Ferns of Pitcairn

Pitcairn Island has a fern flora of around 30 species, all of which are similar to or only doubtfully distinct from those of the Society and Austral Islands. It is presumed that these species which have succeeded in colonising the most south-easterly extension of Polynesia are among the most successful in dispersal of the Malayan-Polynesian ferns.

This stamp issue focuses on four ferns, two of which are endemic to Pitcairn:

20c - Dicranopteris linearis is a common species of fern known by many common names, including Old World forked fern. Spreading along the ground via cloning and climbing on other vegetation, it can also reproduce via spores. The stem grows from the rhizome, branches at a 45° angle, and forms fronds that continue to bud and branch. In this way the growth can continue for a long distance as the plant forms a mat, grows over itself in layers, and spreads. When climbing, the leafy branches can reach over 6m long and can climb 10m high when supported by a tree. The leaves are linear in shape, up to 7 cm long, a few mm wide and the undersides are hairy and sometimes waxy. The fern grows easily on poorly drained, nutrient-poor soils and particularly in disturbed habitats and steep slopes. It does not tolerate shade, so once established it will eventually be shaded out by taller vegetation unless it climbs above it, or continued disturbance limits tree establishment. It may suppress the growth of new stands of trees, especially when it becomes a dense thicket. Where the fern is eliminated, invasive species of plants such as Roseapple can move in, so one important function of the fern on Pitcairn is to prevent these plants from encroaching. Stabilising eroding slopes is also a quality of this fern.

$1.00 - Loxoscaphe gibberosum is found in the Pacific region from Fiji to Pitcairn, but is absent from Samoa. On Pitcairn it is a moderately sized, graceful fern which is common and found in shaded areas, on rock faces and rocky woodland floors. In the same species as Asplenium gibberosum (incidentally a fern used in Fiji for medicinal purposes), L.Gibberosum is a beautiful fern and soft in appearance. However there is little information documented about it.

$3. Ferns of Pitcairn mini sheet

00 – Ctenitis cumingii is endemic to Pitcairn, and occurs in a highly restricted range. Named after the English collector Hugh Cuming, this fern grows in native woodlands at moderate to high altitudes on Pitcairn, though related species grow elsewhere in Polynesia. The fronds are soft textured, and the frond stem base is characteristically covered in long brown scales.

$3.40 - Angiopteris chauliodonta known locally as “Nehe”, is also endemic to Pitcairn and has only six populations with a total of 774 plants (of which only 147 are mature adults). It has an IUCN listed status as endangered but it is considered that this status should be revised to critically endangered. On Pitcairn there is good evidence of regeneration in several populations, however, many of the newly formed plants at Brown's Water are on steep unstable slopes and it is questionable whether they will survive to maturity This giant terrestrial fern is an imposing and attractive species, with fronds up to 4m long. It is located in native fern-rich forest that is, in many areas, heavily invaded by Rose Apple Syzygium jambos and Wild Sage Lantana camara. In 1997 a new population was established in Jack Willem’s valley, close to Adamstown.

The main threats to the Pitcairn flora include critically small population size, highly restricted range, erosion, lack of seed dispersal agents, and invasion by exotic species. The latter is the main threat to the native flora. The flora distribution data available for Pitcairn is now probably more complete than for most other Pacific islands, and it has facilitated the development of conservation priorities.
Conservation management especially for endemic species, will be through reinforcement of existing populations to maximise their genetic diversity and the moving of new populations to suitable habitats. Several protected areas have been suggested on Pitcairn, including areas of high local biodiversity (e.g. Brown's Water), good remaining native forest habitat (Faute Valley, upper McCoy's Valley), a forestry and timber reserve (St Pauls), cultural reserves (Tautama) and provision of a reserve with guided trails (The Hollow/Garnet's Ridge). If these areas can be adequately protected, they would conserve most of the vascular plant diversity and forest resources on Pitcairn.

Ferns of Pitcairn
Please Note: All prices are in New Zealand Dollars

Set of 4 stamps		$7.60
Miniature sheet with 2 stamps		$6.40
First Day Cover with stamp set		$9.10
First Day Cover with miniature sheet		$7.90

Technical Details

Designer:	Sue Wickison, Wellington, New Zealand	Pitcairn Stamps proudly brought to you by:
Printer:	Southern Colour Print, Dunedin, New Zealand
Process:	Offset Litho
Stamp size:	50mm x 27.14mm vertical
Format:	Four vertical stamps and one die-cut miniature sheet with two stamps
Perforation Gauge:	14.583 x 14.00
Denominations:	$0.20, $1.00, $3.00 and $3.40
Paper:	103gsm Tullis Russell Yellow/Green phosphor stamp paper
Period of Sale:	19 October 2016 for a period of two years

Acknowledgement: The Philatelic Bureau wishes to thanks Steve Waldren, Ireland; Michael Fay, USA and Carol Warren, Pitcairn Island, for their valuable assistance.