Whatever their form, fungi are a vital part of the diversity of wildlife in all habitats and they play a vital role in recycling nutrients. Of particular value is their ability to rot timber - without them our woodlands would be cluttered with fallen branches and tree trunks, locking up nutrients. It is because of their importance that English Nature is currently sponsoring a Biodiversity Action Plan to preserve 40 species of fungi which are particularly valuable and at risk.

Amongst the species are some rare woodland fungi - the hedgehog fungus (Hericium erinaceum) and its close relatives Hericium coralloides and H. cirrhatum together with the Oak polypore (Piptopterus pulvinus). All species of Hericium were at one time put in the genus Hydnum. All these species are protected under the Wildlife and Countryside Act 1981 and therefore must not be touched and under no circumstances picked, even though some of them are quite edible. If by chance they are found, whether in Chorley or anywhere else in Great Britain, the best thing to do is to telephone Carl Borges who is the contact man for English Nature's Biodiversity Action Plan for fungi. His number is 01206 796666, but he is frequently, not unexpectedly, out in the field and you may well have to leave a message with one of his colleagues. If he is going to be out in the field for several days, they will pass on his mobile telephone number if you have serious news of a new find for him.

The three species of Hericium vary in form. They are all a white or ivory colour but H. erinaceum is a solid mass of upto 4 cm in length forming what I think looks much more like brain tissue than a hedgehog, despite its name. The other two are much more branched and look a little like a miniature cauliflower with "teeth" or "spines" on the lower surface. These are covered with the spore forming layer. The spines range in length from 0.5 to 1.5 cm. H. erinaceum and H. coralloides prefer beech, the former most often on tree trunks and the latter on rotten logs and branches. However, H. coralloides is also found on fir and is by far the largest as the coral-like or cauliflower-like tufts can be as much as half a metre across. H. cirrhatum has a fairly catholic taste in trees, where it is found on trunks growing without a stalk as a rather fleshy fungus, tinged pale yellow or reddish and up to a maximum of 10 cm across.

The Oak Polypore (Piptoporus pulvinus) - though its scientific name is in dispute and it may well change when the taxonomists finally conclude their arguments - is an annual polypore, not long lived and best looked for between June and the beginning of September, growing in old open woodlands on mature Oaks or on the fallen trunks of old Oaks. It can live on standing trees from just above ground level to a height of 12 metres. It is not dissimilar in appearance to Birch polypore (Polyporus betulinus) but starts off life as a white or cream colour and darkens with age with a yellowish tinge. The mushroom's fruiting bodies are flat with a smooth, rounded edge and a maximum width of about 19 - 20 cm. They can grow singly, in layers or in clusters.