Asplenium unisorum

Asplenium unisorum, the singlesorus island spleenwort,^[5] is a species of fern endemic to the Hawaiian Islands.^[1] It only lives between 650 and 700 m (2,130 and 2,300 ft) in the Waiʻanae Range on the island of Oʻahu.^[1] It is classified as critically endangered, with a fragmented, actively shrinking mature population of around 1,150.^[1]

Asplenium unisorum
Conservation status
Critically Endangered  (IUCN 3.1)[1]
Endangered (ESA)[2][3]
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Division:	Polypodiophyta
Class:	Polypodiopsida
Order:	Polypodiales
Suborder:	Aspleniineae
Family:	Aspleniaceae
Genus:	Asplenium
Species:	A. unisorum
Binomial name
Asplenium unisorum (Wagner) Viane[4]
Synonyms[4]
Diellia unisora Wagner

Description

It grows 5–30 mm (0.2–1.2 in) tall, with a 5–10 mm (0.2–0.4 in) diameter.^[6] Leaf stalks branch off the main stem, which also features a few "small black scales".^[6] The stalks themselves are "black and shiny", around 2–5 cm (0.8–2.0 in) long.^[6] Branching off from the stalks, the fronds of the fern are 8–30 cm (3.1–11.8 in) tall by 0.5–3 cm (0.2–1.2 in) broad.^[6]