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Amandinea myrticola, a new corticolous species from Portugal

Published online by Cambridge University Press:  05 April 2011

Mireia GIRALT ,
Pieter P.G. van den BOOM  and
John A. ELIX
Mireia GIRALT
Affiliation:
Departament de Bioquímica i Biotecnologia (Àrea de Botànica), Facultat d'Enologia de Tarragona, Universitat Rovira i Virgili, Marcel·lí Domingo s/n, 43007, Tarragona, Spain. Email: mireia.giralt@urv.cat
Pieter P.G. van den BOOM
Affiliation:
Arafura 16, 5691 JA, Son, the Netherlands.
John A. ELIX
Affiliation:
Research School of Chemistry, Building 33, Australian National University, Canberra, ACT 0200, Australia.
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Abstract

Amandinea myrticola is described as new from Portugal. This corticolous species is characterized by the thin, smooth to minutely rugose and greyish thallus lacking secondary metabolites, the small lecideine apothecia which exhibit a pseudothalline margin when young and the small, smooth, Physconia-type ascospores with strongly pronounced and persistent median wall thickenings. It occurs on smooth bark in two localities characterized by a Mediterranean climate with an Atlantic influence.

Keywords

Lecanoromyceteslichenized fungiIberian PeninsulaCaliciaceaetaxonomy

Information

Type
Research Article
Information
The Lichenologist , Volume 43 , Issue 3 , May 2011 , pp. 193 - 197
Copyright
Copyright © British Lichen Society 2011

Introduction

During studies of the genus Buellia s. lat. in the Iberian Peninsula (Giralt et al. Reference Giralt, Barbero and Elix2000a) we examined specimens of an interesting corticolous species, previously identified as Rinodina biloculata (Nyl.) Sheard. Because of its ecological requirements, we were convinced that further material would be located, either during subsequent fieldwork in similar habitats or in herbaria, probably included under other names, possibly as R. pyrina (Ach.) Arnold or R. biloculata. Up to now, no further collections have been found and the specimens are described here as a new species.

Material and Methods

This study was based on herbarium material from the private herbaria of the second author (P. P. G. van den Boom). The specimens were examined by standard techniques using stereoscopic and compound microscopes. Only free ascospores lying outside the asci have been measured and measurements were made at ×1000 magnification on material mounted in water. Mean value (M) and standard deviation (SD) were calculated and the results are given as (minimum value observed) M ± SD (maximum value observed). M, SD and n (the total number of ascospores measured) are given within parentheses. The terminology used for the proper excipulum follows Bungartz et al. (Reference Bungartz, Nordin, Grube, Nash, Ryan, Diederich, Gries and Bungartz2007), for the asci Rambold et al. (Reference Rambold, Mayrhofer and Matzer1994) and for the ascospore-type and their ontogeny Giralt (Reference Giralt2001).

Secondary chemistry was checked by high performance liquid chromatography (HPLC) (Elix et al. Reference Elix, Giralt and Wardlaw2003).

The Species

Amandinea myrticola Giralt, van den Boom & Elix sp. nov

MycoBank no. 518625

Thallus crustaceus, tenuis, griseus, sine substantia metabolica secundaria. Apothecia nigra, lecideina, epruinosa, 0·1–0·3 mm diametro, juvenilia cum margine pseudothallino tenuissimo. Ascosporae typo Physconiae, 11–15 × 4·5–6·5 µm [M = 12·4 × 5·6 µm; SD = 1·3 × 0·5 µm; n = 75], juveniles septo crasso (polariloculares), laeves. Conidia filiformia, ± 20 × 1 µm.

Typus: Portugal, Alentejo, SE of Alvito, S Side of Barragem Odivelas, E of campsite, SW slope with Quercus ilex, Cistus ladanifer, Myrtus communis and pebbles, on Myrtus communis, 100 m, 8°05.6W, 38°10.9′N, 11 July 1995, P. P. G. van den Boom 17189 (GZU—holotypus; BCN & hb. van den Boom—isotypi).

(Figs 1 & 2)

Fig. 1.

Amandinea myrticola (holotype). A, habitus; B, Physconia-type ascospores showing a thick septum and pronounced median wall thickenings [= polarilocular ascospores with long and narrow lumina canals]. Scales: A = 500 µm; B = 10 µm.

Fig. 2.

