Cyphella Digitalis Was May, , „ O
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Acta Botanica Neerlandica 15 (1966) 95-101 A reassessment of the Cyphellaceae 1) M.A. Donk (Rijksherbarium, Leiden) (received November 23rd, 1965) A suitable subtitle for this paper would have been “The rise and of fall a family”. What is usually called the Cyphellaceae is an instructive encountered the example of a situation not uncommonly in current systematics of mycology: a family retained in a traditional sense by and considered them some mycologists by as good a family as any, others that it is bin from while are convinced nothing but a handy which the has been taken part of contents already out and disposed of by scattering it over various groups, but which is still needed for what remains. keeping We do not yet know what to do with this the considerable remainder, mainly because published accounts are inadequate and the species have not yet been scrutinized anew in the light of present-day taxonomic requirements. In the the the order to understand basic idea of Cyphellaceae type The that species be briefly introduced. fact Cyphella digitalis was may, , „ o . is and originally described as Peziza digitalis telling, one could not do better than characterize it as a ‘discomycete’ with basidia, viz. a cup-shaped fruit-body with the hymenium lining the smooth inside If form or ‘disk’. one were pressed to an opinion about its taxonomic and without the aid position from a dried, not annotated collection of the microscope, one would even now, very likely, dispose of it as there is little doubt that in a discomycete. However, nature the cup is directed downward at least when mature, in contradistinction to the in which the asci average discomycete hymenium containing the is the directed upward. This difference is a reflection of two modes of violent inherent spore discharge in the hymenomycetous basidium it has Buffer’s and ascus; been explained through well-known re- searches. The in various cups the species are not always typically in number cup-shaped; a they are more or less tubular or else more flattened and even disk-like. Once their true nature was recognized these discomycete-like basid- in iomycetes had to be reclassified the system of the Hymenomycetes. ‘ Since the hymenium is smooth, the Thelephoraceae’ became the for receptacle the species with more or less scattered fruitbodies In other fruitbodies crowded (Cyphella). species the may be so densely that together they simulate the pore layer of the ’Polyporaceae‘. In Solenia the ‘tubes’ seated (correct name, Henningsomyces ) are directly the In on substratum. Stromatoscypha (originally Porotheleum) they are x This is of the of lecture delivered the Third ) paper an adaptation text a at European Mycological Congress, held in Glasgow. 95 96 M. A. DONK crowded well-defined on a membranous stroma, common to a colony. Hence these became authors the fungi to some members of ’Poly- poraceae‘. This was, roughly, the situation when Patouillard (1900), after decided assemble these preliminary steps by Quelet and Schroeter, to discomycete-like Hymenomycetes into a taxon (subtribus) of their own. He admitted the with genera Aleurodiscus, Cytidia, Cyphella (fused Solenia), Porotheleum, Punctularia, and Phaeocyphella. Later mycologists for minor usually kept to Patouillard’s circumscription except some alterations, such as the exclusion of Aleurodiscus, and still more unanimously, of Punctularia. After some time the taxon was raised to the rank of definition of which a family, a simple runs: tube-, cup-, or disk-shaped fruitbodies with the smooth or slightly wrinkled basidial the viz. hymenium lining inside, the concave to flattened or even disk. slightly convex of The assignment Punctularia to the cyphellaceous fungi was un- expected. Patouillard was the first to discover that the knobs and folds of the hymenial surface (often likened to that of typical species of of the what Phlebia) resupinate fruitbody were not really they ap- peared to be, but were distinct cushions covered by the hymenium and sterile This led him conceive the separated by narrow, troughs. to only species he knew as comparable to Stromatoscypha but with convex rather than concave individual fruitbodies seated on a common subicular layer. has It sometimes does not take long after a family become estab- lished to attract elements that tend to obscure its original character; This in this it then grows out par enchainement. happened case, too. the Thus, Fistulina was assigned to family. Another introduction was later Chlorocyphella, believed to be a lichenized cyphella. At a much followed stage the genera Campanella, Leptoglossum, Arrhenia, Rimbachia, and Flavolaschia. In this various elements were added that con- way siderably departed from the straightforward original conception: for of elements and instance, some these had laterally stalked caps, others a strongly veined to almost lamellate or even tubulate hyme- nium. With these additions the family was raised to the rank of a suborder and divided into