JfOTES OX SEDL'M 213 



south of England stations : and by the kindness of friends have 

 received other English and Scottisli gatherings. I also collected or 

 received " >S'. acre'' from stations in Belgium, France, and Grermany, 

 and from garden sources in liussia, Sweden, Holland, Italy, Austria, 

 &c. The plants were all grown in one border under similar conditions. 

 They displayed a certain amount of variation ; but I found it 

 impossible to separate them into groups — either Drucei and acre^ or 

 any other series of two or more segregates. "■Drucei'''' varied quite 

 as much as " acre,'''' and varied in the same directions ; 1 failed to 

 lind any character in any one of the series which would justify even 

 a varietal name applied in the ordinary sense. There were certainh^ 

 compact forms and lax forms, and the leaf -form varied to a certain 

 extent ; but these hailed both from the British Isles and from the 

 continent. West of Ireland seaside forms w^ere sometimes very large 

 and lax as collected, but they lost this character when grow^n dry. 

 Compact forms from limestone rocks in central Ireland compared 

 •fresh wath German acre were indistinguishable. 



It may be that I am not gifted with a critical eye ; but I would 

 suggest that many of the European species of Hedum — for instance, 

 8. album, S. anopetalum, S. dasyphyllum, S. rejlexum, to quote 

 familiar examples — display a far wider range of variation than is 

 found in S. acre (including Drucei) ; many of the forms of these 

 have a distinct geographical range ; and until there is some agreement 

 among botanists that each of these should be divided into a number 

 of species, it seems to me only misleading to create a " species " out 

 of Drucei. 



No doubt it will be shown eventually that in the case of a large 

 number of our plants the British forms diifer slightly from continental 

 types; it would be surprising if this were not so, in view of the 

 length of the period of their isolation, and the difference of the 

 climatic conditions under w^hich they live. Similar differences no 

 doubt exist as between the English and the Irish floras — Mr. Moyle 

 Rogers has remarked that Irish Brambles seldom match satisfactorily 

 with the English plants. The study of these incipient variations, 

 where perhaps we see species in the making, is full of interest, and 

 there is no more important branch of field botany. But I think one 

 may without offence protest ugainst the use of binominals for plants 

 displaying these slight divergences from type, at all events in a genus 

 where the great majority of the species are distinct and well defined. 

 Even though we may not be able to define what we mean by a species, 

 binominals are yet used by general agreement in a certain sense ; and 

 their employment in the case of plants showing differences which 

 most botanists would consider sub-varietal or less, will hinder rather 

 than help the progress of systematic botany. 



Sedum PRUiXATrM Brotero, Flor. Lusit. ii. 209 (1804). 



This plant, one of the most interesting and distinct of European 

 Sedums, was long confused with S. riijyestre L. (aS'. elegans Lej.), 

 but several writers during the last thirty j^ears — e. g. Mariz in Bol. 

 Soc. Broteriana, vi. 21, 1888; R. P. Murray in Journ. Bot. xxvii* 

 141, 1889 ; Rouv, Illustr. PI. Eur. Rar., fasc. x. 77 ; Rouv & Camus, 



