BRITISH FERNS. 
114 
BLUNT-TOPPED HORSETAIL. 
EQU 1 SETUM UMBROSUM. 
This Horsetail has stems of three kinds. The barren 
stem has from eighteen to twenty sharp ridges, rough, 
with prominent flint particles ; its sheaths are small, 
about twenty in number. The branches are as many, 
spreading widely, and jointed. The fertile stems are 
about six inches high and have numerous joints, with 
large pale-coloured sheaths almost covering the stem ; 
the cone is oval, chestnut-coloured, the capsules white. 
The third kind of stem is of a size intermediate 
between the other two, less branched than the barren 
stem, and bearing a small cone. It is a somewhat 
rare plant, but is found in the north of England, 
Scotland, and Ireland. 
FIELD HORSETAIL. 
EQUISETUM AR VENSE. 
This is the commonest of our Horsetails, and is very 
troublesome to the farmer, being difficult to eradicate 
and noxious to cattle, probably owing to the sharp 
points of a flinty nature in which it abounds. It 
grows chiefly on sandy soil, and is an agricultural 
pest in many places. 
It is remarkable from its being the only British 
