296 A GUIDE TO THE WILD FLOWERS 



stem, or solitary and essentially stalkless, about 13^ in. wide. 

 Common as a weed nearly throughout the area. Native of 

 Europe. August. Fig. 909. 



QIC. Oyster Plant. Tragopogon porrifolius. A curious stiff 

 European plant, 1-4 ft. high, with lance-linear, toothless 

 leaves. Flowers purple, the heads on hollow, thickened stalks. 

 The bracts beneath each flower head much exceed the rays 

 and are long, slender and pointed. In fields and waste places, 

 mostly as an escape from cultivation, Ontario to No. Caro- 

 lina and westward. June-October. Fig. 910. A related species 

 with yellow flowers, T. pratensvs, is found in similar situa- 

 tions. 



911. Sow-thistle. Sonchus oleraceus. A mostly unbranched 

 erect stiff, annual weed, 2-6 ft. high. Lower leaves much 

 cut or incised, the segments toothed with almost spiny teeth, 

 and the terminal leaf -segment almost triangular. Upper stem 

 leaves deeply divided, stem-clasping at the base. Flowers yel- 

 low, the heads about 2 in. wide, and usually numerous. Com- 

 mon nearly throughout North America. Native of Europe. 

 June-October. Fig. 911. 



912. Cynthia. Cynthia virginica. (Krigia amplexicaulis.) A 

 perfectly smooth, bluish-green perennial, 1-2 ft. high. Leaves 

 all basal except one on the stem, shallowly and remotely 



