Australian tree fern is widespread in Hawaii, but is currently only known to grow in a few locations on Molokai and Lanai (see map.) This tree fern grows up to 12 m (40 ft) tall or more. Stem is covered by a cleancut OVAL SCAR PATTERN. Long WHITE and short RED-BROWN SCALES found at the base of the fronds (see this identification aid for more help). Leaves of mature plants grouped in a TIGHT ROSETTE at top of stem, rather than spread out along the stem. Sori (clusters of spores) on middle of the pinnae, or fern leaflet divisions. Found in residential areas escaping into wild areas.
Impacts: This fast growing fern, which is well-suted to shade, has wind spread spores can travel over 12 km (7 miles) from parent plant, which allows plants to be transported from the garden directly into the rainforest. Once established in the rainforest it diplaces other understory vegetation.
Dispersal Mechanism: The Australian tree fern is a common garden plant throughout Hawaii. Ferns reproduce via wind-borne spores. If you see it anywhere else on Maui, Molokai, Lanai, or the Big Island- let someone know!
Hapu'u (Cibotium chamissoi):
The native Hawaiian tree fern, Hapu'u, has BLOND to RED COLORED HAIRS along the base of the trunk and POWDERY WHITE SORI (clusters of spores) on the EDGE of the pinnae. Hapu'u is a desireable garden alternative to Australian tree fern. Be aware, though, that the trunks of hapu'u often contain a variety of invasive alien plants, like Himalayan raspberry, growing on them and these could be a source of inadvertent introduction of noxious weeds onto your island. Examine all hapu'u used and remove clinging vegetation.
Funding and support for this project was made possible by the Hawai'i Invasive Species Council, the USDA Forest Service State and Private Forestry assistance, and University of Hawai'i-Pacific Cooperative Studies Unit.