(Science: botany) 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.
The plants are asexual, and bear clustered sporangia, containing minute spores, which germinate and form prothalli, on which are borne the true organs of reproduction. The brake or bracken, the maidenhair, and the polypody are all well known ferns. Christmas fern. See christmas.