Lecanora dispersa (Pers.) Sommerf

Suppl. Fl. Lapp. 1826: 96 (1826).—Lichen dispersus Pers., Neue Ann. Bot. 1 [Ann. Bot. 7]: 27 (1794); type: Germany, Mitteldeutschland, Bez. Nordhessen: kleinflächig an licht- und windoffenen, aber teilweise regengeschützten Stirn- und Uberhangflächen stark ausgearbeiteter Dolomitfelsen im Caloplacetum saxicolae Du Rietz, 300 m, SO-SW, pH 7·5 naturnaher Trockenrasen auf dem Höhenzug in der Werraschleife von Albungen südlich Hitzerode, April 1977, Follmann & Folmann (MIN 760355!—neotype).

(Fig. 1A)

Fig. 1.

The Lecanora dispersa group in Argentina, habit. A, L. dispersa [Messuti, Ferraro & Vobis (BCRU 4813)]; B, L. flowersiana [Räsänen (MERL 5969)]; C, L. aff. fugiens [Messuti (BCRU 5227)]; D, L. hagenii [Messuti (BCRU 5212)]; E, L. persimilis [Guderley, Lumbsch & Vobis (BCRU 5233)]; F, L. semipallida [de la Rosa & Barbar (BCRU 5211)]. Scales: A–F = 1 mm.

Thallus not visible, immersed in the substratum, or poorly developed, inconspicuous, crustose, comprised of small scattered warts, rarely continuous, smooth to rough, thin, whitish to chestnut-brown.

Apothecia lecanorine, disciform, sessile, constricted at the base, occurring singly, rarely clustered in groups, 0·3–1·0 (–1·2) mm diam.; disc flat to slightly convex, reddish brown to almost black, epruinose to moderately pruinose; margin well-developed, conspicuous, prominent or level with the disc, entire to rarely slightly fissured, frequently flexuose, smooth to rough, white to greyish, covered by a dense white pruina. Amphithecium well-developed, (40–) 60–200 µm wide; algal layer continuous to ±interrupted below hypothecium; cortex distinct, hyaline to pale brownish, gelatinous, uniform in thickness to slightly thicker at base, 15–35 µm thick laterally, 40–75 µm thick basally, with granules (pol+), insoluble in K and soluble in N; parathecium indistinct, hyaline, prosoplectenchymatous, 12–25 µm thick; epihymenium brownish to yellowish brown, 5–25 µm high, with granules (pol+), insoluble in K, insoluble in N; epipsamma rarely present, insoluble in K, soluble in N; hymenium hyaline to brownish, 40–75 µm high, with small granules (pol+); subhymenium inconspicuous; hypothecium hyaline, gelatinous, 50–200 µm high; paraphyses simple, rarely branched, not anastomosed, c. 2 µm wide, tips not expanded to rarely dilated without a dark brown cap, 2·5–3 µm wide. Asci cylindrical to clavate, 8-spored; ascospores hyaline, simple, ellipsoid to oblong, rarely spindle-shaped, 8·9–12·0 (–13) × (3·0–) 4·0–5·7 (–6·5) µm.

Pycnidia not seen.

Chemistry. Apothecia K−, C−, PD−, UV−. Secondary metabolites: 2,7-dichlorolichexanthone, pannarin; or no secondary metabolites detected by HPTLC.

Ecology and distribution. Lecanora dispersa is a common species occurring on a wide range of substrata, including calcareous and siliceous rocks, bark, bones, and many man-made substrata. This species has a cosmopolitan distribution, and is known from all continents (Lindsay Reference Lindsay1974; Poelt et al. Reference Poelt, Leuckert and Roux1995; Śliwa & Olech Reference Śliwa and Olech2002; Ryan et al. Reference Ryan, Lumbsch, Messuti, Printzen, Śliwa, Nash, Nash, Ryan, Gries and Bungartz2004; Śliwa Reference Śliwa2006, Reference Śliwa2007a; Edwards et al. Reference Edwards, Aptroot, Hawksworth, James, Smith, Aptroot, Coppins, Flechter, Gilbert, James and Wolseley2009; van den Boom Reference van den Boom2010a). In Argentina, it has been previously reported on mortar, concrete, rocks and soil in the urbanized areas of Buenos Aires province and in the Patagonian steppe of Chubut province (Scutari et al. Reference Scutari, Doris Diez and Lumbsch2002; Rosato Reference Rosato2006). The distribution of L. dispersa within Argentina is extended for Neuquén, Río Negro and Tierra del Fuego provinces.

