Fen orchid (Liparis loeselii)
|Size||Height: 6 - 20 cm|
Listed under Annexes II(b) and IV(b) of the EC Habitats Directive, Schedule 4 of the Conservation (Natural Habitats, etc.) Regulations 1994 and Schedule 8 of the Wildlife and Countryside Act, 1981.
This rare orchid appears initially as a green scaly-looking bulb amongst the wet moss of a fen or a dune slack. There are two closely related varieties of this plant, although some authorities seem to be questioning this. They both usually have two leaves on opposite sides of the stem, emerging from the base. The East Anglian subspecies has leaves that are spear-shaped, pointed at the ends and rather shiny and greasy-looking. The Welsh variety (var. ovata) has blunter, more elliptical leaves and is a shorter plant generally. The flowers are grouped rather loosely at the top of the stem and are a yellow-green in colour. The flower 'spike' makes up the top 2-10 cm of the height of the plant. The Welsh variety usually has a shorter flower spike. The specific name loeselii commemorates Johann Loesel, a seventeenth century Prussian botanist.
This species was once known from more than 30 separate sites but, today, is thought to survive at just four sites. Two of these are in the Norfolk Broads in East Anglia, whilst the variety ovata is found on two dune systems in South Wales and, until fairly recently, was also found in North Devon. This orchid is also found across much of central Europe where it is rare but described as 'locally common'.
The two sub-species require different habitats, the East Anglian variety favouring mossy calcareous fens, while the Welsh variety prefers wet dune slacks.
Fen orchid flowers throughout the months of June and July, and the fen variety is believed to prefer areas where peat cutting is taking place. The orchid colonises the bare fen surface as an 'early successional' species, taking advantage of a new habitat. Where it occurs on its Broadland site, it can appear quite numerous, and 242 plants were found in 1996.
The chief threats to this species are loss of habitat through drainage and pollution, and the abstraction of groundwater for irrigation of crops. The orchid may also have declined through a cessation of peat digging, which provided suitable conditions for new colonies to form.
Fen orchid is listed in the UK Biodiversity Action Plans (UK BAP), and is included in English Nature's Species Recovery Programme (SRP). All the populations of the plant are within National Nature Reserves (NNRs), which are also protected as Sites of Special Scientific Interest (SSSIs). The Welsh sites are the subjects of a major management project for the species, co-ordinated by the Countryside Council for Wales (CCW). The Norfolk Wildlife Trust, the lead partner for this species in England, have produced a management plan to conserve the orchid. This includes the possibility of re-introducing it on to suitable sites within its known former range.
Information supplied by English Nature.
- Calcareous: containing free calcium carbonate, chalky.
- Colonise: establish a colony (group of organisms living together).
- Colony: a group of organisms living together, individuals in the group are not physiologically connected and may not be related, such as a colony of birds. Another meaning refers to organisms, such as bryozoans, which are composed of numerous genetically identical modules (also referred to as zooids or 'individuals'), which are produced by budding and remain physiologically connected.
- Dune slack: depressions between sand dunes that are often wet during the winter.
- Subspecies: a different race of a species, which is geographically separated from other populations of that species.