( 346 ) 
at the joints, which leaves fland in 
whirls gradually diminifhing to the top. 
If you fhake a little of the duft from 
the fpike on a fheet of white paper, and 
examine it with a good glafs, you will 
fee it ikip, as if it were alive. There 
are of this genus feven fpecies, fix of 
which have been found in this king- 
dom. In the Flora Londinenfis you will 
fee a good print of the Equifetum ar- 
venfe, 
Opbioglo/um. Of this genus there are nine 
fpecies, but one of which has been 
found -in Britain : it is the O. vutgatum, 
common Adder's Tongue. Its generic 
character is Spica artlculata^ dijlicha-, 
articulis tranfuerfim dehifcentibus. It is 
a fingle, thick, oval, leaf, without rib 
or veins, on a foot-ltalk four inches 
long. 
Ofmunda. Of thefe the fpike is branched, 
and the capfules globular. There are 
four fpecies in this kingdom. One of 
them is the O.fpicans, you will find it 
in Curtis. We call it Rough Spleenwort. 
The feeds are only on the center-leaves, 
which are more erect and the wings 
more diftinft. 
Acrof- 
