views updated May 21 2018

Ophioglossum (adder's tongue, snake's tongue; family Ophioglossaceae) A genus of ferns with the sterile blade(s) usually simple (rarely lobed) with reticulate veins, and the sporangia sunken along the opposite sides of a simple spike, opening by transverse slits. There are about 40 species, found in most parts of the world.