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THE BRITISH HORSETAILS. 
This race of plants bears an aspect altogether different 
from that of the groups in whose company they are placed 
in books ; and indeed they have no very obvious affinity 
to any existing order of plants. In their mode of growth 
they have a certain resemblance to two small groups of 
plants, the Ephedras and Casuarinas, but this resem- 
blance is confined to their general aspect, and is in great 
measure owing to the peculiar jointing of the stems and 
branches. With Ferns and Club-mosses they have little 
in common, though so frequently associated with them in 
books. Their most direct relationship is probably with a 
small group called Liverworts (Marchantiacew), and the 
aquatic group Gharacece, 
The Horsetails are distinguished from other plants by 
the following characteristics. They are leafless, branching 
plants, with fistular jointed stems, separable at the joints, 
where they are solid, and at these points surrounded by 
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