Remarks. Lecanora dispersa is characterized by having fine epihymenial granules (pol+) between the paraphyses tips, and also interspersed in parts or all of the hymenium, insoluble in K and insoluble in N. Externally it can easily be confused with L. hagenii, because both species have reddish to blackish brown apothecia, with epruinose to slightly pruinose discs, and entire to cracked margins (Laundon Reference Laundon2003). Nevertheless, L. hagenii differs anatomically from L. dispersa by a thinner and regular apothecial margin, and epihymenial granules (pol±) that are insoluble in K, soluble in N, and occur only at the top of the hymenium. The paraphyses of L. hagenii are also simple, thicker and apically expanded, and the spores are slightly larger (9–15 × 5–7 µm) (Ryan et al. Reference Ryan, Lumbsch, Messuti, Printzen, Śliwa, Nash, Nash, Ryan, Gries and Bungartz2004; Śliwa Reference Śliwa2006, Reference Śliwa2007a). Lecanora dispersa is chemically similar to L. albescens: both contain 2,7-dichlorolichexanthone and ±pannarin. However, L. albescens has a well-developed thallus, often lobate at the margin, with generally pruinose apothecia. Another similar species is L. semipallida, which has UV+ yellow-orange apothecia (due to the presence of 5-chloro-3-O-methylnorlichexanthone) and epihymenial granules that are soluble in K and located only in the uppermost part of the hymenium (Śliwa Reference Śliwa2006, Reference Śliwa2007a, b). Comparing the North American material examined by Ryan et al. (Reference Ryan, Lumbsch, Messuti, Printzen, Śliwa, Nash, Nash, Ryan, Gries and Bungartz2004) and Śliwa (Reference Śliwa2007a) with the Argentinean specimens, it was noted that the latter have a thinner amphithecial cortex (15–35 µm thick laterally, 40–75 µm thick basally versus 30–80 µm thick laterally, 35–120 µm thick basally in North American material).

Specimens examined. Argentina: Neuquén: estancia Arroyo Verde, a 70 km de San Carlos de Bariloche, camino a Villa Traful, ñirantal cerca de corral, junto a la manga, 26 ix 2010, Messuti (BCRU 5213). Río Negro: Pilcaniyeu, estancia San Ramón, 8 xii 1992, Messuti (BCRU 5214); San Carlos de Bariloche, barrio Jardín Botánico, calle Las Orquídeas 1243, 6 i 2011, Vobis (BCRU 5226); Elordi y Mitre, 21 xii 1992, Messuti (BCRU 4812). Chubut: ruta nac. 25, camino a Tecka, c. 12 km de Esquel, 42°58′08″S, 71°09′53″W, 770 m alt., 28 ii 2010, de la Rosa (BCRU 5216). Tierra del Fuego, Antártida e Islas del Atlántico Sur: Ushuaia, río Pipo, frente al campo Monseñor Alemán, sobre la ladera que mira al N, zona muy alberta, con renovales de lenga, Monte Susana, 11 iii 1995, Messuti, Ferraro & Vobis (BCRU 4813).

Lecanora flowersiana H. Magn

Acta Horti Gotob. 19(2): 38 (1952); type: USA, Utah, Wayne Co., Ekkers Ranch, on dry exposed sandstone, at 6000 ft., 19 May 1951, Flowers (COLO L–80895!—isotype).

(Fig. 1B)

Thallus immersed in the substratum, sometimes superficial, poorly developed, inconspicuous, crustose, consisting of irregular warts, more frequent around the apothecia, whitish beige, brown or grey, mingled with the substratum (rock).

