Three endemic species dominate the tall and lower montane forests of the archipelago, "Drimys confertifolia" on both main islands, "Myrceugenia fernandeziana" on Robinson Crusoe, and "M. schulzii" on Alexander Selkirk. Endemic tree fern species of southern hemisphere genus "Dicksonia" ("D. berteroana" on Robinson Crusoe and "D. externa" on Alexander Selkirk) and the endemic genus "Thyrsopteris" "(T. elegans)" are the predominant species in the tree-fern forests. An endemic species of sandalwood, "Santalum fernandezianum", was overexploited for its fragrant wood, has not been seen since 1908, and is believed extinct. The Chonta palm ("Juania australis") is endangered.