EQUISETACEiE. 167 



of the Dee, at intervals of 6 or 7 miles within the parish of Banchory- 

 Ternan, Kincardineshire, the Eev. J. M. Brichan, who says, "It 

 appears to prefer a locality where water oozing from the bank forms a 

 moist green spot, or finds its way through a rent made by the river, 

 or a channel worn by itself. The water where E. Mackaii thus fixes 

 its habitat, is generally, if not invariably, chalybeate." (Phytol. 

 1842, p. 371.) The Aberdeen botanists, however, do not seem to 

 have observed this plant, as in answer to inquiries Dr. Gr. Dickie 

 replied in Nov. 1874, " I know nothing of Equisetum trachyodon 

 in this quarter ; Mr. Roy says the same." Perhaps some form of 

 E. hyemale or E. variegatum, both of which certainly grow by the 

 Dee, may have been mistaken for E. trachyodon, but Mr. Brichan's 

 description appears to agree best with the true plant. 



Moist banks near a waterfall at the upper end of Colin Grlen, 

 Belfast, where it was found in August 1833, by Mr. J. T. Mackay, in 

 company with Mr. F. Whitla. In Ballynarrigan Glen, near Dun- 

 given, Derry, and in several glens near Glenarm, Antrim, Dr. D. 

 Moore, in Drunnan Wood, and on the adjacent shores of Loch Cullin, 

 Mayo, Mr. A. Gr. More. In two places by the side of the stream 

 in Chevy Chase, about 7 miles south-east from Grort, co. Gralway, 

 Mr. H. C. Hart. Near St. Ann's, Blarney (R. Mills), Rev. T. Allin. 



Scotland, Ireland. Perennial. Late Summer and Autumn. 



Plant erect, or more or less decumbent, 1 to 2 feet high, from the 

 thickness of a stocking-wire to that of a crow-quill. Sheaths -§- to 

 ^ inch exclusive of the teeth, which are stiff and persistent ; uppermost 

 sheath which embraces the spike funnel-shaped, gradually narrowed 

 upwards, with lanceolate teeth having broad white margins and 

 brown scabrous flexuous points. Spike about i inch long, abruptly 

 acuminated into a short mucro. 



Branches are much more frequently produced in E. trachyodon 

 than in any of the forms of E, hyemale. They may come from 

 any part of the stem, and sometimes have a secondary branch from 

 one of their internodes. In the ' Cybele Hibernica' it is stated that 

 " after a series of careful observations made in Antrim, Mr. D. Orr 

 considers that the normal state of E. trachyodon is the unbranched 

 form. In exposed situations, when broken by the wind or injured 

 by cattle, the stems throw out lateral shoots from near the point of 

 injury." (Cyb. Hib. p. 365.) 



E. trachyodon is very similar in general appearance to E. Moorei, 

 so much so that many excellent botanists appear to have mistaken 

 the one for the other, as instanced in Rabenhorst's published fasciculi. 

 In E. trachyodon, however, the ridges of the stem are not rounded on 