three families, Cyphellaceae, Leptotaceae, and Fistulinaceae. However, none of these innovations has found much general support. As Let us briefly examine some of these accretions. soon as a of the of rather divers- relationship between two groups magnitude it is traffic ified families is postulated apt to become a two-way bridge. This is what also happened in connection with the Polyporaceae, Fistulina been considered of which has a good example by many till mycologists up to-day. Solenia with the Persoon was the first to compare (Henningsomyces) resupinate species ofPolyporus (viz. the modern artificial genus Poria). when The separate fruitbodies are often elongate to cylindrical and densely arranged they do closely resemble porias. Fries went a step classed Solenia well in further and as as Porotheleum (Stromatoscypha) A REASSESSMENT OF THE CYPHELLACEAE 97 the The theoretical Polyporaceae. implication behind this was that Solenia had free tubes represented by the individual fruitbodies which are seated the directly on substratum; Porotheleum, free tubes on a distinct, membranaceous subiculum quite common to the wholecolony; and that in Fistulina the subiculum was replaced by an extremely stalked and well-developed laterally fleshy-fibrous succulent cap, but all the also same bearing free tubes. The bridge that served Fries to transfer Solenia and Porotheleum to the neighbourhood ofFistulina and into the has Polyporaceae been used by some modern authors to transfer Fistulina into the Cyphellaceae. Another quite remarkable two-way bridge is between the Cyphel- laceae and the it be Corticiaceae; may called after Aleurodiscus. This has become and genus gradually more more a storehouse of cor- ticiums with some kind, any kind, of so-called paraphyses. It is not this artificial Aleurodiscus I have genus in mind, but the one as recently redefined, in which the development of the basidia and amyloid an role in the The spore-wall play important generic character. type is Aleurodiscus held to be small species amorphus, originally a cup- in it is fungus: outer appearance certainly like a discomycete and If hence one extends the cyphellaceous. gradually genus par en- chainement it appears quite justifiable to penetrate more and more into the crowd of cyphellas and to enlist in Aleurodiscus such fine, big, cup-shaped fungi like Cyphella vitellina from South America. One also realizes to his astonishment that the of very type species Cyphella itself is in certain features similar (C. digitalis) very to these cup-shaped of Aleurodiscus. species Patouillard was quite correct, one would con- make Aleurodiscus clude, to a genus of the ’Cyphellaceae)‘. However, the of Aleurodiscus in surveying species another direction one soon such A. with comes across species as aurantius, a fungus completely and in all ‘resupinate’ (effused) fruitbodies respects ideally corticia- ‘ the ceous and belonging to Thelephoraceae' of the traditional clas- sification. It was natural that authors some placed Aleurodiscus in its ‘ entirety, as well as Cyphella reduced to its type species, in the Thele- phoraceae' or in a segregate thereof, the Corticiaceae•—and thus excluded Cyphella from the ’Cyphellaceae‘. Another example is the Leptoglossum bridge. Leptoglossum reminds in far that it one of Aleurodiscus so is partially typically cyphellaceous in the traditional sense. The smallest of its species (let us call it but this is Cyphella muscicola, not the correct name) is more or less and has a smooth It cup-shaped, hymenium. very closely resembles fruitbodies of L. young retirugum. Next come the species that have been in distinct placed a genus Leptotus, now fused with Leptoglossum. They are Leptoglossum retirugum and L. lobatum ; both are . _ _ , initially dorsally attached and finally attain far bigger dimensions and have a to throw their into folds which pronounced tendency hyménium may become and in radially arranged appearance somewhat gill-like with cross-veins. Then follows Leptoglossum muscigenum with a distinct but short lateral then rickenii stalk; Omphalina with erect, centrally stalked fruitbodies and folds well enough developed to include it in the 98 M. A. DONK in agarics; and finally we arrive at Pleurotus acerosus with gills optima forma. All these species have the same hyphal structure, the same the general form of spores of about the same dimensions; same brownish or greyish-brown colours with corresponding membrana- pigments encrusting the outer hyphae; and the same habitat, for they all The coherent all are moss-loving. series appears so perfectly that its species are now placed by some authors in the single genus Lepto- glossum. So far about of the late influx of some examples relatively genera which do not well conform to the traditional character of the Cyphel- other it laceae. On the hand has not yet been fully realized that if a broadly conceived family of Cyphellaceae is to be maintained, the genus Schizophyllum has carefully to be weighed for admission. It is of but is The now classed as a genus gill-fungi this not correct.