FELICES 
BRITANNIC^. 
63 
twenty joints; five or fix of which joints are deftitute of fecond leaves, 
but are, as well as the reft, furrounded each with a vagina, not inflated 
as in the fertile jfhoot, but clofely embracing the ftem ; they are of a 
pale-green colour, and each is divided in about twelve black acute points 
at the margin. 
The fecond leaves grow from the bafe of the vaginae, at the joints of 
the firft leaf; each has a pale-coloured, pellucid, quadridentate, proper 
vagina, at its bafe ; each confifts of eight or ten joints, quadrangular, 
with quadridentate vaginae at each joint. In the fpecimen before me, the 
firft leaf confifts of fixteen joints, five of which, from the root, produce 
no fecond leaves; at the fixth the leaves are fliorter than at the feventh, 
and grow gradually a little longer upwards to the tenth, from whence 
they diminifh to the top, where they are fhorteft. 
The barren leaves in this plant fo nearly refemble thofe of the 
Equifetum paluftre, in fome ftages, that they are not eafily diftinguifhed 
at firft fight; but may at all times be known by this remark, That the 
fecond leaves in the arvenfe are quadrangular, and the vaginas quadriden¬ 
tate ; but in the paluftre they are pentangular and quinquidentate. 
The fertile fhoots of this fpecies cannot be diftinguifhed from thofe 
of the Equifetum fylvaticum, before the fecond leaves appear, except by 
the number of lafcinas into which the vaginae are divided, in the firft 
being twelve, in the laft three or four. 
It grows in fliady moift places about woods and rivulets, and flowers 
in April. 
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E Qja I S E T U xM 
