Finding Chaetodermella lunaand other exciting corticioids
in Scottish pinewoodsLiz Holden*
Corticioids are a group that I have longwanted to get to grips with although, inall honesty, when occasionally I ‘had a go’,
more often than not the collection was abandonedin frustration – just not sure what I was actuallylooking at. The BMS corticioid workshop led bySwedish expert, Karl-Henrik Larsson inFebruary 2012, the availability of a new textFungi Europaei 12: Corticiaceae (Bernicchia &Gorjón, 2010), the purchase of a second-hand setof The Corticiaceae of Northern Europe(Hjortstam et al., 1973) and finding some timehave really moved things on for me.
Leading up to the workshop, I decided that Iwould collect one corticioid a day and just workon that without the pressure of any other collec-tions to worry about. I would not be put off by thefirst appearance of a tangled mass of hyphae butequally, if after a good look around I couldn’t
make any progress in the key, then I would ditchthe collection and try again the next day. Thisapproach seemed to work well and, althoughquite a lot were abandoned initially, I started tosee differences and pick out features that evenled to the occasional naming of a collection. Thefact that some of these determinations turned outto be correct (my thanks to those at the workshopwho took the time to look) encouraged me tocontinue.
What happened next is also a reflection of thewonderful area in which I live, on the Mar LodgeEstate, near Braemar, Aberdeenshire, owned bythe National Trust for Scotland, with old growthCaledonian pinewoods literally on my doorstep(Fig. 1). I decided to walk out to one of the remoteareas of pine and make 20 collections of corticioidfungi. Working through them over the next fewdays, I found myself with one that consistently
*Allanaquoich, Mar Lodge Estate, Braemar, Ballater, Aberdeenshire AB35 5YJ
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Vol 14 (2)keyed out as Chaetoderma luna (nowChaetodermella luna), which if confirmed wouldbe new to Britain (Fig. 2).
This is really a rather unremarkable lookingcorticioid at the macroscopic level. Under themicroscope however, some very distinctivefeatures are revealed. The spores are immedi-ately striking, being large (av. 16 x 5.5 µm) andrather crescent-shaped, hence the specificepithet. The 4-spored basidia are notably longand slender, measuring up to 105 µm long in mycollection. Cystidia were present and protrudingfrom the hymenium, more or less cylindrical,thick-walled, finely encrusted and also very long,measuring up to 300 µm. FE12 states that thisspecies is associated with Juniperus oxycedrus inits single Italian site, which initially caused meto doubt my conclusions. Here of course is thebenefit of having more than one text to consult,as Hjortstam et al. (1973) suggest that it isassociated with dry, decorticated conifer wood,mostly of Pinus sylvestris. This latter habitat is aperfect fit for my collections, both of which werefrom the side of a fallen trunk in relatively dryconditions. Interestingly, neither text mentionsany particular smell whereas my second collec-tion had a distinctly spicy smell reminiscent ofthe peppery smell of Stropharia pseudocyanea. Idid not notice this with the first collection but
will certainly be looking out for it in the future, asit would be an excellent field character to add tothe description.
Alick Henrici and Martyn Ainsworthconfirmed my initial identification; I did indeedhave a new British record. Chaetodermella lunaseems to have a particularly continental distribu-tion and is locally common in the continentalareas of eastern Norway. Elsewhere, the distri-bution is sporadic, it is usually found in old forestreserves. The Scottish collection certainly fits inwith this pattern, since it was fruiting in an areaof old growth pine, in the most continental part ofScotland. These ecological requirements suggestthat the species is unlikely to be found commonlyin Britain but I will certainly be keeping my eyeopen in other old pinewoods.
Now seriously hooked, during April and Mayof 2012, I visited all eight compartments of oldgrowth pine on the Mar Lodge Estate, andrecorded a total of 47 corticioid species, all withPinus sylvestris. These included three furtherspecies new to Britain (Phlebia cretacea,Phlebiella subflavidogrisea and Sistotremabinucleospora), two species (Phlebia subcretaceaand Tubulicrinis effugiens) with previous singlerecords but listed as Excluded in the BritishChecklist as no voucher material was everdeposited and a further 22 species that have been
recorded on less than 12 other occasions inScotland.
Of these 22 species of interest, perhaps themost distinct is Odonticium romellii (Fig. 3). Thiscan cover large areas of damp, well-rotted, fallenconifer wood with a reasonably robust, white,toothed encrusting fruitbody. It appears to be aregular feature of the old growth forest at MarLodge occurring in five of the eight compartmentsbut so far in none of the plantation areas checked.Up until this study, it was known in Britain onlyfrom four Scottish collections. Microscopically itlacks cystidia and clamps and has small, slightlyallantoid spores (av. 4.0 x 1.5 µm). The mostobvious micro-character is the rather thickwalled hyphae that make up the teeth. Thesehave numerous constrictions along their lengthgiving a very distinctive appearance in thesquash preparation.
I have found corticioids a fascinating group towork with although obviously using a microscopeis essential and trying to be sure of the number ofsterigmata on tiny and elusive basidia is noteverybody’s cup of tea. Many of the specieshowever, have lovely microscopic characters and,as with any group, once you have become familiarwith them, the identification process becomesmuch easier. Add to this the fact that corticioidscan be found in fertile condition in damp situa-tions all through the year and what more couldyou wish for?
AcknowledgementsI would like to thank Karl-Henrik Larsson for amost excellent workshop, Martyn Ainsworth,Alan Lucas and particularly Alick Henrici foralways helping and offering encouragement andthe National Trust for Scotland who own andmanage Mar Lodge Estate and are always inter-ested in what I find there.
ReferencesBernicchia, A. & Gorjón, S.P. (2010). Corticiaceae
s.l.. Fungi Europaei 12. Ed. Candusso. Italy.Hjortstam, K., Larsson, K.H. & Ryvarden, L.
(1973). The Corticiaceae of North Europe Vol 2 Aleurodiscus – Confertobasidium. Fungiflora, Oslo, Norway.
