VARIEGATED HORSETAIL. 117 



Yariegated Horsetail (Equisetum variegatwri). 



A small and local species closely allied to the Dutch Rush, 

 and growing in swampy ground and ditches. The barren and 

 fertile stems are similar, without the whorled branches from the 

 joints, though occasionally a solitary branch will be produced 

 here and there. But the stems fork a good deal just below the 

 ground, so that they form small tufts. They are very slender, 

 rough, with about ten prominent ridges and intervening furrows ;, 

 usually about a foot high or less, but sometimes as much as 

 two feet. The short sheaths, which fit rather closely, are wider 

 above than below. It is the colouring of these that gives 

 the plant its name, for whilst the lower half is pale green like 

 the stem, the upper half with the teeth is black, but these have 

 white margins of thin material and show up plainly against the 

 green of the next joint. The cone, which is small, is egg-shaped, 

 rather sharply pointed, and ripe in July and August. (Plate 126.) 



The stem in cross-section is almost identical with that of the 

 Dutch Rush, of which this may be a sub-species. There are 

 several recognized varieties, of which var. -wilsoni is a large 

 form with smoother, more erect stems two to three feet in height, 

 and having short blunt teeth to the sheath. Var. aretiarium 

 has more slender, leaning stems, and the teeth of the sheath 

 are wedge-shaped. Var. trachyodon has stouter erect or leaning 

 stems, from one to three feet in length. Sheaths not enlarged 

 above, at first pale green with black band below the teeth, but 

 finally wholly black. 



As already indicated, the Variegated Horsetail is of only local 

 occurrence, and that chiefly from Yorkshire northward to the 

 Clyde and Ross-shire ; but from Yorkshire it continues south- 

 ward through Cheshire and Wales ; it occurs again in counties 

 so remote as Norfolk and Devonshire, as also in Ireland. The 

 var. arenarium affects sandy sea-shores, but is not found farther 



