Observation 157303: Multiclavula mucida (Pers.) R.H. Petersen

Code: Bot_768/2013_DSC9098

Habitat: Mixed wood, dominant trees Picea abies, Fagus sylvatica, Fraxinus ornus, Fraxinus excelsior, Corylus avellana; at the foot of steep mountain slope, southeast oriented terrain, locally almost flat ground consisting of overgrown calcareous scree, rocks and boulders; in shade, partly protected from direct rain by tree canopies, average precipitations ~ 3.000 mm/year, average temperature 7-9 deg C, elevation 625 m (2.050 feet), alpine phytogeographical region.

Substratum: large, dead, rain soaked trunk of Picea abies in the last stage of disintegration lying on ground.

Place: Lower Trenta valley, next to the Soča trail between Markov bridge and Trenta village, right bank of river Soča, East Julian Alps, Posočje, Slovenia EC

Comments: Most sources consider this species as rare, however in Bovec region it doesn’t seem so. I’ve found it several times. One could consider it as frequently overlooked species partly because sporocarps are really small and because they are very ephemeral. However, on other side, it usually thrives gregariously in hundreds of sporocarps, which is, because of their white color contrasting to usually darkly colored rotten wood, quite easy to observe. This interesting fungus grows in symbiosis with algae (Coccomyxa) similar to lichens. While in true lichens algae are internal to fungi body, algae associated with Multiclavula mucida grow externally to the fungus on the same substratum. Algae can be observed like a thin layer of something green spreading around fungi sporocarps. M. mucida is also a rare example of symbiosis of a basidiomycete and algae. Vast majority of lichens is an association of ascomycete with algae.

Growing in groups of many fruit bodies; sporocarps up to 4 – 7 mm high and about 0.8 mm in diameter; most sporocarps are single, but some are branched into 2(max 5, one sporocarp found) tips; SP faint, whitish.

Measured spores are definitely wider than they should be for M. mucida. They with certainty belog to this observation because they come from tiny but clear spore pint. All sources I found consistently state that spore width should not exceed 3.0 (3.2) μm. According to the key (Ref.:(4)), only three other Multiclavula species (among 13 treated) fit to the spore dimensions measured: M. fossicola, which doesn’t have hypha clamps, M. coronilla, which is terrestrial and M. clara, which is not white but pale orange. Therefore measured spore width remains a secret to me. Any comment wellcome.

Nikon D700/Nikkor Micro 105mm/f2

Species Lists


Spore dimensions do not fit to data from literature-
Basidia dimensions and shape fit well to expectations for M. mucida
Hypha with clamps.

Proposed Names

28% (1)
Eye3 Eyes3
Used references: (1) J. Breitenbach, F. Kraenzlin, Eds., Fungi of Switzerland, Vol.2. Verlag Mykologia (1986), p 342.5.5-7.5/2.5-3
(2) G.J. Krieglsteiner (Hrsg.), Die Grosspilze Baden-Württembergs, Band 2, Ulmer (2000), p 43.
(3) R.H. Petersen, Multiclavula mucida, Bull. New Zealand Dept. Sci. Industr.Res. 236 (1988), p 85, access available at www.mycobank.com .
(4) The key based on R.H. Petersen, Notes on Clavarioid Fungi. VII. Redefinition of the Clavaria vernalis-C. mucida, American Midland Naturalist (1967), 77.1, pp 205-221, modified by A. Rockefeller, J. Hollinger, D.Newman, available at MO.
Based on microscopic features: Spores smooth; dimensions: 7.2 (SD = 0.9) x 3.6 (SD = 0.3) μ, Q = 2.0 (SD = 0.16), n = 30. Olympus CH20, NEA 100x/1.25, magnification 1.000 x, oil, in water, congo red. Basidia oblong with narrow, stalk like, base and with clamps; dimensions: 20.1 (SD = 1.9) x 7.0 (SD = 0.9) μ, n = 18. Hypha diameter 3.3 (SD = 0.4) μ, n= 30, with clamps, seems monomitic. NEA 40x/0.65, magnification 400x, in water, congo red. AmScope MA500 digital camera.
Based on chemical features: No distinctive smell, taste slightly bitter.

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Eye3 = Observer’s choice
Eyes3 = Current consensus


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Created: 2014-01-06 13:22:17 CST (-0500)
Last modified: 2014-01-06 13:22:31 CST (-0500)
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