Ihiihi Fern
This is the Ihiihi Fern. It looks a lot like a four-leafed clover but it really is a fern. It is terribly rare because of its general habitat loss. Invasive grasses almost always dominate and out compete this little fern. Highly endangered, there are only small populations of this fern on Oahu, Moloka`i, and Niihau.
(Better close-up pictures not taken by me here)
http://www.hear.org/starr/hiplants/images/thumbnails/html/marsilea_villosa.htm
This past Saturday (March 8, 2008), the Oahu Invasive Species Committee, a bunch of volunteers, and a group of boy scouts joined up to clear the habitat for this fern and build a fire break. The hot Hawaiian sun beat down heavily but we were able to accomplish a lot of work. Hopefully we did more good than bad. I know I accidentally pulled a fern or two up while trying to weed out the invasives.
I am somewhat disappointed at myself that I didn't get a good close-up picture of them when I had the chance. I guess I'll just have to hike up there again some time in the future.
There are more pictures of the service-trip/hike here:
http://s237.photobucket.com/albums/ff153/pueo77/OISC%203-8-08/?albumview=grid
There are some good landscape pictures of Hanauma Bay, Koko head, and Hawaii Kai in there so I'll eventually post them up here... but if you want to see the photos now, give it a look.