(n) beautiful spreading fern of eastern North America and eastern Asia naturalized in western Europe; pinnately divided fronds show a slight tendency to fold when touched; pinnules enclose groups of sori in beadlike lobes, Syn. bead fern, Onoclea sensibilis
prop. n. A genus consisting of only species: the sensitive fern; in some classifications it is included in the Polypodiaceae. Syn. -- genus Onoclea. [ WordNet 1.5 ]