108 ALIEN FLORA OF BRITAIN 



as growing in natural surroundings, it can hardly be 

 admitted to a place in our native list in the face of its 

 geographical distribution. 



Centaurea calcitrapoides, L. Native in the Medi- 

 terranean region. Once recorded as an introduced 

 casual in England. 



Centaurea centauroides, L. Indigenous in the dry 

 mountain pastures of South-East Europe and a weed 

 of dry arable land over a rather wide area. It has 

 been noticed in England as a casual (presumably grain- 

 introduced). 



Centaurea Cyanus, L. It appears to be indigenous in 

 woods in Southern Russia and Asia Minor, and it has a 

 wide range as a cornfield weed in Europe. In Southern 

 and Mid-England it is often plentiful among cereal crops,, 

 but further north it becomes scarce. 



Centaurea dealbata, Willd. A native of rocky places 

 in the Orient. Cultivated in gardens in England, and 

 occasionally reported as an escape from horticulture. 



Centaurea depressa, Bieb. A native of Asia Minor, 

 better known as a cornfield weed in South-East Europe. 

 Communicated by Mrs. Baker from Oulton Broad. In- 

 troduced with Eastern barley. 



Centaurea diffusa, Lam. Indigenous in dry sandy 

 situations in South-East Europe and Asia Minor, and 

 a cornfield weed in the same region. Once or twice 

 noticed in connection with introduced grain. 



