Marattia howeana

Marattia howeana (W.R.B.Oliv.) P.S.Green, a rare endemic to Lord Howe Island with only a few known remaining populations. Several marattioid fern species, including M. howeana and the Hawaiian endemic M. douglasii (C. Presl) Baker, are seriously threatened by introduced feral pigs who favor the sweet fleshy rhizome as a food source. The fully fused synangia (fused sporangia, ca. 3–5 mm in length), characteristic of Marattia s.l., are captured in this photo just at the stage of dehiscence. This photo was taken from live material grown at Humboldt State University, Arcata, California, where new methods for efficient asexual propagation of marattioid ferns are currently under development.