A GUIDE TO THE WILD FLOWERS 



832. Knapweed. Ccntaurea nigra. A stiff, hairy or rough 

 European perennial, 1-2 ft. high. Leaves alternate, more or 

 less wavy margined or remotely toothed, lance-shaped or 

 lance-oblong, essentially stalkless, 3-6 in. long. Flower heads, 

 I in. in diameter, solitary at the ends of leafy branches, the 

 flowers tubular, slightly fringed, rose-purple. In waste places, 

 Newfoundland and Ontario to New Jersey and Penna. Au- 

 gust. Fig. 832. A related plant, the Corn Flower, C. Cyanus; 

 has blue and more fringed flowers. It is a European plant 

 and frequently escapes from cultivation. Called also Ragged 

 Sailor and Bachelor's-button. 



833. Flowers green, yellow, or greenish-yellow. 



Leaves lobed or toothed, broad ; not dissected or divided 



Clot-bur no. 834 



Leaves divided or dissected 

 Flower heads erect, in a flat-topped cluster .... Tansy no. 835 

 Flower heads often drooping, in long clusters, not flat-topped 

 Foliage densely white-hairy .... Beach Wormwood no. 836 

 Foliage green, or only slightly hairy 



Leaves green, the divisions nearly thread-like 



Wild Wormwood no. 837 



Leaves pale, the divisions not thread-like 



Common Wormwood no. 838 



834. Clot-bur. Xanthitim commune. One of a group of 

 species all of very similar aspect, and growing in moist open 

 places. They are erect, or sprawling annual weeds, 1-5 ft. 



