FERNS OP GREAT BRITAIN. 159 



nature than the fertile ones, are taller and more slender, 

 and bear more branches; their sheaths, too, though 

 similar, are smaller, and fit the stem more closely, and 

 their ribs are more strongly marked. The compound 

 branches are often crowded on the stem, the side 

 branches being about four inches long, and bearing at 

 every joint a whorl of branches about half that length. 

 Sometimes these are again branched, and drooping down 

 in whorl beyond whorl, the frond becomes exceedingly 

 elegant, narrowing upwards to a slender point, which 

 droops too with the weight of depending branchlets. 

 The terminal branches are 3-ribbed, and somewhat 

 triangular in form^ and each joint is terminated by three 

 long pointed teeth of the same colour as itself. 



7. JE. umbromm (Shady Horse-tail, or Blunt-topped 

 Horse-tail). — Barren stem very rough, particularly above, 

 branches simple ; fertile stem either unbranched, or with 

 simple branches and larger sheaths. This species has 

 not hitherto been found in many places in this kingdom, 

 though it occurs in some parts of Yorkshire, and about 

 the Westmoreland Lakes; at Wynch Bridge, Teesdale, 

 Durham; near Warkworth, in Northumberlannd ; near 

 Mere Clough, Manchester ; as well as in several Scottish 

 habitats ; and in the mountain glens of Antrim, in 

 Ireland. It was first discovered in the latter locality 

 by Mr. T. Drummond, and hence this plant was for- 

 merly termed E. Drummondii, but it has since been 

 ascertained to be the species called by Willdenow, 

 E. umbrdsum. It seems probable that this Horse-tail 

 will be found to be plentiful in woods in the north of 

 this kingdom. 



