GENUS XIX. 
OPEIOGLOSSUM, Liiuunts. 
ADDER'S TOXGCK. 
GEX. CHAR. Fructification naked arranged in two lines 
along the margin of a contracted frond forming a com- 
pact flattened simple spike. Spore-cases sessile connate, 
leathery, without reticulations, two-valved opening trans- 
versely. Frondi two-branched. Veins uniform, reticu- 
lated, forming elongated meshes. 
The name is derived from ophios a serpent, and glossa 
a tongue ; the fertile branch of the fronds having some 
resemblance to an adder's tongue. 
1. Ophioglossum vulgatum, Liwueut Common 
Adder's Tongue. Fronds solitary ; barren branch ovate- 
obtuse. 
OPHIOGLOSSCM virusx-mc, Linnsus : 8m. Eng. Ft iv., 316. Engr. 
Bot. 108 : Bab. Man. 417 : Hook, and Am. FL 578 : Florigr- Brit, 
ir., 33 : Xewm. 349 : Franc. 6. 
The Common Adder's tongue has the habit of the 
Moonwort, but a different structure. Like it, too, it is 
folded straight in vernation, hi which respect these two 
plants differ from all other British ferns. The caudex Ls 
represented by a central crown, which produces a few coarse 
brittle fleshy roots, some of which extend horizontally 
