Silene vellutata delle Eolie (Silene hicesiae)

First described in 1984 ⁽²⁾, the silene vellutata delle Eolie (Silene hicesiae) is a rare flowering plant found only in the Aeolian Islands, off the coast of Sicily ^{(1) (2) (3)}.

A perennial species, the silene vellutata delle Eolie grows from a woody base, producing rosettes of hairy, elliptical leaves. The leaves have pointed tips and measure up to ten centimetres in length and three centimetres in width ^{(2) (3)}. Both fertile and non-fertile rosettes of leaves are produced, with only the fertile rosettes producing a long, erect flowering stem. The flowering stem is usually hairy and unbranched, and bears bunches of pink to purplish flowers, which grow in groups of three on short, opposite branches ^{(2) (3)}.

The flower of the silene vellutata delle Eolie is surrounded by a long, purplish calyx, which is formed from the fused sepals and measures up to 1.8 centimetres in length ^{(2) (4)}. Each flower has five petals ⁽³⁾. As in other members of the Caryophyllaceae family, the petals may be deeply notched at the tips ^{(2) (4)}.

The fruit of the silene vellutata delle Eolie is an ovoid capsule of around one centimetre in length ⁽²⁾. This splits to release numerous tiny, brown, kidney-shaped seeds ^{(2) (4)}.

Size

Height: 50 - 120 cm ⁽²⁾

For further information, please see the IUCN's Top 50 fact file on this species.

There is relatively little information available on the biology of the silene vellutata delle Eolie. It usually flowers between May and June ^{(2) (3)}, and the fruits mature between late August and the beginning of September ⁽³⁾.

Endemic to the Aeolian Islands, near Sicily, the silene vellutata delle Eolie occurs in two severely fragmented populations on the volcanic islands of Panarea and Alicudi ^{(1) (2) (3)}. The two populations are about 60 kilometres apart and occupy a total area of less than ten square kilometres ^{(1) (3)}.

A record of a third population of this species from the Palermo Mountains on Sicily has not been confirmed ⁽⁵⁾.

The silene vellutata delle Eolie grows on rocky, volcanic slopes ^{(1) (2) (3)}.

The silene vellutata delle Eolie is classified as Vulnerable (VU) on the IUCN Red List ⁽¹⁾.

The total population of the silene vellutata delle Eolie is estimated at 1,000 to 2,500 mature individuals ⁽¹⁾, with the subpopulation on Alicudi being particularly small ^{(3) (5)}. Although its populations are currently believed to be stable, both are at high risk of extinction unless urgent conservation measures are taken ^{(1) (3)}.

The main threats to the silene vellutata delle Eolie are wildfires, overgrazing by rabbits and the spread of invasive plant species, such as the tree of heaven (Ailanthus altissima). It is also threatened by inappropriate management of the protected areas in which it occurs ^{(1) (3)}. The population of the silene vellutata delle Eolie on Panarea has been found to have low genetic diversity ⁽⁶⁾.

The islands of Panarea and Alicudi are designated as nature reserves, and collection of the silene vellutata delle Eolie is strictly forbidden in both locations ^{(1) (3)}. The Aeolian Islands are also designated as a World Heritage Site, which may offer this species some protection ⁽⁷⁾. The silene vellutata delle Eolie is listed as a priority species on Annexes II and IV of the EU Habitats Directive, which covers species requiring the designation of special areas of conservation as well as those needing strict protection ⁽⁸⁾.

A number of conservation measures have been undertaken for this rare island plant. An ‘EU LIFE’ project that began in 1999 aimed to conserve four endangered plant species in the Aeolian Islands, including the silene vellutata delle Eolie. The project has included a number of actions for this species, such as improving knowledge of its biology, producing plants in cultivation to reinforce the wild population, and raising awareness of its plight among decision makers and the general public ^{(1) (3) (5)}.

