1060 



D is a fertile stem, measuring thirty-seven inches in length, and, at 

 its broadest portion, when pressed flat, about four lines in breadth. 

 It has twenty-five nodes, the first to eleventh of which inclusive are 

 branchless ; the twelfth has two branches ; the thirteenth, three ; the 

 fourteenth, eight; the fifteenth, sixteenth, and seventeenth, each four- 

 teen ; the eighteenth, eleven ; the nineteenth, twelve ; the twentieth, 

 fifteen ; the twenty-first, thirteen ; the twenty-second, sixteen ; the 

 twenty-third and twenty-fourth, ten each ; the twenty-fifth, none : 

 total number of branches, one hundred and forty-two, of which those 

 of the uppermost whorl reach to the base of the spike. 



The localities of E. fluviatile, so far as they are known to me, are 

 as below. Probably it will be found to be not unfrequent throughout 

 Britain, when it becomes better known, though less general than E. 

 limosum : — 



Scotland : — Dumbarton ? Inverarnar, at the head of Loch Lomond, 

 C. C. Bahington. England : — (Lake) Lancashire : Silverdale (a 

 polystachion state) ! H. Seehohm. Yorkshire : Ponds near Thirsk and 

 Topcliff'e, abundant !! and near Castle-Howard ! H. Ihholson. Cam- 

 bridgeshire : Ely, C C. Bahington. 



Now that the Equisetum fluviatile of Fries, no longer vaguely 

 " reported as a native " upon uncertain authority, or " ambiguous 

 otherwise," is clearly ascertained to be an inhabitant of Britain, it 

 becomes desirable to reopen the questions previously brought under 

 discussion in the ' Phytologist ;'* and to inquire, in the first instance, 

 whether it is distinct, as a species, from the plant of general occur- 

 rence throughout Britain, issued by Fries in his Fasciculi as E. limo- 

 sum ; figured by Smith, in ' English Botany ,'t under the same name ; 

 and by Newman, in his ' History of British Ferns,':|: under that of E. 

 fluviatile : and, secondly, what is the correct nomenclature of each 

 of the supposed species. To the first question, it is impossible to 

 give a decisive answer ; and it is a matter respecting which much dif- 

 ference of opinion may, and probably will, exist. So far as I am 

 aware, in Scandinavia alone have the distinctions between them been 

 clearly pointed out ; and consequently the botanists of that country 

 have enjoyed the best advantages for forming a decision respecting 

 them. As has been already explained in the ' Piiytologist,'§ we are 

 informed by Fries, in the ' Summa Vegetabilium,' that although nearly 



* Phytol. iii. 1, 77, 85. \ E. Bot. t. 929. + Hist. Brit. Ferns, 2nd ed. p. 51. 

 § Phytol. iii. 3, in an article by Mr. H. C. Watson, defending the correctness of 

 the position of E. fluviatile in the second edition of the ' London Catalogue.' 



