252 WEEDS OF THE FARM AND GARDEN 



Dandelion (Taraxacum officinale, Weber.). A smooth, 

 or, at first, pubescent perennial ; head many-flowered 

 borne on a slender, hollow scape ; root-leaves pinnatifid 

 or runcinate; involucre double, the outer of short scales,, 

 the inner long, linear, erect in a single row, but closing 

 after flowering; fruit ripens close to ground, the hollow 

 scape elongating, the whole involucre then becoming 

 reflexed, thus permitting the wind to scatter the "seeds ;" 

 achenes ("seeds") oblong, long beaked, the beak two or 

 three times as long as the remainder of the achene, bear- 

 ing at the end long, soft, 

 white capillary threads, 

 the pappus. Probably 

 native northward, but in 

 the southern states natu- 

 ralized from Europe. 

 Common also in Asia; a 

 cosmopolitan weed. Al- 

 lied to the above species 

 is a red seeded dandelion 

 which is not uncommon 

 in eastern North Amer- 

 ica. It is very much like 

 the common dandelion 

 but has narrow "seeds" 

 that are a bright red or 

 red brown color; pappus 

 a dirty white. 



Field Sow Thistle (Son- 

 chus arvensis, L.). A 

 Fig. i6oa. Common sow thistle glabrous perennial, pro- 

 (Sonchus oleraceus). (Ada Hay- d uc j n g <j ee p creeping 



rootstock, stem leafy, 



branched, basal leaves runcinate-pinnatifid, spiny 

 toothed, clasping by a heart-shaped base ; flowers yellow ; 

 achenes transversely wrinkled. Common in the eastern 



