Based on molecular and morphological data (Lutzoni & Vilgalys Reference Lutzoni and Vilgalys1995; Lutzoni Reference Lutzoni1997; Moncalvo et al. Reference Moncalvo, Lutzoni, Rehner, Johnson and Vilgalys2000), it has been shown that lichenized species of the genus Omphalina Quél. (Tricholomataceae R. Heim ex Pouzar now. cons.) constitute a monophyletic group that should be included in a separate genus Lichenomphalia Redhead, Lutzoni, Moncalvo & Vilgalys (Redhead et al. Reference Redhead, Lutzoni, Moncalvo and Vilgalys2002). The genus was proposed for eight species with vegetative lichenized thalli ranging from a bulbilliferous (Botrydina type) to a squamulose (Coriscium type) thallus, with Coccomyxa algae (Redhead & Kuyper Reference Redhead, Kuyper, Laursen, Ammirati and Redhead1987). Barrasa & Rico (Reference Barrasa and Rico2001) studied in detail four lichenized Omphalina species from the Iberian Peninsula: Lichenomphalia umbellifera (L.: Fr.) Redhead, Lutzoni, Moncalvo & Vilgalys [as Omphalina ericetorum (Fr.) M. Lange ex H. E. Bigelow], L. hudsoniana (H. S. Jenn.) Redhead, Lutzoni, Moncalvo & Vilgalys [as O. hudsoniana (H. S. Jenn.) H. E. Bigelow], L. velutina (Quél.) Redhead, Lutzoni, Moncalvo & Vilgalys [as O. velutina (Quél.) Quél.] and L. meridionalis (as O. meridionalis), the last being the new combination proposed here. Omphalina meridionalis was originally found in Italy (Contu & La Rocca Reference Contu and La Rocca1999) and the original description has been revised by Barrasa & Esteve-Raventós (Reference Barrasa and Esteve-Raventós2000) to demonstrate the absence of clamps, a feature that characterizes all lichenized species of Lichenomphalia.
Redhead et al. (Reference Redhead, Lutzoni, Moncalvo and Vilgalys2002) considered Omphalina meridionalis to be a probable synonym of L. velutina. However, our previous studies (Barrasa & Esteve-Raventós Reference Barrasa and Esteve-Raventós2000; Barrasa & Rico Reference Barrasa and Rico2001) revealed that both species can be clearly differentiated by their morphological characteristics: mainly fresh basidiomata colours (pileus and lamellae), pigment type of pileipellis and spore shape. We therefore consider L. meridionalis and L. velutina as two different species, with a similar bulbilliferous vegetative thallus, and consequently the new combination L. meridionalis is formally proposed here.
Twenty-one fertile specimens of L. meridionalis (including type material) and eleven of L. velutina from AH, BCC, GDA, IB, LISU and MAF herbaria, have been studied for comparison. The colours of the basidiomata are according to terminology of Munsell (Reference Munsell1994). For comparison of spore shape between taxa, we followed the terminology and corresponding length:breadth ratio (l:b) and mean value (l:b mean) as defined by Bas (Reference Bas1969: 321–322).
Lichenomphalia meridionalis (Contu & La Rocca) Barrasa, Esteve-Rav. & V. J. Rico comb. nov
Omphalina meridionalis Contu & La Rocca, Fungi non Delineati 9: 32–33 (1999) (basionym).—Lichenomphalia meridionalis (Contu & La Rocca) Barrasa & Esteve-Rav. in Esteve-Raventós, Llistosella & Ortega comb. inval., Setas de la Península Ibérica e Islas Baleares: 539 (2007) [Art. 33.2, reference omitted]; type: Italy, Sardinia, Prov. Sassari, M. Limbara, loc. Monte Moroni, zona parafuoco, 10 i 1999, M. Contu (IB 1999/0879—holotype!).
Omphalina hiemalis Barrasa & Esteve-Rav., Book of Abstracts, XIII Congress of European Mycologists: 10 (1999) [inval. ad int.].