Amandinea myrticola, ascospore ontogeny and variability (holotype). A, Type-A ontogeny [the septum is inserted before any inner wall thickening has become distinct]; B, immature, hyaline Physconia-type ascospores with median wall thickenings becoming successively more pronounced during development; C, young, slightly pigmented Physconia-type ascospores typically polarilocular with nearly inconspicuous long, very narrow lumina canals; D, mature, brown pigmented, Physconia-type ascospores showing the shorter, thicker lumina canals and the septal pore. Scale = 10 µm.

Thallus corticolous, episubstratal, crustose, continuous, very thin (25–50 µm thick), smooth to minutely rugose, grey, covering large areas (Fig. 1A). Prothallus absent. Medulla not amyloid (I−), lacking calcium oxalate (H2SO4−). Photobiont chlorococcoid, up to 25 µm diam.

Apothecia initially apparently lecanorine, surrounded by a thin and entire pseudothalline margin concolorous with the thallus, becoming lecideine, adnate to sessile, scattered, 0·1–0·2(–3) mm diam. Disc dark brown to blackish, epruinose, plane to convex. Proper margin thin, not persistent. Proper excipulum poorly developed, ± aethalea-type, 20–30 µm wide, prosoplectenchymatous, inner cells elongate, hyaline, outermost cells short, swollen, brown. Hymenium colourless, 50–60 µm high, not inspersed with oil droplets. Hypothecium dark brown, (30–)50–70 µm deep. Paraphyses apical cells 3–5(–6) µm diam., with dark brown cap. Asci 8-spored, Bacidia-type. Ascospores Physconia-type (Figs 1B & 2B–D), (10–)11–13·5(–15) × (4·5–)5–6(–6·5) µm [M = 12·4 × 5·6 µm; SD = 1·3 × 0·5 µm; n = 75], ellipsoid, straight or slightly curved, not constricted at septum, torus absent or poorly developed, outer wall smooth at ×1000. Immature, hyaline ascospores with median wall thickenings becoming successively more pronounced during development (Fig. 2B); young, slightly pigmented ascospores with a thick septum and very pronounced median wall thickenings, typically polarilocular (or placodiomorphic) with nearly inconspicuous long, very narrow lumina canals (or isthmus) (Fig. 2C); mature ascospores with a thinner septum and less pronounced median wall thickenings, with shorter, thicker lumina canals (Fig. 2D). Ascospore-ontogeny of type A (Fig. 2A).

Pycnidia subimmersed, 0·01–0·02 mm diam.; conidiophores type III (Vobis Reference Vobis1980). Conidia filiform, mostly strongly curved, c. 20 × 1 µm.

Chemistry. Thalline and apothecial reactions all negative; no substances detected by HPLC.

Ecology and distribution. At present A. myrticola is known only from the type and one additional locality, both in Alentejo (Portugal). It grows on smooth bark of the twigs of Myrtus communis and Pinus sp., accompanied by typically pioneer, acidophilous species including Amandinea punctata s. lat., Lecanora strobilina (Spreng.) Kieff., L. conizella Nyl., Lecidella elaeochroma (Ach.) M. Choisy and Rinodina freyi H. Magn. Some other taxa present at these localities on another phorophyte (Quercus ilex) included Caloplaca cf. pyracea (Ach.) Th. Fr., C. obscurella (J. Lahm) Th. Fr., Parmotrema reticulatum (Taylor) M. Choisy, Rinodina capensis A. Massal. and Waynea stoechadiana (Abassi & Cl. Roux) P. Clerc & Cl. Roux. Additional species on Cistus ladanifer were Flavoparmelia soredians (Nyl.) Hale, Lecanora albella (Pers.) Ach., L. expallens Ach. and Parmotrema hypoleucinum (J. Steiner) Hale.

Observations. Amandinea myrticola is characterized by the thin, grey thallus lacking secondary metabolites, the small apothecia with a pseudothalline margin when immature and, in particular, by the small, smooth Physconia-type ascospores, which exhibit a thick septum and pronounced median wall thickenings (= typically polarilocular with long and narrow lumina canals) at all ontogenic stages.

