THE WOOD FERNS. 149 
though subjected to great cold fora large part of the 
year, its fronds are evergreen. The illustrations are 
from Vermont specimens. 
The derivation of the names Aspidium and Dryopteris 
will be found in the chapter devoted to the marsh fern 
tribe. The name Lastrea by which this genus is com- 
monly known in Great Britain was given in honour of De 
Lastre a French botanist. As the wood ferns are now 
grouped there are several well-marked tribes and it is 
likely that each will ultimately be recognised as a sep- 
arate genus. In this case certain exotic species with 
anastomosing veins and circular, peltate indusia will be 
entitled to the name of Aspzdium, the free-veined species 
(which include our wood ferns) to that of Mephrodium 
and those in which the veins connect at the tips to 
Lastrea; though this latter name is really synonymous 
with Mephrodium. The word Nephrodium is from the 
Greek and is in allusion to the reniform indusia. 
