74 HANDY BOOK OF 
H. LUCENS. 
The Marsh-fern or Lastraa thelypteris ; Polypodium 
thelypteris of Withering, Lightfoot, Berkenhout, and Hud- 
son, and bearing at least four names assigned by botanists, 
is one of our rarest and most local species. It abounds in 
wet and marshy grounds, and moist woods and bogs, where 
its black, slender, and wiry rhizoma often creeps to a wide 
extent. The roots are also dark, fibrous, and, in some in- 
stances, very long ; they frequently penetrate to a con- 
siderable depth, while the rhizoma spreads widely and 
horizontally. 
This local species is unknown in Wales and Scotland, and 
in Ireland is generally believed to be restricted to the county 
of Antrim, near the north-east coast of Lough Neagh. 
" On Lough Neagh's banks, where the fisherman strays, 
When the clear cold eve's declining, 
And sees the round tower of other days 
In the stream heneath him shining." 
Throughout England, the localities of the Marsh-fern are 
widely spread, but universally of a moist and humid cha- 
racter. Learmouth Bogs, in Northumberland, are con- 
sequently its favourite resort ; as also marshy places 
in Cheshire; Whittlesea Mere, Cambridgeshire; Filsby, 
Ormsby, Bolton Bay, Horning Marshes, Kent; Norfolk; 
