adder's tongue

Meaning

A small, primitive fern belonging to the Ophioglossaceae family, characterized by a single, undivided leaf and a separate, stalked spore-bearing structure.

Examples

• The adder's tongue is notoriously difficult to spot in the dense undergrowth due to its diminutive size.
• Ecologists monitor the population of adder's tongue in these wetlands to assess the health of the local ecosystem.