In addition to these measures, the seeds of the silene vellutata delle Eolie are being collected to be grown as part of a project involving a network of Mediterranean seed banks ^{(1) (3)}. Studies are also underway into the genetic structure of this species’ populations, to provide information that will aid in its management ⁽⁶⁾.

The silene vellutata delle Eolie is part of an IUCN ‘Top 50’ plants campaign to highlight the Top 50 Mediterranean Island plants. Led by the Mediterranean Island Plant Specialist Group, this campaign aimed to provide information and raise awareness to help save plant species at high risk of extinction ⁽³⁾. Further conservation measures recommended for this threatened plant include eliminating populations of the invasive tree of heaven (Ailanthus altissima), and carrying on the conservation initiatives that were started by the EU LIFE project ^{(1) (3)}.

Find out more about the silene vellutata delle Eolie and its conservation:

• IUCN/SSC Mediterranean Islands Plant Specialist Group: The Top 50 Mediterranean Island Plants - Silene hicesiae:
  http://data.iucn.org/Themes/ssc/our_work/plants/Top50/English/pdfs/Silene_hicesiae.pdf

More information on conservation in the Mediterranean region:

• IUCN/SSC Mediterranean Islands Plant Specialist Group:
  http://data.iucn.org/themes/ssc/sgs/mipsg/index.htm
• Conservation International: Biodiversity Hotspots - Mediterranean Basin: 
  http://www.biodiversityhotspots.org/xp/hotspots/mediterranean/Pages/default.aspx
• ARKive - Mediterranean Basin:
  http://www.arkive.org/eco-regions/mediterranean-basin/

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

Calyx

All of the sepals (floral leaves) of a flower, which form the protective outer layer of a flower bud.

Endemic

A species or taxonomic group that is only found in one particular country or geographic area.

Genetic diversity

The variety of genes within a particular species, population or breed causing differences in morphology, physiology and behaviour.

Perennial

A plant that normally lives for more than two seasons. After an initial period, the plant produces flowers once a year.

Sepal

A floral leaf (collectively comprising the calyx of the flower) that forms the protective outer layer of a flower bud.

1. IUCN Red List (December, 2011)
   http://www.iucnredlist.org/
2. Brullo, S. and Signorello, P. (1984) Silene hicesiae, a new species from the Aeolian Islands. Willdenowia, 14(1): 141-144.
3. de Montmollin, B. and Strahm, W. (Eds.) (2005) The Top 50 Mediterranean Island Plants: Wild Plants at the Brink of Extinction, and What is Needed to Save Them. IUCN/SSC Mediterranean Islands Plant Specialist Group, IUCN, Gland, Switzerland and Cambridge, UK. Available at:
   http://data.iucn.org/themes/ssc/our_work/plants/t50_e.pdf
4. Heywood, V.H. (1978) Flowering Plants of the World. Oxford University Press, Oxford.
5. Troìa, A., Cardinale, M., La Manna, M., Lo Cascio, P., Pasta, S., Puglia, A.M., Quatrini, P. and Voutsinas, E. (2005) Preliminary results of EOLIFE99, a project concerning the conservation of four endangered plant species of Aeolian Archipelago (South Tyrrhenian Sea, Italy). Quaderni di Botanica Ambientale e Applicata, 16: 173-174.
6. Troìa, A. and Burgarella, C. (2004) Genetic Variability of the Endangered Island Endemic Silene hicesiae Brullo & Signorello (Caryophyllaceae): Preliminary Results. IX IOPB Meeting “Plant Evolution in Mediterranean Climate Zones”, Valencia, Spain, 16-19 May.
7. UNEP-WCMC: Isole Eolie (Aeolian Islands), Sicily, Italy (December, 2011)
   http://www.unep-wcmc.org/medialibrary/2011/06/29/33be8be5/Isole%20Eolie.pdf
8. EU Habitats Directive (December, 2011)
   http://www.jncc.gov.uk/page-1374