Physconia-type ascospores are those that have inner wall thickenings ± pronounced only at the septum (Fig. 2D) and, also occasionally at the apices, although these are rather weak and are only observed briefly during the ascospore development (Giralt Reference Giralt2001). Physconia-type ascospores with a very thick septum and long and narrow lumina canals (= polarilocular, Figs 1B, 2C) have often been called Orcularia-type (e.g. Mayrhofer & Poelt Reference Mayrhofer and Poelt1979, Mayrhofer Reference Mayrhofer1984, Blaha Reference Blaha2002). However, in the strict sense, Orcularia-type ascospores follow a different ontogeny from the Physconia-type and, hitherto, have only been observed in taxa of section Orcularia Malme, for example Rinodina biloculata. Malme (Reference Malme1902) segregated these species from other sections of Rinodina because of their polarilocular ascospores and the brown hypothecium (cf. Sheard Reference Sheard1967). In ascospores with Physconia-type ontogeny, the septum is inserted before any inner wall thickening appears (Fig. 2A), whereas in Orcularia-type ascospores, the septum is inserted after lateral inner wall thickenings become distinct (compare the Orcularia-type ascospore-ontogeny of R. biloculata in Giralt & Matzer Reference Giralt and Matzer1994, fig. 2C: 322; Giavarini et al. Reference Giavarini, James, Purvis, Smith, Aptroot, Coppins, Fletcher, Gilbert, James and Wolseley2009, fig. 47: 814; and of Amandinea insperata (Nyl.) H. Mayrhofer & Ropin in Marbach Reference Marbach2000, Abb. 25: 79). Consequently, immature uniseptate ascospores with pronounced lateral thickenings (with a single lumina ± bone-shaped) are common and very characteristic in the Orcularia-type but absent in the Physconia-type.

Because of their polarilocular ascospores, the specimens of Amandinea myrticola were identified as Rinodina biloculata, with Orcularia-type ascospores. Apart from the different ascospore-type, R. biloculata can easily be separated from A. myrticola by the larger ascospores, of 12–18 × 7–10 µm, which are ± citriform in shape and, according to Giavarini et al. (Reference Giavarini, James, Purvis, Smith, Aptroot, Coppins, Fletcher, Gilbert, James and Wolseley2009), the bacilliform conidia.

Amandinea myrticola can also be mistaken for Rinodina pyrina but this species has larger and typically lecanorine apothecia, a colourless hypothecium, Lecanora-type asci and bacilliform conidia.

Other corticolous Amandinea species present in the area included the polymorphic A. punctata s. lat. and A. crassiuscula Giralt & Etayo. Both are distinguished from A. myrticola by the larger Buellia-type, ascospores (Scheidegger Reference Scheidegger1993; Bungartz et al. Reference Bungartz, Nordin, Grube, Nash, Ryan, Diederich, Gries and Bungartz2007). Further, A. crassiuscula has strongly ornamented ascospores and a thickly crustose to subsquamulose thallus (Giralt et al. Reference Giralt, Etayo and Gómez-Bolea2000b). According to Sheard & May (Reference Sheard and May1997), Marbach (Reference Marbach2000), Blaha (Reference Blaha2002), Hafellner (Reference Hafellner2004) and Bungartz et al. (Reference Bungartz, Nordin, Grube, Nash, Ryan, Diederich, Gries and Bungartz2007), there are no other species of Amandinea morphologically similar to A. myrticola.

Additional specimen examined. Portugal: Alentejo: SSW of Évora, SE of Alvito, S side of Barragem Odivelas; valley W of dam, various trees along small fen (young Fraxinus, Pinus, Salix), on Pinus twig, 75 m, 8°06.9′W, 38°11.0′N, 10 July 1995, P. P. G. van den Boom 17152 (hb. van den Boom).

The first author is grateful for funding of project CGL2007-66734-C03-02/BOS by the Spanish Government. We thank Harrie Sipman for assistance with the Latin diagnosis.

