''Asplenium surrogatum'' is a species of

fern A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes except t ...

in the family

Aspleniaceae The Aspleniaceae (spleenworts) are a family of ferns, included in the order Polypodiales. The composition and classification of the family have been subject to considerable changes. In particular, there is a narrow circumscription, Aspleniaceae ...

. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to Australia's subtropical

Lord Howe Island Lord Howe Island (; formerly Lord Howe's Island) is an irregularly crescent-shaped volcanic remnant in the Tasman Sea between Australia and New Zealand, part of the Australian state of New South Wales. It lies directly east of mainland P ...

in the

Tasman Sea The Tasman Sea (Māori: ''Te Tai-o-Rēhua'', ) is a marginal sea of the South Pacific Ocean, situated between Australia and New Zealand. It measures about across and about from north to south. The sea was named after the Dutch explorer Abe ...

. It grows both terrestrially and as an

epiphyte An epiphyte is an organism that grows on the surface of a plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphytes grow are called phoroph ...

. It occurs in forest at high elevations on the island's mountains.

Taxonomy

A global phylogeny of ''Asplenium'' published in 2020 divided the genus into eleven clades, which were given informal names pending further taxonomic study. ''A. surrogatum'' belongs to the "''Neottopteris'' clade", members of which generally have somewhat leathery leaf tissue. It forms a clade with '' A. milnei'' and '' A. pteridoides'', two other Lord Howe Island endemics, suggesting that all three species diverged after a single colonization of the island by their ancestor. This clade is sister to a large group of Pacific Ocean spleenworts.

References

surrogatum Surrogatum is a thing put in the place of another or a substitute. The Surrogatum Principle pertains to a Canadian income tax principle involving a person who suffers harm caused by another and may seek compensation for (a) loss of income, (b) expen ...

Endemic flora of Lord Howe Island Plants described in 1988 Ferns of Australia {{Polypodiales-stub