for land clearance. A less obvious threat comes from an invasive introduced tree fern species: Cyathea cooperi (the most popular garden tree fern in the United States), which has escaped from the islands' suburban gardens and now outcompetes the endemic flora. Wind-blown spores from this rapidly growing Australian import can migrate many miles into pristine Cibotium forests. This is a fairly recent phenomenon, but one which may eventually have grave consequences for the tree fern ecosystem in Hawaii. References Smith, A.R., K.M. Pryer, E. Schuettpelz, P. Korall, H. Schneider & P.G. Wolf 2006. Taxonomy 55(3): 705–731. External links Jaknouse/ferns — Genus: Cibotium Medicinal plants Fern genera