References

Blaha, J. (2002) Taxonomische Studien an saxicolen Arten der Flechtengattung Amandinea (lichenisierte Ascomyceten, Physciaceae) von Neuseeland. Diplomarbeit, Karl-Franzens-Universität Graz.Google Scholar
Bungartz, F., Nordin, A. & Grube, U. (2007) Buellia De Not. In Lichen Flora of the Greater Sonoran Desert Region Volume 3 (Nash, T. H. III, Ryan, B. D., Diederich, P., Gries, C. & Bungartz, F., eds): 113–179. Tempe, AZ: Lichens Unlimited.Google Scholar
Elix, J. A., Giralt, M. & Wardlaw, J. H. (2003) New chloro-depsides from the lichen Dimelaena radiata. Bibliotheca Lichenologica 86: 1–7.Google Scholar
Giavarini, V., James, J. W. & Purvis, O. W. (2009) Rinodina (Ach.) Gray (1821). In The Lichens of Great Britain and Ireland. (Smith, C. W., Aptroot, A., Coppins, B. J., Fletcher, A., Gilbert, O. L., James, P. W. & Wolseley, P. A., eds): 812–825. London: British Lichen Society.Google Scholar
Giralt, M. (2001) The lichen genera Rinodina and Rinodinella (lichenized Ascomycetes, Physciaceae) in the Iberian Peninsula. Bibliotheca Lichenologica 79: 1–160.Google Scholar
Giralt, M. & Matzer, M. (1994) The corticolous species of the genus Rinodina with biatorine or lecideine apothecia in southern Europe and Macaronesia. Lichenologist 26: 319–332.CrossRefGoogle Scholar
Giralt, M., Barbero, M. & Elix, J. A. (2000a) Notes on some corticolous and lignicolous Buellia species from the Iberian Peninsula. Lichenologist 32: 105–128.CrossRefGoogle Scholar
Giralt, M., Etayo, J. & Gómez-Bolea, A. (2000b) Amandinea crassiuscula, a new corticolous species from the Iberian Peninsula. Lichenologist 32: 521–529.CrossRefGoogle Scholar
Hafellner, J. (2004) A further evolutionary lineage to lichenicolous growth in Physciaceae (Lecanorales). Bibliotheca Lichenologica 88: 175–186.Google Scholar
Malme, G. O. (1902) Die Flechten der ersten Regnellschen Expedition II. Die Gattung Rinodina (Ach.) Stiz. Bihang till Kongliga Svenska Vetenskaps-Akademiens Handlingar 28 (3/1): 1–53.Google Scholar
Marbach, B. (2000) Corticole und lignicole Arten der Flechtengattung Buellia sensu lato in den Subtropen und Tropen. Bibliotheca Lichenologica 74: 1–384.Google Scholar
Mayrhofer, H. (1984) Die saxicolen Arten der Flechtengattung Rinodina und Rinodinella in der Alten Welt. Journal of the Hattori Botanical Laboratory 55: 327–493.Google Scholar
Mayrhofer, H. & Poelt, J. (1979) Die saxicolen Arten der Flechtengattung Rinodina in Europa. Bibliotheca Lichenologica 12: 1–186.Google Scholar
Rambold, G., Mayrhofer, H. & Matzer, M. (1994) On the ascus types in the Physciaceae (Lecanorales). Plant Systematics and Evolution 192: 31–40.CrossRefGoogle Scholar
Scheidegger, C. (1993) A revision of European saxicolous species of the genus Buellia De Not and formerly included genera. Lichenologist 25: 315–364.CrossRefGoogle Scholar
Sheard, J. W. (1967) A revision of the lichen genus Rinodina (Ach.) Gray in the British Islands. Lichenologist 3: 328–367.CrossRefGoogle Scholar
Sheard, J. W. & May, P. F. (1997) A synopsis of the species of Amandinea (lichenized Ascomycetes, Physciaceae) as presently known in North America. Bryologist 100: 159–169.CrossRefGoogle Scholar
Vobis, G. (1980) Bau und Entwicklung der Flechten-Pycnidien und ihrer Conidien. Bibliotheca Lichenologica 14: 1–141 +Abb.Google Scholar
Figure 0

Fig. 1. Amandinea myrticola (holotype). A, habitus; B, Physconia-type ascospores showing a thick septum and pronounced median wall thickenings [= polarilocular ascospores with long and narrow lumina canals]. Scales: A = 500 µm; B = 10 µm.

Figure 1

Fig. 2. Amandinea myrticola, ascospore ontogeny and variability (holotype). A, Type-A ontogeny [the septum is inserted before any inner wall thickening has become distinct]; B, immature, hyaline Physconia-type ascospores with median wall thickenings becoming successively more pronounced during development; C, young, slightly pigmented Physconia-type ascospores typically polarilocular with nearly inconspicuous long, very narrow lumina canals; D, mature, brown pigmented, Physconia-type ascospores showing the shorter, thicker lumina canals and the septal pore. Scale = 10 µm.