TRIP REPORT : Fungal Foray, Catchpool, Rimutaka Forest Park

 Saturday :   7 May 2005

Geoff Ridley describing features of Tylopilus formosus. Photo: Ian Goodwin.

Spurred on by the damp conditions, a party of enthusiasts assembled at the Catchpool carpark, intending to amble along the Orongorongo Track in search of mushrooms and other fungi.   This was not to be, as the storm at the end of March had turned it from an amblers’ track to a real one, a fact reinforced when we had to ford the river to get out of the carpark.   Slow progress was made largely owing to the number of fungi found and as a result a twenty minute stroll around the Loop Track took five hours.

The first fungus encountered was growing on the wood mulch in the carpark plantings.   This was the orange capped Stropharia, usually called by the European name S. aurantiaca.   It is now believed to be an Australian species Psilocybe ceres.   Once across the river and into the native forest there are essentially two types of communities; the broadleaf podocarp forest dominated by saprobic or decay fungi and the beech forest dominated by ectomycorrhizal fungi.   The latter group forms a mycorrhizal association with the roots of the beech exchanging mineral nutrients for more complex carbohydrates, whereas saprobic fungi survive by decaying wood and leaf litter.   The forayers concentrated on mushrooms as this is the easier of the groups to identify, although a few woody brackets and other fungi found their way on to the ramble below.

On standing dead wood in the broadleaf podocarp forest we saw the pure white and slimy mushroom, Oudemansiella australis, large pale brown mushrooms of Agrocybe parasitica with its large membranous ring forming a substantial skirt on the upper stem, and the dark brown and rubbery brackets of Auricularia cornea.   Also on standing wood was the little, stemmed, brownish-white Beenakia dacostae which has teeth instead of pores or gills on its underside.   On the ground on fallen wood and twigs were Crinipellis procer, the horse hair mushroom, with its long, tough, almost black stem, and the small, white Mycena austrororida with a thick, clear layer of jelly coating its stem, and Clitocybe wellingtonensis with its funnel shaped cap and white root like rhizoids permeating the rotten wood on which it grows.   The greyish and delicate Mycena cystidiosa, the dull red Mycena ura, whose stem bleeds red juice when broken, were two easily identified Mycena species growing on twigs in the little.   Also in the woody litter was the bright orange pouch fungus Weraroa novaezelandica.

As we climbed to the drier ridge top, we moved into the Nothofagus forest and saw the fruit bodies of ectomycorrhizal fungi.   These included Amanita pekeoides which is greyish brown, lacks a ring, but has a large fleshy egg at the base of its stem, from which it hatched.   All through this area is a common large, whitish, fleshy Hebeloma which forms sometimes in fairy rings, but more often in large arcs under the beech.   New Zealand has many species of Russula and Cortinarius and most are difficult to identify however, we saw a few more easily recognised species such as the white Russula albolutescens and the small, bright red, almost not opening fruitbody of R. miniata buried in the litter, and the golden brown Cortinarius castaneus.

Russula is easily recognised by its white gills, lack of a ring and stem that snaps like chalk.   Similarly Cortinarius is recognised by its wispish, fibrous ring or cortina, and its brown gills; also many species have tints of blue or purple on the stem and young gills.   Only one bolete was seen and this was the big, chocolate brown, velvety Tylopilus formosus with its pink pore surface.   Some with keen eyes also found the fans and rosettes formed by the dark brown to black Phellodon sinclairii which like Beenakia dacostae has teeth instead of gills or pores.   Growing on beech wood was the large, woody, grey-brown brackets of a Ganoderma with its whitish pore surface.   In contrast, lying on the ground were the soft, wet masses of Piptoporus portentosus which soak up enormous amounts of water during wet weather and then proceed to fall out of the trees because of their increased weight.   In contrast to these large dull brackets were the troops of the little, fleshy brackets of Favolaschia calocera which are bright orange and can absolutely cover small branches with their fruitbodies, and the red-orange Paurocotylis pilea which is like a little puffball in the litter that does not puff and when cut in half is hollow and white.

As we headed back to the car park, the group passed through a stand of Douglas fir where there were ample mushrooms of Amanita muscaria, an exotic mycorrhizal fungus, with its red cap and white spots.   Also along the track edge were the puffballs of Lycoperdon perlatum.

For those who want to pursue the larger fungi further, some useful books are:
• Marie Taylor, 1981: Mushrooms and Toadstools.   Mobil New Zealand Nature Series.   AH and AW Reed, Wellington.   ISBN 0589013548
• Greta Stevenson, 1994: New Zealand Fungi, an Illustrated Guide.   University of Canterbury Press, Christchurch.   ISBN 0908812299
• Don Horn, 2000: Mushrooms and other Fungi of New Zealand.   Reed New Zealand Nature Series.   Reed, Auckland.   ISBN 0790007282
• Bruce Fuhrer and Richard Robinson, 1992: Rainforest Fungi of Tasmania and South-east Australia.   CIRO Editorial Service, Melbourne.   ISBN 0643053115

Geoff Ridley, Science Manager (New Organisms), ERMA