NOTES ON DR. FOCKe's RUBI EUROP^I 203 



frequent ; and I regret that I cannot refer fully to this part of his 

 work. But the following paragraph is so remarkable that the 

 readers of the Journal may be glad for me to quote it in full : — 

 " Conjecturae do originehybridogena nonnullorumKuborum Vestitis 

 similium. Buhus adscitus et B. vestitns, simili modo ac Bubi 

 Suberecti, gregem naturalem bene distinctam constituunt. Eepe- 

 riuntur vero species complures nonnullis characteribus ad Vestitos, 

 aliis ad diversos Bubos vergentes. Quaeritur anne tales species 

 ambigentes originis hybridogenic sint, praecipue in aevo diluviano 

 vel pliocasno ortae. Illis temporibus nondum species nobis cog- 

 nitae hodiernae floruerunt, sed formae atavaB, quarum proles mutata 

 et genuina et hybridogena nunc Europam incolit." This is fol- 

 lowed by the heading " Species et prospecies, quarum origo 

 hybridogena e Eubis Vestitis suspicari potest," and a table, from 

 the fourteen lines of which the following are examples : — 



Series vel 

 " Species atavje (vel recentes) parentes. Species hybridogenae. subseiies. 



" B. adscitus et B. sulcatus. B. leucandrus. Silvatici. 



B. vestitns et B. sulcatus. B. macrophyllus. ,, 



„ B. vulgaris. B. pyramidalis. Vestiti. 



„ B. egregius. B. vmcronatus. Sevii-Egregii. 



„ B. ccBsius. B. Balfourianus. Corylifolii." 



B. gynmostachys Genev. This name, given as a variety of 

 B. leucostachys in my Handbook and in Lond. Cat. ed. x., is now, 

 contrary to Dr. Focke's earlier views (for which see Journ. Bot. 

 1905, pp. 76, 202), considered by him too indefinite and unsatis- 

 factory ; while J. Lange's B. macrothyrsus (which we have treated 

 as a synonym of B. gymnostachys) takes its place, and becomes a 

 numbered " species." He says, with reference to B. gymno- 

 stachys, " Vidi specimina Genevierii a B. macrothyrso non dis- 

 tinguenda, sed botanici Gallici auctorem diversos Eubos sub hoc 

 nomine comprehendisse asserunt." And, again, under B. macro- 

 thyrsus, he adds, " Aspectus hujus plantae ab illo B. vestiti valde 

 discrepat, sed notae ditferentes vacillant. E ramis exsiccatis 

 facile ' species ' artificiales construuntur, sed specimina Britan- 

 nica, Hersynica et Holsatica satis congruere videntur." With us 

 the name gymnostachys has certainly not hitherto been applied to 

 one form only, but has included slightly varying forms of B. leuco- 

 stachys, together with our strongly marked and highly glandular 

 Bangor (Carnarvon) plant, which is clearly indistinguishable from 

 Lange's B. macrothTjrsus as supplied to me from " near Kiel, 

 Holstein," by Messrs. Friderichsen and Gelert. Quite the same 

 plant was found in Northants by Mr. Druce last year, and my 

 herbarium contains several other sheets from English counties — 

 from Yorks and Flint to Somerset, Dorset and Devon. So the 

 name gymnostachys may well be dropped from our Bubus list, 

 and macrothyrsus substituted for it, either (preferably, I think) as 

 a strongly marked variety of B. leucostachys, or in an independent 

 position, as in Bubi Europm. 



B. leucanthemus P. J. Muell. ? There seems to be no reference 



