40 ANNALS OF SCOTTISH NATURAL HISTORY 



and R. involuta, Sm., which are hybrids. Among the 

 varieties of Rosa included in the eighth edition of the 

 " London Catalogue of British Plants " one sees the names of 

 R. sylvicola, Desegl. and Rip., R. collina, Jacq., R. Kosdnciana, 

 Besser, and R. marginata, Wallr. ; but these should be ex- 

 cluded from the list of the roses of England, since they are 

 hybrids of R. gallica, crossed with R. rubiginosa and R. 

 canina. 



Despite the very limited number of species, among 

 which are two of subordinate rank R. obtnsifolia and R. 

 glauca the future monographer will nevertheless have a 

 laborious task to fulfil, a task that will demand years of 

 researches out of doors and in herbaria. The geographical 

 distribution will demand on its part much care and circum- 

 spection, because of the confusions that have been or may be 

 made between certain species. Thus R. mollis has some- 

 what frequently been confounded with R. tomentosa, and 

 certain varieties of R. glauca with glandular leaves have even 

 been placed under R. mollis. In herbaria it is not uncom- 

 mon to see certain varieties of R. micrantha named R. rubi- 

 ginosa, R. glauca in its glabrous forms, or when pubescent 

 (R. coriifolid), may be confounded with varieties of R. canina. 

 It should be remarked that R. glauca presents varieties or 

 sub-varieties parallel to those of R. catii/ia that I have 

 classed artificially under the group names R. lutetiana, Lem., 

 R. dumalia, Bechst, R. andevagensis, Bast., R. verticillacantha, 

 Merat, R. scabrata, Crep., R. Blondeana, Rip., R. dumetorum, 

 Thuill, and R. Deseglisei, Bor. Even R . arvensis has not 

 quite escaped this confusion, since w r e see that its variety 

 gallicoides (R. gallicoides, Deseglise) has been referred to R. 

 stylosa. 



To settle the distribution of the species the monographer 

 must then be very careful ; he ought to verify everything, 

 under risk of committing such errors. 



Watson, in his " Topographical Botany," has endeavoured 

 to determine the geographical distribution of the Roses of 

 England and Scotland ; but his work, based especially upon 

 documents printed in floras and in catalogues, cannot inspire 

 very great confidence in presence of the confusions of species 

 that have been grievously fallen into by the authors of the 



