A wider and more natural concept of the genus Gyromitra Fr.

Harri Harmaja Department of Botany, University of Helsinki, Helsinki, Finland.

In the course of my studies on the genus Pseudorhizina Jacevskij. This monotypic Gyromitra I have found it unavoidable to genus has been established for H elvella expand the concept of that genus so as to sphaerospora Peck because of the spherical include three genera usually considered sepa­ spores of the latter. Subsequent authors (e.g. rate, essentially because of differences in EcKBLAD, op. c.) have not observed any other spore characters. Modern authors have trea­ «significant« difference between it and the ted Pseudorhizina J acevski j (Helvellella Gyromitra species. Though EKCBLAD in his Imai), Neogyromitra Imai (Maublancomyces revision of the genera o.f operculate Disco­ Herter) and the old genus Discina (Fr. ) Fr. mycetes writes that «in no case is it obvious as independent genera beside Gyromitra Fr. that a genus should be separated on spore EcKBLAD ( 1968 ) too, maintains these genera form alone« he still acknowledges the genus. except for Neogyromitra which he groups I have studied the lectotype of Gyromitra with Discina. On the other hand he writes gabretae Kavina, which belongs to P. sphae­ that «smooth versus ornamented spores is a rospora and found the excipulum to be com­ character o.f differentiating value on specific posed of textura intricata as described by level only«. BENEDIX ( 1962 ) has even estab­ EcKBLAD ( op.c. ). The spores are small and lished for N eogyromitra and Discina a family completely spherical and a perispore cannot of their own. be distinguished. The spore wall is about When delimiting the genus Helvella [L.J 0,5 flm thick as in species of Gyromitra. St.-Amans, Nannfeldt and Dissing (see Many spores seem to be completely devoid of DrssrNG, 1966) have emphasized the uniform oil drops but probably most of them, however, anatomy of the excipulum together with the contain one (some contain two or more) very characters o.f the spores as the uniting small eccentric drop. The various species of characteristics of that genus. The form of the G'yromitra s.lato have a characteristic number ascocarp is, on the contrary, most variable in and size of oil drops in most of their spores the genus, from subsessile to ones with a very but the drops can be lacking in a number of distinct lacunose stipe and a mitrate fertile even mature spores. The fact that I have cap. I have found their ideas to be valid and not observed any perispore in P. sphaerospora adaptable also in the delimitation of Gyro­ does not necessarily exclude the possibility of mitra. According to my studies, in Gyromitra, its existence. It may well be so thin and Pseudorhizina, Neogyromitra and Discina the tightly appressed to the spore wall that other anatomy of the excipulum (as observed by means than passive studying under the EcKBLAD, 1968, too) and the paraphyses are microscope are needed to detect it. much alike, and to a high degree the spores, I have studied some specimens of Gyro­ too. mitra californica (Phill.) Raitv. from Cali-

