166 ^ARM WEKDS OF CANADA 



large, nearly 2 inches across, solitary at the end of the branches. 

 The seed is also similar to that of Canada Thistle, but broader, 

 more flattened, about 1/3 of an inch long, highly shiny. This 

 is not a serious pest and soon disappears when the land is put 

 under crop. 



Closely allied to these thistles are the Knapweeds (Centaur ea). 

 Common Knapweed (Centaurea nigra L.), is rather abundant in 

 meadows in the Maritime Provinces. It is a coarse perennial with 

 thistle-like flowers, over 1 inch across and 1 inches high. The 

 calyx-like whorl of bracts surrounding the flower heads is 

 spherical and composed of black-fringed scales. 



The seed (Plate 76, fig. 90) is about 1/8 inch long, half as wide, 

 tapering to the base, slightly angular, somewhat flattened and 

 the dark, shining gray surface striped lengthwise with pale 

 ridges; the whole seed is sparsely hairy. The large apical scar 

 covers the whole of the top and is surrounded by a pappus of 

 2 or 3 rows of short, flat bristles. A characteristic of this seed, 

 is the more or less hooked pointed end bearing the basal scar. 



TRIBE CICHORIEAE 

 CHICORY (Cichorium Intybus L.) 



Other English names: Wild Chicory, Wild Succory, Blue 

 Sailors. 



Introduced from Europe. Perennial from a deep, long, 

 thick root. Stems 2 to 3 feet high, branched, hairy below. Root- 

 leaves closely resembling those of Common Dandelion, 6 to 8 inches 

 long, spreading on the ground, dentate or pinnatifid with 

 the divisions directed backward; midribs hairy beneath; upper 

 leaves glandular hairy on the margins, clasping at base. 

 Flower heads bright blue, sometimes purple or nearly white, 

 about 2 inches across, composed entirely of strap-shaped flowers, 

 usually closing by noon, in stalkless clusters of 3 or 4 together 

 along the almost leafless stems. 



The seed (Plate 76, fig. 91) is 1/8 inch long, dark brown or 

 straw-coloured, mottled with brown, wedge-shaped, obtusely 



