THE WOOD FERNS. 149 



though subjected to great cold for a 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 Aspidium, the free-veined species 

 (which include our wood ferns) to that of Nephrodium 

 and those in which the veins connect at the tips to 

 Lastrea ; though this latter name is really synonymous 

 with Nephrodium. The word Nephrodium is from the 

 Greek and is in allusion to the reniform indusia. 