9 fornia and Idaho. This species is a true Gyro­ gu.a (s.n. G. infula v. apiculatispora Raitv.; mitr.a as verified by RAITVIIR ( 1965) and see HARMAJA 1969 ) the inflated perispore EcKBLAD ( op.c.) and it seems to be nearly­ although he thought it was «the thickened related to P. sphaerospora both macroscopi­ epispore membrane«. He did not, however, cally and microscopically. The spores of G. consider this discovery very significant and californica are small, ellipsoid, without an he merely suggested that Gyromitra and observable perispore and most of them con­ N eogyromitra should be placed in the same tain two very small drops, one at each end, tribus, but not united into one genus. Inde­ but often not symmetrically located. Viewed pendently of him I have observed a perispore from above, it is obvious that the spores of more or less inflated at the spore ends sur­ P. sphaerospora represent through those of round the spores of the same two species and G. californica one end of the variation of the of the type species of Gyromitra, G. escu­ Gyromitra spo-re and that the species belongs lenta, too. The periplasma stained always to that genus, where its correct name is Gyro­ deep blue in Cotton Blue as in N . gigas. In mitra sphaerospora (Peck) Saccardo. G. ambigua the inflations are rather wide and in some spores they are much like those Neogyromitra Imai. This genus has been of N. gigas. There is thus no principal diff­ established and used for stipitate species with erence between the spores of Gyromitra and «apiculate and sculpturate« spores. At least Neogyromitra, to the contrary of what has two valid species have been recorded in the been emphasized in the literature (see Fig. 1). genus, N. gigas (Krombh.) Imai and N . caro­ There is, however, a reticulum, composed of linian a ( [Bose J Fr.l Imai. an unknown substance, on the perispore of According to the studies of LE GAL ( 194 7) mature spores of N eogyromitra (and Discina; and my own, the appendages of the spores of see LE GAL, op.c." ) . According to EcKBLAD N. gigas are but inflations of the perispore ( op.c.) the excipulum in N. ( «Discina« I filled with some substance. The substance, g i ~ as (also verified by me) and N . caroliniana periplasma, which is located between the is throughout composed of textura intricata spore wall and the perispo-re stains deep blue which is the type of excipulum of Gyromitra in Cotton Blue. M AS GEESTERANUS ( 1965 ) s.str., too. N. gigas and N. caroliniana thus has found that the spores are principally differ from the three Gyromitra species named similar in N. caroliniana. The deep-staining above in that their mature perispore inflations of the perispore are, however, not has a reticulum. This is. an infrageneric restricted to these two stipitate species as it difference only and the two species must be has been supposed when maintaining this called Gyromitra gigas (Krombholz) Cooke genus. Probably RAITVIIR (op.c.) was the and Gyromitra caroliniana ( [Bose J Fries I first to find in G. infula and G. ambi- Fries.

c d e f g h

Fig. 1. Spores of some species of Gyromitra, drawn x 1 000 in heated Cotton Blue (the reticulum has not been drawn in f, g and h ) : a) G. sphaerospora (lectotype of G. gabretae), b) G. californica (Ida­ ho, leg. A. W. Slipp), c) G. esculenta (Finland, Laitila, leg. K. Alho, I. Kause & U . Laine), d) G. in­ fula (Finland, Lohja, leg. H. Harmaja), e ) G. ambigua (holotype), f) G. gigas (Finland, Jarvenpaa, leg. Y. Palmu), g) G. perlata (Finland, Lohja, leg. H . Harmaja) , h ) G. leucoxantha (type ) .

