48 RATTLESNAKE FERN AND ADDER’S-TONGUE. 
In America the adder’s-tongue is found from Canada 
to Florida, Missouri and sparingly to California. In the 
Old World it occurs in Europe, Asia, Africa and Aus- 
tralia. Considering its wide distribution, some difference 
in specimens from remote points may be expected. In 
the western part of our range, there is a form named 
LEngelmannt. It may be distinguished from the type by 
the slender stipe and apiculate sterile portion with 
broad areolae and anastomosing veins. It is found as 
far east as Virginia. This also is probably a form of 
vulgatum and better characterised as O. vulgatum Engel. , 
manit, 
The common name of adder’s-tongue is much older 
than the scientific Ophioglossum and both have the same 
meaning. Adder’s-spear, adder’s-spit and other names 
formerly in use, all refer to a fancied resemblance be- 
tween the plant and the adder. The fronds were long 
used as the principal ingredient in “adder’s-spear oint- 
ment ” to make which they were boiled with unsalted 
butter. Drayton alludes to its use in the lines 
“For them that are with newts, or snakes or adders stung 
He seeketh out a herb that’s called adder’s-tongue, 
As Nature it ordained its own like hurts to cure, 
And sportive, did herself to niceties inure.” 
There are about twenty species of Ophioglossum known. 
In northeastern America, there is but a single species 
unless the two forms noted should prove distinct. Three 
other species are sometimes found in tropical parts of 
the United States. 
