New Forest parmelia  (Parmelia minarum)

Classified as Vulnerable in Great Britain (3) and is protected by Schedule 8 of the Wildlife and Countryside Act 1981 (4).

The New Forest parmelia is a 'foliose' lichen (3), this means that it has a leaf-like structure, comprising of thin lobes (5). The lobes are greyish-white in colour and have a somewhat glossy upper surface with mats of outgrowths called 'isidia' that are tipped with brown (3).

In the UK, this species occurs only in southern England, in the New Forest in Hampshire, West Cornwall, Dorset and Devon (6). Elsewhere it is known from south-west Europe, south-east USA, Brazil, Central America, India, eastern and southern Africa, south-east Asia and Japan (3).

In Cornwall this lichen grows on coastal rocks and trees, and on one turkey oak in a valley. In the New Forest it is known to occur on acid bark of old beech trees in ancient woodland habitat. It shows a preference for sheltered locations that are well lit, often at the edges of glades (4).

Lichens are remarkable organisms; they are stable combinations of an alga and/ or a cyanobacterium with a fungus, living together in a symbiotic association(7). The fungus causes the alga to release sugars, which allow the fungus to grow, reproduce and generally survive. The fungus provides protection for the alga, and enables it to live in environments in which it could not survive without the fungal partner (7). A general rule is that the fungal component of a lichen is unable to live independently, but the alga may live without the fungus as a distinct species (4). Many lichens are known to be very sensitive to environmental pollution, and they have been used as 'indicators' of pollution (5). Much confusion has occurred between the New Forest parmelia and the related lichen, Parmelia horrescens (3).

One identified threat is shading by regenerating holly plants in the New Forest (4). Other potential threats include tree felling and fire (6).

Many of the sites that support this species are Sites of Special Scientific Interest (SSSIs). This lichen is not a UK Biodiversity Action Plan Priority Species, but has a Local Species Action Plan in Cornwall, which aims to maintain and enhance the current populations (6). The New Forest populations have been monitored and assessed, and it has been suggested that the Cornish populations are be similarly investigated (4).

For more on this species see the Local Biodiversity Action Plan Species Action Plan for Cornwall, available on-line at:
http://www.wildlifetrust.org.uk/cornwall/wow/audit2/action_3.htm
For more on British Lichens see: Dobson, F. (2000) Lichens: An illustrated guide to the British species. The Richmond Publishing Co. Ltd., Slough.