Author Institution: Cincinnati Water Research Laboratory, Cincinnati, OhioA collection of the fungus Ascocorticium anomalum (Ell. & Harkn.) Schroet., was made in Ohio, on Nov. 4, 1961, by Harry Knighton and W. B. Cooke, in Hobey's Hollow, Shawnee State Forest, Scioto County. This fungus was named after comparison with 15 other collections of this species from four herbaria in the United States. It is suggested that Basidiomycetes might have arisen from a genus like Ascocorticium, where the amount of sterile tissue is reduced in comparison with the amount of ascogenous tissue

Cooke, William Bridge

The Ohio Journal of Science

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ASCOCORTICIUM IN OHIO1WILLIAM BRIDGE COOKECincinnati Water Research Laboratory, Cincinnati, OhioABSTRACTA collection of the fungus Ascocorticium anomalum (Ell. & Harkn.) Schroet., was made inOhio, on Nov. 4, 1961, by Harry Knighton and W. B. Cooke, in Hobey's Hollow, ShawneeState Forest, Scioto County. This fungus was named after comparison with 15 other col-lections of this species from four herbaria in the United States. It is suggested thatBasidiomycetes might have arisen from a genus like Ascocorticium, where the amount ofsterile tissue is reduced in comparison with the amount of ascogenous tissue.The finding of a specimen of the fungus Ascocorticium is considered by my-cologists as unusual and significant for the area where it was collected. In Ohio,the first recorded specimen of this genus was collected on Nov. 4, 1961, by HarryKnighton, then Chairman of the People-to-People Committee on Fungi, and thewriter. In the attempt to name this fungus, all available materials in the UnitedStates and Canada were studied. Specimens were loaned by the curators of thefollowing herbaria, whose kindness is here acknowledged: the National FungusCollections (BPI), the New York Botanical Garden (NY), the University ofMichigan (MICH), and the University of Toronto (TRTC). This report sum-marizes the data on all specimens of Ascocorticium found in these herbaria. TheOhio specimen agreed well with the other specimens studied and may be describedas follows:Ascocorticium anomalum (Ell. & Harkn.) Schroet.Engler & Prantl, Nat. Pflanzenfam., Ed 1(1): 161. 1897.Ascomyces anomalum Ell. & Harkn., Bull. Torr. Bot. Cl. 8: 26. 1881.Ascocorticium albidum Brefeld, Unters. 9: 145, t. 1, f. 37-39. 1891.Exoascus anomalus (Ell. & Harkn.) Sacc, Syll. Fung. 8: 820. 1889.Fructification resupinate, white, initially appearing as a circular, effused growth up to5 mm in diameter, becoming confluent on the bark surface; formed of a compact basal myceliallayer; hyphae 1.5-2.5 M in diameter, with subgelatinous walls, strongly branched, arrangedsomewhat irregularly, without marginal or peridial hyphae. Basal mycelial layer thin, upto 10-20 ju thick, giving rise to a loose layer of asci and paraphyses. Paraphyses frequent,18 x 1.5 fx, hyaline, hypha-like. Asci with croziers at the base, with a thickened wall nearthe tip, 18 x 5 /*. Spores biseriate to irregularly arranged within the ascus, smooth, cylindricor long-ovate, hyaline, 4.5-5.5 x 1.8-2.1 /x.Ohio: Scioto County: Hobey's Hollow, Shawnee State Forest. Collected Nov. 4, 1961,by Harry Knighton and W. B. Cooke (WBC 33090) on old bark (oak?).Non-Ohio specimens examined number 15. These include No. 306 of Otto Jaap's Fungiselecti exsiccati collected from the inside of bark on a stump of Pinus silvestris, Schleswig-Holstein, Germany, (BPI); No. 561 of Ellis' North American Fungi, collected in 1880 by Ellisand Harkness from bark of old pine logs at Newfield, New Jersey, probably the type ofAscomyces anomalus Ell. & Harkn. (BPI, NY, MICH); No. 98, Reliquiae Farlowianae, col-lected in 1914 on Pinus rigida by A. P. D. Piguet at Sharon, Massachusetts (BPI, NY, MICH,TRTC); No. 1102 of Rehm's Ascomyceten, collected by Dr. v. Tavel on Pinus sylvestris atMunster, Germany, in 1893 (BPI), apparently from the same location, host, and by the samecollector as the type of Brefeld's species. In addition to these exsiccati reports, two specimensof Ellis and Harkness' type collection are filed, one in the National Fungus Collections and onein the New York Botanical Garden; at the New York Botanical Garden is a collection madeby W. D. Graddon at Rushton, Staffordshire, England, on Calluna, Jan. 5, 1952; and at theUniversity of Toronto is a specimen from Douglas fir bark collected at Comstock, Oregon, onDec. 