Sickle Island Spleenwort

Asplenium dielfalcatum is a rare species of fern in the family Aspleniaceae, endemic to the island of Oʻahu, Hawaii. It typically grows at elevations ranging from 400 to 1,000 m (1,300 to 3,300 ft) in moist montane forests. The species is listed as Critically Endangered due to habitat loss, invasive species, and climate change.