Sunday 19 May
Fern (Asplenium ascensionis)
What’s the World’s Favourite Species?Find out here.
Fern fact file
- Find out more
- Print factsheet
Asplenium ascensionis is a small, dark green fern found growing on rocky walls (2). The narrow, glossy fronds are composed of smaller leaflets known as ‘pinnules’. The pinnules are short and toothed at the edges (2).
- Frond length: 25 cm (2)
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 (3).
In Asplenium ascensionis however, the sexual stage of the lifecycle does not occur and the spore-producing plant develops directly from the prothallus (3).Top
This small fern is found on Ascension Island, South Atlantic; although some experts believe this fern is actually a variety of Asplenium erectum found on the island of St Helena (2). Previously much more common, Asplenium ascensionis formed part of a carpet of ferns that constituted the main vegetation of Green Mountain in the mid-19th century (2).Top
Found in damp, sheltered ravines on parts of Green Mountain at the centre of Ascension Island (2).Top
Asplenium ascensionis is classified as Vulnerable (VU) on the IUCN Red List (1).Top
The distribution of Asplenium ascensionis populations has declined and this species no longer represents part of the ground vegetation of the island. Loss of suitable habitat and competition with introduced species such as A. capillus-veneris is likely to have played a part in its decline; although these species may be able to exist together (4).Top
Recent evidence has revealed that Asplenium ascensionis is not under as much threat as previously feared. However, long-term monitoring of the population is still being carried out by Ascension Conservation (4).Top
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:
- A small, gamete-producing structure that germinates from certain spores.
- Microscopic particles involved in both dispersal and reproduction. They comprise a single or group of unspecialised cells and do not contain an embryo, as do seeds.
IUCN Red List (August, 2012)
- Ashmole, P. & Ashmole, M. (2000) St. Helena and Ascension Island: a natural history. Anthony Nelson, England.
Australian National Herbarium (September, 2003)
- Gray, A. (2003) Red List Assessment Form. Ascension Conservation.
- IUCN Red List (August, 2012)
MyARKive offers the scrapbook feature to signed-up members, allowing you to organize your favourite ARKive images and videos and share them with friends.
Terms and Conditions of Use of Materials
Copyright in this website and materials contained on this website (Material) belongs to Wildscreen or its licensors.
Visitors to this website (End Users) are entitled to:
- view the contents of, and Material on, the website;
- download and retain copies of the Material on their personal systems in digital form in low resolution for their own personal use;
- teachers, lecturers and students may incorporate the Material in their educational material (including, but not limited to, their lesson plans, presentations, worksheets and projects) in hard copy and digital format for use within a registered educational establishment, provided that the integrity of the Material is maintained and that copyright ownership and authorship is appropriately acknowledged by the End User.
End Users shall not copy or otherwise extract, alter or manipulate Material other than as permitted in these Terms and Conditions of Use of Materials.
Additional use of flagged material
Green flagged material
Certain Material on this website (Licence 4 Material) displays a green flag next to the Material and is available for not-for-profit conservation or educational use. This material may be used by End Users, who are individuals or organisations that are in our opinion not-for-profit, for their not-for-profit conservation or not-for-profit educational purposes. Low resolution, watermarked images may be copied from this website by such End Users for such purposes. If you require high resolution or non-watermarked versions of the Material, please contact Wildscreen with details of your proposed use.
Creative commons material
Certain Material on this website has been licensed to Wildscreen under a Creative Commons Licence. These images are clearly marked with the Creative Commons buttons and may be used by End Users only in the way allowed by the specific Creative Commons Licence under which they have been submitted. Please see http://creativecommons.org for details.
Any other use
Please contact the copyright owners directly (copyright and contact details are shown for each media item) to negotiate terms and conditions for any use of Material other than those expressly permitted above. Please note that many of the contributors to ARKive are commercial operators and may request a fee for such use.
Save as permitted above, no person or organisation is permitted to incorporate any copyright material from this website into any other work or publication in any format (this includes but is not limited to: websites, Apps, CDs, DVDs, intranets, extranets, signage, digital communications or on printed materials for external or other distribution). Use of the Material for promotional, administrative or for-profit purposes is not permitted.