuate, 

 and the outer involucral bracts scarcely spreading at the tips. 



