Phymatosorus scolopendria commonly called monarch fern, musk fern, maile-scented fern, lauaʻe or wart fern is a species of fern within the Polypodiaceae family. This fern grows in the wild in the Western Pacific rim from Australia to New Caledonia to Fiji and throughout the South Pacific to French Polynesia. It was introduced in Hawaii in the late 1910s and has subsequently naturalized rapidly. It is found on all main islands. Its Hawaiian name is Lauaʻe. The scientific name P. scolopendria has been misapplied to Microsorum grossum.