NOTE OX CENTAUKEA 341 



At present, it would seem that a good deal of field work is neces- 

 sary before an approximately accm-ate knowledge of the various forms 

 of Centaurea can be obtained and their distribution worked out. 

 Botanists who have the opportunity could render important service 

 in investigating whether or not C. Jacea is an aboriginal species in 

 the various localities from which it has been recorded. All specimens 

 of alleged C. Jacea require very careful examination, as it appears 

 certain that allied forms have been erroneously recorded under this 

 name. I here particularly refer to Sussex specimens of G. Jacea, 

 various examples so named having recently passed through my hands. 

 Equally important, perhaps, is an enquiry into the plants recorded by 

 British botanists as C. nigra var. decipiens, as forms nearer related 

 to G. Jacea, and even C. Jacea itself, have been recorded under 

 this name. 



It may be thought impossible that G. Jacea could pass as G. nigra 

 var. decipiens, but the following shows that it has done so. In 

 Mr. H. W. Monckton's compact little Flora of the Bagshot District 

 (noticed in this Journal for 1916, p. 94), C. nigra var. decipiens 

 (Thuill.) is recorded from the Upper Bagshot sands of Wellington 

 College, Berkshire. Mr. C. E. Salmon has in his herbarium a sheet 

 of Mr. Monckton's plant, which I have seen. These specimens are 

 not what usually pass with British botanists as nigra var. decipiens^ 

 nor do they agree wdth French conceptions of Thuillier's plant. 

 Hearing of my interest in the matter, Mr. Monckton kindly sent me 

 a few dried specimens bearing the same name and from the identical 

 locality, with a note saying that '* this form grows in considerable 

 abundance at Wellington College on the Bagshot Sand ; it is most 

 abundant on the Upper Bagshot Sand but spreads on to the sandy 

 upper part of the Middle Bagshot Sand as well." To my surprise, 

 the examples that reached me were unmistakable G. Jacea L. During 

 the past summer I have received fresh flowering specimens from 

 Mr. Monckton, who has kindly given me much information about the 

 present and past conditions of the localit3\ Referring to the speci- 

 mens sent to me, Mr. Monckton wrote " they are what I meant by 

 G. nigra var. decipiens in my Flora of the Bagshot District. They 

 occur in a limited area here, say, in the square mile between Crowthorne 

 Church and the South -Eastern Railway in the eastern corner of Berk- 

 shire. At the present they are in flower by the hundred or perhaps 

 by the thousand. The ordinary G. nigra is also present and is 

 frequent all around here, both on the Bagshot Sand and on London 

 Clay, but I only find the species of which I sent you specimens on 

 Bagshot Sand and at the particular place above mentioned. I see 

 G. nigra b. decipiens is mentioned in the Sixth Annual Report of the 

 Wellington College Natural Science Society published in 1876 ; it 

 may occur in earlier Reports, but I have not such at hand." 



As the Gentaurea was so abundant, and no doubt was expressed 

 as to its status as a British plant, I visited the locality to observe 

 under what conditions it occurred. The plants grow chiefly along 

 the border of a road, among turf, etc., for a distance of about half a 

 mile. The road is bounded at intervals by strips of turf of varying 

 extent, but chiefly by shnibs and undergrowth of the heath-forma- 



