| Kingdom | Plantae |
|---|---|
| Phylum | Pteridophyta |
| Class | Filiopsida |
| Order | Pteridales |
| Family | Pteridaceae |
| Genus | Pteris (1) |
| Size | Height: up to 1 m (2) |
Pteris adscensionis is classified as Critically Endangered (CR) on the IUCN Red List (1).
Cricket Valley is situated on the central mountain of Ascension Island (known as Green Mountain) at a height of 460 metres above sea level (3).
Ferns are ‘primitive’ plants that spread by releasing spores rather than by producing flowers and fruits. The distinctive frond stage of the fern lifecycle is asexual; spores are released from the fronds, which then germinate into minuscule heart-shaped structures known as ‘prothalli’. It is here that the sexual stage of the lifecycle occurs; male and female organs on the prothallus produce sperm and eggs respectively. If the female eggs are fertilised successfully, a new fern plant will begin to grow and the cycle starts again (4).
In Pteris adscensionis however, the sexual stage of the lifecycle does not occur and the spore-producing plant develops directly from the prothallus (4).
Pteris adscensionis once constituted an important component of the vegetation of Ascension Island; this species has undergone a dramatic decline however, and is now absent from the summit of Green Mountain. Competition with introduced species is likely to be responsible for this decline (2). Today, populations are extremely reduced and Pteris adscensionis is thought to be the most threatened of Ascension’s flora, with less than 200 plants remaining in the wild (3).
Ascension Conservation is carrying out vital cultivation of this species and is monitoring the highly vulnerable wild population (3).
This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk
New images of the rough-toothed dolphin. More
© Richard White
Richard White
Ascension Island Conservation Officer
Conservation Centre
Georgetown
Ascension Island
ASCN IZZ
South Atlantic Ocean
conservation@atlantis.co.ac
Embed this ARKive thumbnail link by copying and pasting the code below.
Terms of Use - The displayed thumbnail may be used as a link from your website to ARKive's online content for not-for-profit private, scientific, conservation or educational purposes only. Portlets may NOT be used within Apps.

MyARKive offers the scrapbook feature to signed-up members, allowing you to organize your favourite ARKive images and videos and share them with friends.