(Fig. 1A)
Habit. A, Lichenomphalia meridionalis (AH 32757); B, L. velutina (AH 32758). Scales = 5mm.
Selected descriptions and iconography. Barrasa & Esteve-Raventós (Reference Barrasa and Esteve-Raventós2000: 275 desc., 276–277 icon. (figs. 1–2 and 3–7); sub Omphalina meridionalis); Barrasa & Rico (Reference Barrasa and Rico2001: 379 desc., 380–381 icon., (figs 5–6); sub O. mendionalis); Esteve-Raventós et al. (Reference Esteve-Raventós, Llistosella and Ortega2007: 539 desc. and icon.).
Notes. Molecular studies carried out in lichenized and non-lichenized species of ‘omphalinoid’ agarics, revealed that Lichenomphalia velutina constitutes a complex and variable taxonomic group, in which more than one species can be recognized (Lutzoni Reference Lutzoni1997). Accordingly, Redhead et al. (Reference Redhead, Lutzoni, Moncalvo and Vilgalys2002) recognized L. grisella (P. Karst.) Redhead, Lutzoni, Moncalvo & Vilgalys as a different species from L. velutina, but considered L. meridionalis (sub Omphalina meridionalis) to be a probable synonym of L. velutina. However, Redhead et al. (Reference Redhead, Lutzoni, Moncalvo and Vilgalys2002) indicated that maintaining this synonymy and delimitation of both species remains debatable. A number of names and species with bulbilliferous lichenized thalli (Botrydina type), have been proposed and described: L. grisella, Omphalina rustica (Fr.) Quél, sensu Singer & Clémençon and O. pararustica Clémençon (cf. Singer & Clémençon Reference Singer and Clémençon1972; Clémençon Reference Clémençon1982). All of them are now considered as synonyms of L. velutina, as was already indicated by Barrasa & Rico (Reference Barrasa and Rico2001). Furthermore, the name O. rustica (Fr.) Quél. was also used for non-lichenized species, mainly after Lange (1930). This non-lichenized species [O. rustica (Fr.) Quél. sensu Lange], has been recently transferred to Arrhenia (Redhead et al. Reference Redhead, Lutzoni, Moncalvo and Vilgalys2002).
A number of extra-European lichenized taxa that could not be revised in this work (Omphalina oreades Singer, O. defibulata Singer, Clitocybe borealis Bigelow, C. solumophila Bigelow and C. payattensis Bigelow), have been described from North and South America and included as probable synonyms of Lichenomphalia velutina (Redhead et al. Reference Redhead, Lutzoni, Moncalvo and Vilgalys2002). Moreover, the possibility that one or more of these names takes priority over L. meridionalis cannot be rejected. An exhaustive revision of the type material of all these taxa (including molecular analyses) will be necessary for further studies.
Lichenomphalia meridionalis was described by Contu & La Rocca (Reference Contu and La Rocca1999: 33, tab. XI-B, sub O. meridionalis) as a species with pale ochraceous to weakly-whitish pileus, pure white lamellae and encrusting non-zebroid pileipellis pigments. In agreement with this original description, Barrasa & Rico (Reference Barrasa and Rico2001: 380–381, figs 5–6) clearly distinguish L. meridionalis from L. velutina (Table 1) by its yellowish red, light brown to reddish yellow pileus (Munsell Reference Munsell1994: 5YR5/6, 5YR5/8, 7.5YR6/4, 7.5YR6/6), white lamellae (Munsell Reference Munsell1994: 5YR8/1, 7.5YR8/1) and encrusting non-zebroid pigments of pileipellis hyphae. Lichenomphalia velutina shows a dark grey to grey pileus with brown to light brown tinges (Munsell Reference Munsell1994: N4, N5, N6, 7.5YR4/3, 7.5YR5/3, 7.5YR6/3), dark grey to grey lamellae (Munsell Reference Munsell1994: N4, N5, N6) and an encrusting pigment of pileipellis hyphae forming ‘zebra stripes’. Pigment of pileipellis hyphae is considered a noteworthy character in other groups of agarics [i.e. Entoloma (Fr.) P. Kumm. (Noordeloos Reference Noordeloos1992) and Cortinarius (Pers.) Gray subgenus Telamonia (Fr.) Wünsche (Niskanen Reference Niskanen2008)]. After an exhaustive revision of fresh and herbarium material from the Iberian Peninsula, Barrasa & Rico (Reference Barrasa and Rico2001) observed that several collections with ochraceous pileus and lamellae had been misidentified as L. umbellifera (=O. pseudoandrosacea (Bull.) M. M. Moser), L. velutina or Arrhenia rustica (Fr.) Redhead, Lutzoni, Moncalvo & Vilgalys, and no references to the presence or absence of the lichenized state had been made (see L. meridionalis specimens examined).
