|March 2003. A shipment of cut flowers into Palau included ferns with sporangia and the question was, are there species of ferns with potential to invade natural ecosystems. Are there any risks?
The PIER website has the following ferns listed as potentially invasive:
- Azolla filiculoides Lam. azolla, Large mosquito fern
- Azolla pinnata R. Br. Mosquito fern, Ferny azolla, Water velvet
- Cyathea [Sphaeropteris] cooperi (Hook. ex F. Muell.) Domin – Australian tree fern
- Platycerium bifurcatum (Cav.) C. Chr. Elkhorn fern, Staghorn fern
- Salvinia molesta D. Mitch Salvinia, Water fern, Kariba weed, Africanpayal
- Centaurium [Gentiana] spicatum (L.), Fernald spiked centaury
- Lygodium palmatum (Bernh.) Sw. Hartford fern, American climbingfern, Creeping fern, Windsor fern
See also The Global Compendium of Weeds: www.hear.org/gcw/pdfs/gcw_intro.pdf
The experience in Hawaii with Salvinia is worth noting: It is an aquatic weed and can be a serious problem. At the time (2003), Hawaii was in the midst of cleaning the weed from a 300 acre freshwater lake, 90% of which was choking with the weed. It has taken many staff-hours, heavy equipment, and lots of herbicide to clear it. So far, about a 1/4 of the lake has been cleared, with much work remaining. The correspondent had not seen anything like it during his 30 years working for the Hawaii Department of Agriculture.