Ophioglossidae

Ophioglossidae

[‚äf·ē·ō′gläs·ə‚dē] (botany) The adder's-tongue ferns, a small subclass of the class Polypodiopsida; the plants are homosporous and eusporangiate and are distinguished by the arrangement of the sporogenous tissue in the characteristic fertile spike of the sporophyte.