300 



This plant occurs in the North of Ireland, more particularly in the 

 counties Derry and Antrim. It was originally discovered in the year 

 1833, by Mr. Mackay, the well-known author of the ' Flora Hiberni- 

 ca,' when in company with Mr. Whitla, in Colin Glen, near Belfast. 

 Subsequently to this date it has been repeatedly observed by different 

 botanists : Mr. Moore, the talented and energetic conservator of the 

 Dublin Glasnevin Gai'den, to whom I am indebted for a supply of 

 both recent and dried specimens, has found it in many of the glens 

 in the northern counties, particularly in Ballekavregan Glen (Derry), 

 and in the wild deep ravines emphatically called "The Glens" (Antrim). 

 In Scotland it was first discovered in 1841, on the banks and "in what 

 is usually called the bed of the river" Dee, in Aberdeenshire, by the 

 Rev. Mr. Brichan, to whose kindness I am also indebted for specimens. 



Its discovery caused a multiplicity of correspondence among bota- 

 nists, some maintaining that it was merely an elongate and exuberant 

 form of Equisctum variegatum ; others that it was a good species, 

 perfectly distinct from any which had been previously recorded as 

 British. The matter rested thus until the question was referred to Sir 

 W. J. [looker, and that illustrious botanist decided not only in favor 

 of its distinctness as a species, but pronounced it to be the Equisetum 

 elongatum of Willdenow, (see 'London Journal of Botany,' 42, and 

 Phytol. 174). Feeling as I do the difficulty under which I shall labour 

 in venturing to differ from so high an authority as Sir William Hook- 

 er, I must still record my opinion that the plant before me is not iden- 

 tical with the Equis. elongatum of Willdenow* and Reichenbach,t 

 the essential characters of which appear to be that it has verticillate 

 and Q-angled branches, and that the sheaths are hoary green, conco- 



* Equisetum elongatum, W. E. caulibus subduplicato-ramosis, ramis subternis 

 scabriusculis sexsulcatis, dentibus vaginarum membranaceis, W. 



E. (ramosissimum), caule striato ramosissimo, ramis virgatis striatis erectis verti- 

 cillatis, apicc floriferis. Desf. Atl. ii. p. 3982. 



Caulis tripedalis et altior quasi scandens, subduplicato raraosus, profundi striatus, 

 scabriusculus. llami tcrni, superiores simplices semipedales usque fere pedales, infe- 

 riores iterum ramosi, ramulis suboppositis sexsulcatis. Vaginje concolores dentatae, 

 dentibus albis, diaphanis, aristatis, aristis caducis. Ab omnibus mihi cognitis abunde 

 iliversum. Equisctum ramosissimum Clariss. Desfontaines non di fferre videtur. Will- 

 denow, Sp. P). V. 8. 



-j-E. elongatum, W. caule ramulisque sexangularibus longissimis superioribusspici- 

 feris, spica miicronata, vaginis concoloribus (cano-viridibus), dentibus persistentibus 

 albis vix puncto spbacelatis cartilagineis, in acumen quasi fimbriam longissimam hy- 

 alinam flaccidam deciduara productis. 



Hyemale, /3. procerum Pollin et omnino vix recedere video. 



Quadripedale et altius quasi scandens ramuli ultra pedales. Flor. Germ. Exc. 155. 



