fern - any of numerous flowerless and seedless vascular plants having true roots from a rhizome and fronds that uncurl upward; reproduce by spores

genus Ophioglossum, Ophioglossum - the type genus of the fern family Ophioglossaceae

Ophioglossum pendulum, ribbon fern - epiphytic fern with straplike usually twisted fronds of tropical Asia and Polynesia and America