88. PTERIDIOIDES. 309 



wards or downwards into Aberdeenshire, does not clearly 

 appear. Mr. Brichan writes thus : — " The three i)lants 

 are found at various parts along the course of the Dee, 

 within the j)arish of Banchory, extending over a space of 

 six or seven miles in length. There are three distinct 

 stations for E. hyemale, four for E. Mackaii, three for E. 

 variegatum, and several mtermediate spots in which de- 

 tached plants of each sj)ecies or variety, especially of E. 

 Mackaii, occur." (Phytol. i. 370). Has been supposed 

 identical with Equisetum elongatum (Willd.) and ramosum 

 Schl.) ; but this idea would seem to be now abandoned. 

 (See Brit. Flo. ed. 6, p. 583). 



1428. Equisetum variegatum, " Weber & Mohr." 

 1428, b. Equisetum Wilsoni, [Newm.) 



Ai-ea 1 * * ^ * * * * 9 10 11 12 13 14 15 * 17. 



South limit in Devon, Somerset ? — Chester, York. 



North limit in Ross, Aberdeen or Kincardine. 



Estimate of provinces 9. Estimate of counties 15. 



Latitude 50 — 58, Scottish ty]3e of distribution. 



Agrarian region. Inferagi'arian — Superagi'arian zones. 



Descends nearly to coast level (60 yards), in Peninsula. 



Ascends to 200 yards, or upwards, in Tyne province. 



Range of mean annual temperatiu'e 51 — 46. 



Native. Inundatal, Paludal. Although I possess many 

 specimens of this plant, and have seen it on the coasts 

 of Cheshire and Lancashire, I confess to still finding 

 much difficulty in tracing the distinctive limits of the 

 species. While on the one side, it makes some approach 

 towards E. palustre, in the small littoral and alpine 



