138 HISTORY OF BRITISH FERNS. 



Botrychium, most obviously, in its parts being all simple, 

 while those of Botrychium are compound. Its habit of 

 growth is precisely the same, but the fructification is very 

 different, consisting of a distichous spike of imbedded spore- 

 cases. There is but one native species. 



The name Opliwglossum literally means Adders-tongue, 

 which is the English name borne by this plant. It is 

 derived from the Greek ophios, a serpent, and glossa, a 

 tongue ; and is applied in consequence of the resemblance 

 of the fertile fronds to the tongue of a serpent. 



OPHIOGLOSSUM VULGATUM, Linnaus. The Common 

 Adders-tongue. (Plate XVIII. fig. 3.) 



A small stemless plant, producing a few coarse brittle 

 roots from a central crown which represents the stem, and 

 which annually produces a bud from which the new frond 

 arises. The young fronds are produced about May, and 

 perish by the end of the summer. They grow from three 

 inches to ten or twelve inches in height, with a smooth, 

 round, hollow, succulent stipes of variable length. In the 

 upper part this becomes divided into two branches, the one 

 branch leafy, entire, smooth, ovate-obtuse, traversed by 

 irregularly anastomosing veins, forming elongated meshes. 



The fertile branch is erect, contracted, about half its 