Principal characters for distinguishing between Lichenomphalia velutina and L. meridionalis. Pileus and lamellae characters must be observed in fresh basidiomata
In agreement with Lutzoni (Reference Lutzoni1997), L. velutina constitutes a complex taxonomic group, in which more than one species can be differentiated at the molecular level. In the present work, macroscopic differences between L. meridionalis (Fig. 1A) and L. velutina (Fig. 1B) are also emphasized (Table 1), and more collections have been studied for a better diagnosis and delimitation of both species. Therefore, it is very important (as in non-lichenized agarics) to use fertile and fresh material for a correct identification. In this way, basidiomata of L. velutina (particularly lamellae) becomes light-coloured in dry material, causing frequent confusion with L. meridionalis. These macroscopic features together with the microscopic differences observed by Barrasa & Rico (Reference Barrasa and Rico2001), justify the separation of both species and the new combination here proposed for the lichenized species L. meridionalis.
Fresh specimens examined. Lichenomphalia meridionalis [see also Barrasa & Rico (Reference Barrasa and Rico2001: 381–382)]. Spain: Ávila: San Martín del Pimpollar, on acid soil among mosses, 15 v 2004, A. Vargas (AH 37721, sub Omphalina meridionalis). Jaén: Santa Elena, on acid soil with Cistus laurifolius and Quercus ilex, 1 xii 2001, F. Esteve-Raventós (AH 29273, sub O. meridionalis). Segovia: Riaza, La Pinilla, 1443 m, 30TVL6163, on a slope of acid soil among mosses, 16 x 2003, V. J. Rico, J. M. Barrasa & F. Esteve-Raventós (AH 32757, sub O. meridionalis); Riofrío de Riaza, Puerto de la Quesera, 1700 m, 30TVL6264, on a slope among mosses in heath, 26 x 2002, J. M. Barrasa & B. Fano (AH 33747, sub O. meridionalis); Fresno de Cantespino, Prado Pinilla, 1050 m, 30TVL5576, on clayed acid soil in open vegetation of Cistus laurifolius, Quercus ilex and Quercus pyrenaica, 9 xi 2003, J. M. Barrasa (AH 32764, sub O. meridionalis); ibid., 11 x 2003, J. M. Barrasa & B. Fano (AH 32760, sub O. meridionalis).
L. velutina [see also Barrasa & Esteve-Raventós (Reference Barrasa and Esteve-Raventós2000: 278); Barrasa & Rico (Reference Barrasa and Rico2001: 383)]. Spain: Segovia: Riaza, La Pinilla, 1443 m, 30TVL6I63, on a slope of acid soil among mosses, 16 x 2003, V. J. Rico, J. M. Barrasa & F. Esteve-Raventós (AH 32758, sub Lichenomphalia velutina).
We thank Dr M. Contu (Italy) for sending us type material of L. meridionalis. We also thank two anonymous reviewers for critical comments on an earlier version of the manuscript. V. J. R. and J. M. B. acknowledge support from the Spanish Ministerio de Educatión y Ciencia (Flora Liquenológica Ibérica project, CGL2007-66734-C03-01).