10 Discina (Fries) Fries. There are at least The emended genus Gyromitr.a Fr. thus two valid species in this genus, D. perlata contains distinctly to very shortly stipitate (Fr.) Fr. and D. leucoxantha Bres. From the terricolous or lignicolous, vernal to autumnal first-named I have studied several specimens species without dull colours (black, grey) and collected by myself and others; from D. leu­ mostly growing in the neighbourhood of coni­ coxantha the type and another specimen fers. The excipulum is -+- uniform throughout collected by Bresadola. The excipulum of and composed of interwoven, -+- filamentous both species is composed of textura intricata hyphae ( textura intricata). The spores are as observed by EcKBLAD ( op.c.) in the case ellipsoid or oblong or -+- fusiform, rarely of D. perlata. Their spores have a pronoun­ spherical, 1-, 2- or 3-guttulate, some to 'many ced perispore which is reticulate at maturity of them may, however, have no or many and in each species it is inflated in a charac­ guttules. The spores have a smooth wall ca. teristic way at the spore apices because of the 0,5-0,8 flm thick and are mostly (if not blue-staining periplasma. These characters always) surrounded by a perispore. The of the spo-res of both species have earlier been perispore, when present, is more or less in­ studied and described thoroughly by LeGAL flated (often in a characteristic manner) at ( op.c.). Accordingly, microscopically Discina the spore apices and the space between it and species differ only very slightly from «N eo­ the spore wall is filled with periplasma deep gyromitra«. The fruit-bodies of Discina have blue in Cotton Blue. The periplasma is a more or less distinct, mostly lacunose stipe accordingly most prominent at the spore (In D. perlata I have seen the stipe as long as apices. In some species the mature spores 2 em) . With age the hymenium usually gets have in addition a reticulum farthest off. folded and convex. Sometimes there is indeed It is very probable that G. infula (and not much separating Discina from «Neogyro­ G. tasmanica ? ; not studied by me) repre­ mitra«. The two genera have, however, nearly sents a rather primitive type in the genus. uniformly been treated as separate genera Assuming that the genus is monophyletic, because of the distinct stipe and gyrose hyme­ G. sphaerospora would thus represent one nium of N eogyromitra, the Discina species end of the variation in Gyromitra, viz. to­ being indistinctly to shortly stipitate and wards simpler and smaller spores with smaller having a discoid smooth hymenium at least to no oil drops but towards a well developed when young. EcKBLAD ( op.c.) is the sole fruit body (as also BENEDIX, 1962, has sugges­ author to consider these differences unsatis­ ted) whereas the Discina group would be at factory at the generic level and he united another end with the reverse evolution: the N eogyromitra to Discina. It is to be noted, development of large thick-walled spores with however, that in his article as early as 1930, a complex perispore and large and/or several CoRNER considered Discina perlata as a very oil drops, but the degeneration of the fruit nearly-related derivative of Gyromitra gigas. body. A less plausible possibility is that the This case resembles much the situation in the whole genus has evolved from Rhizina-like genus H elvella which includes both subsessile ancestors via the Discin.a group. I do not and distinctly stipitate species with almost consider it probable that the Discina group is uniform anatomy and spores. Accordingly, the most primitive one from which the stipi­ I agree with EcKBLAD and consider Neogyro­ tate Gyromitras would have evolved to one mitr.a and Discina congeneric. In the pre­ direction and Rhizina to another, opposite ceding paragraph I have, however, united one. Neogyromitra with Gyromitra, from which it The natural family Rhizinaceae Bon. sensu follows. that the Discina species must be in­ EcKBLAD (op .c.) contains beside the emended cluded in Gyromitra, too. Two new combina­ Gyromitra only one additional genus, Rhizina tions become necessary: Gyromitra perlata [Fr.] Fr. R . undulata (studied by me) has (Fr.) Harmaja, n. comb. (basionym Peziza spores very similar to those of G. perlata, but perlata Fries, Syst. 1v1yc. II, p. 43, 1822 ) it deserves a genus of its own because of the and Gyromitra leucoxantha (Bres.) Harma­ total lack of stipe, the «ditfuse« yellow margin ja, n. comb. (basionym Discin.a leucoxantha of the ascocarp, the rhizomorphs, and the Bresadola, Rev. Myc. 4, p. 212, 1882 ). For­ deviating anatomy with setae and almost tunately the name Gyromitra is older than globose cells in the outer excipulum. the name Discina.

11 LITERATUR'E

BENEDix, E. H., 1962: Zur polyphyletischen Her­ HARMAJA, H., 1969 : A neglected species, Gyro­ kunft der Helvellaceen ss. lat. - Zeitschr. rnitra ambigua (Karst.) Harmaja, n. comb. f. Pilzk. 27, 93-102. and G. infula s.str. in Fennoscandia. - Karstenia 9, 13- 19. CoRNER, E. H., 1930: Studies in the morphology J. LE GAL, MARCELLE, 7: Recherches sur les orne­ of Discomycetes. IV. The evolution of the 194 mentations sporales des Discomycetes oper­ ascocarp. - Trans. Brit. Myc. Soc. 15, cules. - Ann. Sc. Nat., Bot., 11e serie, 8, 121- 134. 73-297. DrssrNG, H., 19£6 : The genus Helvella in Europe MAAS GEESTERANUS, R. A., 19·65: Einiges iiber Neo­ with special emphasis on the species found gyromitra caroliniana. - Proc. Koninkl. in Norden. - Dansk Bot. Ark. 25 , 1-172. Ned. Akad. Wetensch., series C, 68, 128- EcKBLAD, F .-'E., 1968 : The genera of the oper­ 134. culate Discomycetes. A re-evaluation of RArrvrrR, A., 1965 : Taxonomical notes on the ~heir taxonomy, phylogeny and nomen­ genus Gyromitra. - Eesti NSV Tead. clature.- N. Mag. Bot. 15, 1-191. Akad. Toim. 14, bioi. seeria, 320- 324.

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