any of numerous flowerless and seedless vascular plants having true roots from a rhizome and fronds that uncurl upward; reproduce by spores
source: WordNet 3.0
An order of cryptogamous plants, the Filices, which have their fructification on the back of the fronds or leaves. They are usually found in humid soil, sometimes grow epiphytically on trees, and in tropical climates often attain a gigantic size.
