Ophioglossaceae

A single, simple, undivided or only slightly divided sterile leaf blade paired with one narrow, upright, spike- or grape-cluster-shaped fertile stalk that bears its spores directly and openly, rather than in the rolled fiddleheads or clustered sori typical of most ferns.

As true ferns this family has no flowers or seeds — its spores form directly on an upright, unfurled fertile spike rather than in the coiled fiddleheads and leaf-back sori of nearly every other fern family.

To check whether a plant belongs to Ophioglossaceae, compare the leaf arrangement, leaf type, flower symmetry, fruit type, and one distinctive marker together. A single feature can mislead; the family pattern is the combination.