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MONOGRAPH of the BRITISH SPECIES of EUPHRASIA. 



Prefaced by an Epitome of Pkof. Wettstein's Views on the Development 



AND DiSTBIBUTION OF THE EUROPEAN SpECIES. 



By Frederick Townsend, M.A., P.L.S. 



Introductiox. 



The geuus Euphrasia has of late years received such an amount 

 of attention, and the locaHties of the various forms and species have 

 been noted to such an extent, especially throughout Europe and 

 Asia, that as a result it has been found that the species are remark- 

 ably restricted to areas of distribution. It is still more remarkable 

 that the areas of closely-allied species are not found to intersect or 

 overlap. Among such species are E. Tatarka Fisch., E. pectinata 

 Ten., E. stricta Host. They are closely allied, but their areas are 

 distinct, and do not overlap. E. Salisburi/cnsis Funk, is closely 

 allied to E. Ilhjrica Wetts., but the former does not occur within 

 the area of the latter. On the other hand, take E. minima and 

 E. stricta, E. nemorosa and E. borealis. The first two are remotely 

 allied, but the area of the first is found within the area of the 

 second. The latter two are also remotely allied, but the area of 

 the one intersects the area of the other. Intermediate forms may 

 and do occur, but they are the exception and not the rule. The 

 botanist is therefore forced to recognize that certain forms have 

 become and are more or less stable, and to such an extent that they 

 may be treated as permanent enough to constitute and be reckoned 

 and described as species. 



In this paper I propose to preface a description of the species 

 indigenous to the British Isles by notes on the various organs, and 

 on the history of the evolution, formation, and distribution of the 

 species as given in Prof. Wettstein's monograph of the genus. No 

 one has done more towards the elucidation of the genus than Prof. 

 Wettstein, whose monograph exhibits great sagacity, great ability, 

 united with the most careful and wide observation. He has culti- 

 vated many of the species, has sifted records, examined herbaria, 

 and elaborated the synonymy. He has shown that while that close 

 observer M. Jordan recognized several distinct species which 

 western botanists were not acquainted with, he gave new names 

 to some which had already been recognized and named by earlier 

 botanists. The adoption of M. Jordan's names by recent observers 

 has led to considerable confusion, and contributed to induce many 

 to believe that the species so run into one another as to makp it 

 impossible and even a waste of time to enumerate and describe 

 them. As instances I may refer to three marked species to which 

 M. Jordan gave new names, but which Prof. Wettstein has shown 

 to have been already known and named. These are — E. majalis 

 Jord. = E. pectinata Tenor., E. ericetorum Jord. = E. stricta Host., 

 E. puberula Jord. = E. Tatarica Fisch. 



I have done my best to put the reader in possession of the salient 

 features of Prof. Wettstein's views, and of his methods of reasoning, 



Journal of Botany. — Vol. 35. [Sept. 1897.] v 



