)i 



Cirsium COMPOSITAE Centaurea 



C. arvense (L.) Scop. Canada Thistle. 



Frequent weed in fields and waste places of both provinces. 

 Mid-July to early Oct. 



Var. integrifolium Wimm. & Grab. 



Occasional, in similar habitats: Rock Springs (Ce), J. J. 

 Carter, 5 July 1910 (A); 2^ mi. s. w. of Summit Bridge (NC), 

 F. M. Jones & R. R. Tatnall, 5020, 3 June 1942 (T, A). 



Onopordum L. Scotch Thistle. 

 O. Acanthium L. 



One collection: waste ground, Centreville (NC), Commons, 11 

 Aug. 1874 (A). Nat. from Europe. 



Centaurea L. Star Thistle. 

 C. Jacea L, 



Occasional, in waste ground: Coldwell Corners (NC), R. R. 

 Tatnall, 904, 30 May 1930 (T, G); roadside bank, Augustine 

 Cutoff, Wilmington, R. R. Tatnall, 5032, 29 July 1942 (T, A); 

 roadside 1.2 mi. w. of Newark (NC), G. R. Proctor, 1125, 12 Aug. 

 1944 (P). Nat. from Europe. 



C. Cyanus L. Corn Flower. Bachelor's Button. 



Frequent escape from cultivation, in fields and on roadsides. 

 Late May to early June. Introd. from Europe. 



C. nigra L. Knapweed. 



Occasional, in fields and on roadsides: Chestertown (Ke), E. G. 

 Vanatta, 4 Aug. 1904 (A) ; railroad bank, Wilmington, R. R. Tatnall, 

 1185, 18 June 1931 (A, G, T); Shallcross Ave. near Van Buren 

 Street, Wilmington, R. R. Tatnall, 5063, 22 Aug. 1943 (T). Nat. 

 from Europe. 



V C. maculosa Lam. 



Occasional, in sandy fields and on roadsides. Coastal Plain 

 near Hurlock (Do), R. R. Tatnall, 391, 29 June 1929 (T, P, G) 

 4 mi. e. n. e. of Felton (K), R. R. Tatnall, 1882, 18 June 1933 (T, G) 

 roadside just s. of Frederica (K), R. R. Tatnall, 2753, 31 Aug. 1935 



(T). Adv. from Europe. S \A fi^'^-'^ 



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