2011 Cain Foray Post-Mortem

by Anoja and Derek Giles

Sunday September 18thwas the last day of the foray. Foragers were given the option to sign up for a morning hunt or attend the ‘collection’ roundup given by attending guest mycologists……… Walter Sturgeon, Linda Kohn, Richard Summerbell and John Plischke.

Although Walter talked about Boletes, he began by drawing attention to a specimen of Cerrena unicolor which he found on Saturday. The mystique of this easily overlooked ‘ho hum’ polypore is its fascinating relationship with two wasps; the Horntail wasp and the Ichneumon wasp. A complex story but here is the basic plot. The fungi spores infiltrate the ovipositor of the Horntail wood boring wasp. They in turn germinate when the wasp eggs are laid. The resulting mycelium becomes food for the larvae of the horntail wasp. The Ichneumon wasp is parasitic on horntail larvae and thus becomes a predator controlling Horntail wasp populations. The mycological moral of the story is that pheromones emitted by Cerrena unicolor assist the Ichneumon wasp to locate the larvae usually deeply buried in beeches. Walter continued with a very informative summary of the two seasons of Boletes, Summer and Fall.

Next Linda Kohn talked about what she described as a “massively, monstrously, misdeveloped agaricus”…  the Giant Puffball which appeared on Saturday. DNA analysis has shown us that fungi that look different may be closely related and fungi that look similar may not be related at all. This fungus is classified under the order Lycoperdales as Calvatia gigantea however recent DNA analysis has shown it to be in the same family as Agaricus. In another example of a gasteromycete now known to be grouped with the mushroom-forming fungi here in a special stinkhorn subclass, Linda also mentioned Phallus ravenelii found on Saturday in Foray 3.  She explained that we were seeing a perfect example of the stinkhorn in all its stages of development. Stinkhorn ‘eggs’ were present, eggs with the stipe emerging through the veil, as well as fully mature fruiting bodies. She used the specimen to characterize spore dispersal by insects. The stinkhorn is at its most pungent at noon, attracting flies which in turn collect then disperse spores. In fact, fungi in the Zygomycetes, Ascomycetes and Basidiomycetes have found ways to use insects to disperse their spores. Scan the windows in your workplace or home; if you see a dead fly stuck on the glass in haze of white, you are seeing a fly parasitized by a relative of the pin moulds, Entomophthora, that shoots its spores from the unfortunate prey to very effectively infect other unsuspecting flies that might land nearby (flies tend to cluster).

Richard Summerbell stressed the difficulty of identifying specimens of Cortinarius due to deposits of their rust coloured spores which obscure the purple gills of the young fungi. Some species have a characteristic odour of geranium leaves, rotten potatoes or apples which can sometimes help. The most notable edible within this genus is “The Gypsy” Cortinarius caperatus, (caperatus = wrinkled, apparent on mature caps).  Prior to DNA re-classification, this mushroom was designated under the genus Rozites, named after European Ernst Roze. Richard drew attention to the cake frosting characteristic on the cap. The Gypsy is mycorrhizal with pine and oak but commonly found near hemlocks or pines.

John Plischke talked about edible fungi. He’s even eaten stinkhorns!!! He made reference to tasting the milk of Lactarius species to determine their suitability for the table. He advised a mild tasting milk to indicate edible Lactarius species generally whereas an acrid lactate was to be avoided. A favourite of his is Laccaria ochropurpurea. Edible Lactarius species are particularly favoured in northern Spain where entire festivals are devoted to this genus. John also mentioned his taste for Xerula furfuracea, the very long stemmed gilled mushroom, adding that he only eats the caps. I’m told the genus has been re-classified as Hymenopellis. 

A Plischke favourite to pickle is Hypsizygus tessulatus, the Elm Oyster, found in the fall often high up in living trees.

The roundup ended with the arrival of the morning foragers, baskets full with new specimens to identify.