September 29th - Fungus Foray in Belvoir Forest and Barnett Demense.


Conductor; Alistair McCracken

Our leader, Alistair McCracken, is a plant pathologist so his expertise extends to microfungi such as blights, rusts and moulds as well as macrofungi.  In Belvoir Forest he showed us Lawson Cypress trees killed off by the blight Phytophorum lateralis which originated in Oregon and is spread in soil, so it’s important to clean one’s boots after contact. The related Phtyophorum ramorum, first detected in trade plants, affects larch and rhododendrons and is spread through the air.  Chalara Fraxinea, which is threatening to destroy our native Ash (Fraxinus excelsior) has been detected on plants imported from Europe. As Ash trees seed so prolifically, one wonders why nurseries have to import them. Alistair showed us chestnut trees cut down because of cankers caused by a Pseudomonas bacterial infection and powdery mildew on Oak leaves. The black spots (Rhytisma acerinum) on sycamore leaves, are more common in areas of clean air and do not appear to harm the trees. Rust is common on Blackberry leaves – the Botanical secretary had photographed, in the Canary Islands, a green Tree Frog (Hyla meridonalis) with camouflage red spots – the frog was almost invisible on a rust-covered bramble leaf.

The fungi we see are the fruiting bodies of saprophytic mycelia which can spread over vast areas underground. The largest living organism in the world is a 2200 year old Mycelium covering 2400 acres in eastern Oregon.  Mycelia play a vital role in the decomposition of plant matter. The mycorhiza - a name given to the type of fungus which forms a symbiotic, usually mutualistic relationship with other plants, notably orchids, help them take up nutrients from the soil. Thus many fungi, such as the Larch Bolete (Suillus grivellei) and the Beechwood Sickener (Russula mairei) are associated with particular trees.

On a fine morning we assembled first in Belvoir Forest where we soon found many fungi associated with woodland. Clumps of yellow Sulphur Tufts (Hypholoma  fasciculare) and Honey Fungus (Armillariella mellea) were photographed.  We handled the moist, rubbery Jelly Ear (Auricularia auricula-judae), growing on dead Elder; it is also known as Jew’s Ear because Judas was supposed to have hung himself on an Elder tree. 

Orange Peel fungus (Aleuria aurantia) is edible but tasteless. Candle-Snuff Fungus (Xylaria hypoxylon) grows on decaying wood of broad-leaved trees –“xylon” means wood.

In the afternoon we set off from Shaw’s Bridge over the Barnett Demesne meadows looking for Wax Caps – Orange Wax Caps (Hygrocybe aurantia) were growing near Fairy Ring Mushrooms (Marasimius oreades) – these add nitrogen to the soil so the ‘fairy ring’ is greener than the surrounding grass.  Penny-bun (Boletus edulis) is a main ingredient of mushroom soup.

Distinctive fungi included the Amethyst Deceiver (Laccaria amethystea) and the shiny Porcelain or Slimy Beech Tuft (Oudemansiella mucida). There are over 100 species of Russula – R.emetica has the effect its name suggests. The only Puff-ball to grown on dead wood is Lycoperdon pyriforme  which means “Pear-shaped wolf’s dung”! Members examined and photographed many Bracket Fungi including Artist’s Fungus (Garnoderma adspersum ) on which one can scratch drawings, and Tramites/Coriolus versicolor with layers of banded velvety brackets. We took it in turns to go inside a hollow beech tree to admire Brackets growing all the way up the 3 metre hollow.

Examples of some of the fungi found were displayed at the Conversazione.  Alistair was thanked for sharing his expertise with us on a very pleasant and productive excursion.


Margaret Marshall

Thanks to Jim Rutherford for the use of the photographs.

 
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Honey Fungus (Armillariella mellea)

Jew’s Ear

(Auricularia auricula-judae)

Candle Snuff

(Xylaria hypoxylon)

Orange Peel fungus (Aleuria aurantia)

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