FERNS OP GREAT BRITAIN. 155 



Aberdeenshire ; as well as at Calton Glen, in Antrim ; 

 and BaUyharrigan Glen, Londonderry. 



5. E.palustre (Marsh Horse-tail). — Stem erect, with 

 numerous branches, rough; sheaths long and loose; 

 teeth long and few. This is a very common species, 

 growing often in great abundance near standing water, 

 and covering places where water has been drained, or 

 growing among the wild flowers of the bog, and 

 reminding us of Clare's lines : — 



" Here Horse-tail round the water's edge 



In bushy tufts is spread, 

 With rush and cutting leaves of sedge 



That children learn to dread; 

 Its leaves like razors, mingling there. 



Oft make the youngster turn, 

 Leaving his rushes in despair, 



A wounded hand to mourn." 



The creeping underground stem of this species is nearly 

 as large as the stem of the frond, black, and smooth, 

 and has tufts of black fibres descending from it. The 

 main stem of the frond is perfectly erect, about fifteen 

 inches high, with prominent ribs and deep furrows, 

 about eight in number, rough to the touch, though less 

 so than in some of the species, and whorled throughout, 

 except at the base, with numerous branches. The 

 joints are invested with nearly cylindrical sheaths, which, 

 being much larger than the stem, loosely clasp it, 

 some of the upper ones being nearly twice as large as 

 the stem itself. The number of marginal teeth on the 

 sheath is the same as that of the ribs on the stem. 

 They are light coloured, with black or light brown tips, 

 and membranous margins. The fertile and barren 