11, 1937, by A. M. and D. P. Rogers.Manuscript received February 28, 1967.THE OHIO JOURNAL OF SCIENCE 68(3): 161, May, 1968.162 WILLIAM BRIDGE COOKE Vol. 68All of these non-Ohio collections agree well with the Ohio specimen describedabove. There is slight variation in spore, ascus, and paraphysis measurements.Some of the initial fructifications measure as little as 1 mm in diameter, but innone of the specimens did there appear to be reason to believe that more speciesexist in the group of specimens studied.Specimens of Exoascus albidum var. aphthosum Bommer, Rousseau, and Saccardoin Sacc, with ascospores 6 x 2.5 /J,, and Ascocorticium effusum Rodway, with spores12-15 x 6 n, were not available for study.In the Ascomycetes, there are two systems of hyphae in the fruit body, thebasic tissue of the structure which, in studied material, contains only one nucleusper cell, and the ascogenous tissue which arises from this in one of several waysand in which, in studied material, there are two nuclei per cell, which divide con-jugately until the ascus is reached. This ascogenous tissue is considered to beN+N, with one nuclear phase in the ascus representing a 2N phase. In Asco-corticium, only the paraphyses and their subtending cell system are of the Nphase, while the asci and their subtending cell system are of the N + N phase.Ascocorticium, as a genus, is of interest because its fruit body possesses a minimumof N-phase tissue in comparison with other discomycetous genera. In the latter,there is an abundance of N tissue supporting and enclosing the N + N tissue,whose primary function appears to be the completion of the sexual phase of thelife cycle and the production of ascospores. There is no peridial tissue and thereare some paraphyses. Although some observers have reported seeing no para-physes, these structures were observed in all specimens examined. The asci haveappeared to some to be inoperculate, although Gaumann and Dodge (1928) includethe genus in the Rhizinaceae, a family of operculate Discomycetes. Gaumannand Wynd (1952) assign the Ascocorticiaceae to the Helotiales, indicating that itprobably forms a transition between the Gymnoascaceae and the more primitiveHelotiales. Although Ellis placed his species in the genus Exoascus, most recenttreatments assign the Ascocorticiaceae to the Helotiales with other inoperculatespecies. To me, the asci appeared inoperculate, although careful studies on thecytology of this fungus are required to answer several of the more critical ques-tions concerning its nuclear phenomena.In the definitely operculate Discomycetes, there is an unrelated genus,Ascodesmis, which also has a reduced amount of N tissue in comparison with thepotential amount of N+N tissue of the fruit body. That genus has recentlybeen monographed by Obrist (1961), who described A. sphaerospora from a cul-ture obtained from sewage sludge by the writer at the Dayton, Ohio, sewagetreatment plant. The five species of Ascodesmis are known mostly from dungfrom many parts of the world. In this genus the spores are beautifully ornamented.The family name Ascodesmidaceae has been mentioned by Nannfeldt (19,32), butno formal publication of it has been found.In discussing the phylogeny of the fungi, especially in reference to the relation-ships between the Ascomycetes and the Basidiomycetes, some authors have de-rived the Basidiomycetes from the Ascomycetes through areas where a reductionin N tissue appeared, resulting in an apparent increase in N + N tissue. Accord-ing to Gaumann and Dodge (1928) and Rogers (1934), the genus Ascocorticiumpresents a good example of such a transition fungus, with a corticioid representa-tive of the Hymenomycetes completing the bridge across the gap between thesetwo classes. It may be suggested also that Ascodesmis could represent a fungusthat might bridge another gap between these two classes, the basidiomycetousrepresentative of such a bridging group being a member of the astrosporiaceousgroup, which includes various hypogaeous genera and the genera Russula andLactarius.Whether these genera represent terminal stages in the evolutionary develop-ment of inoperculate and operculate lines of Ascomycetes is a question that canNo. 3 ASCOCORTICIUM IN OHIO 163be argued indefinitely. The response of these fungi to their environmental con-ditions has resulted in a reduction in the amounts of peridial tissue in their fruitbodies as well as in the amount of N tissue supporting the N + N tissue producingthe asci. Such a response can represent different things to different people. Oneof these points of view is briefly described here.REFERENCESGaumann, E. A. and C. W. Dodge. 1928. Comparative Morphology of Fungi. New York,McGraw-Hill Book Company, xiv-701 pp.and F. L. Wynd. 1952. The Fungi. Hafner Publishing Co., New York. 420 pp.Nannfeldt, J. A. 1932. Studien iiber die Morphologie und Systematik der nichtlichenisierteninoperculaten Discomyceten. Nova Acta Regiae Soc. Sci. Upsaliensis. Ser. IV. 8(2):1-368.Obrist, W. 1961. The genus Ascodesmis. Canad. Jour. Botany 39: 943-953.Rogers, D. P. 1934. The basidium. University of Iowa Studies, Studies in Natural History16: 160-181.

Ascocorticium in Ohio

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Ascocorticium in Ohio

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