EQXTISETUM. 
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are attached. These, on bursting, disperse a great number 
of greenish spores. 
This species grows naturally in moist shady woods ; and 
though local, owing apparently to the conditions necessary 
to its growth, namely, shade and moisture combined in a 
peculiar way, it is, nevertheless, a widely-distributed plant ; 
and can hardly be considered as uncommon throughout 
the United Kingdom. Its fertile stems are in perfection 
about the middle of April, and its barren stems in June. 
Equisetum limosum, Linnwm, 
The Water Horsetail, or Smooth Naked Horsetail. 
This is a common species and generally distributed, 
occurring principally in pools, ditches, and marshy places, 
though occasionally in running streams. It is rather a 
tall-growing plant, the stems rising from two to three feet 
or more in height, springing from the joints of the dark- 
brown underground stems, which also produce whorls of 
black fibrous roots. The stems are, though finely ribbed, 
very smooth to the touch, the furrows being very shallow ; 
their smoothness no doubt arising from the presence of a 
very slight coating of the siliceous particles, which, when 
more abundant, give their peculiar harshness to some of 