Apothecia lecanorine, disciform, sessile, constricted at the base, numerous, clustered in groups, irregular when grouped, 0·6–1·3 mm diam.; disc concave to plane-concave, brown, reddish brown to pale reddish brown, occasionally black, epruinose, rarely covered by a small white pruina; margin well-developed, ±prominent, incised, with deep cracks, strongly flexuous in larger ascomata, white, sometimes pruinose with a bluish tinge. Amphithecium well-developed, 50–200 µm wide; algal layer conspicuous, dense, ±continuous; cortex poorly defined, prosoplectenchymatous, hyphae with strongly gelatinized walls, uniform in thickness, 20–80 µm thick, filled with granules (pol+), insoluble in K, soluble in N; parathecium inconspicuous, hyaline, prosoplectenchymatous, without crystals (pol−), 25–40 µm thick; epihymenium ±deeply pigmented or pigment only in the upper part of the hymenium, reddish to reddish brown, sometimes pale brownish, 5–12·5 µm high, not granular (pol−) or with inconspicuous granules (pol+); epipsamma present (pol+), insoluble in K, soluble in N; hymenium brownish at upper part, hyaline below, with oil droplets, 40–75 µm high; subhymenium hyaline, granular; hypothecium hyaline to brownish, prosoplectenchymatous, gelatinous, 12–25 µm high, granules present or absent (pol±); paraphyses branched in the upper third, c. 1·5 µm wide, tips furcated, slightly expanded (submoniliform), with or without dark cap, 1·5– 2·5 µm wide. Asci clavate, 8-spored; ascospores hyaline, simple, ellipsoid, broadly ellipsoid to narrowly ellipsoid, 8·0–10·5 × 4·0–5·7 µm.

Pycnidia not seen.

Chemistry. Apothecial margin K−, C−, KC−, PD−, UV−. No secondary metabolites detected by HPTLC.

Ecology and distribution. This species grows on sandstone, granite and sporadically on wood, in desert to montane habitats, at elevations from 1000 to 2800 m, in central and western North America (Śliwa Reference Śliwa2007a). Recently it has also been recorded from Iran, growing on bark (Valadbeigi & Sipman Reference Valadbeigi and Sipman2010), and also from the Canary Islands (van den Boom Reference van den Boom2010b). In Argentina, L. flowersiana has been found on calcareous rocks, between 800–900 m a.s.l, in the lower montane region of Mendoza province (Las Heras). This is the first record of the species in South America.

Remarks. The diagnostic characters for L. flowersiana are: apothecial discs reddish brown, margin cracked, often flexuose, cortex uniform in thickness, epihymenium pigmented deeper down, generally not at all granular (pol−) and paraphyses submoniliform with pigmented tips. Lecanora percrenata H. Magn. is a closely related species which has a markedly cracked apothecial margin, but differs in having apothecia submersed in the substratum, with a more prominent and fissured margin and brown to blackish discs. The collection from MERL has been previously recognized as L. crenulata by Räsänen (Reference Räsänen1941), but this species is distinguished by its pruinose apothecia, cracked to crenate margin, well defined cortex, distinct parathecium and yellowish brown to brownish epihymenium. The Argentinean specimens are similar to North American material in most apothecial characters (Ryan et al. Reference Ryan, Lumbsch, Messuti, Printzen, Śliwa, Nash, Nash, Ryan, Gries and Bungartz2004; Śliwa Reference Śliwa2007a), but differ in having a prosoplechtenchymatous amphithecial cortex and a thinner hypothecium (15–25 µm high versus 50–90 µm high).

Specimens examined. Argentina: Mendoza: Las Heras, Cerro de la Gloria, 18 vi 1939, Räsänen (MERL 5969); ibid., 20 xi 1996, Vobis & Messuti (BCRU 5215); reserva natural Divisadero Largo, ruinas mina quebrada la Atala, c. 10 km westl. Mendoza, offene Buschlandschaft, 35°52′S, 68°55′W, c. 1000 m alt., 19 xi 1997, Guderley & Guinazu [hb. Ruhr Museum (ex Guderley) 159].

Lecanora aff. fugiens Nyl

(Fig. 1C)

Thallus developed within the substratum to superficial, inconspicuous, crustose, ± continuous, very thin, membranous, smooth, and whitish.

Apothecia lecanorine, disciform, regular, sessile, constricted at base, single, 0·3–0·5 mm diam.; disc flat to slightly convex, brown with orange tint to reddish brown, dark brown to blackish, epruinose to moderately pruinose; margin prominent, smooth, entire, rarely incised in young apothecia, white, epruinose to slightly pruinose. Amphithecium well-developed, 90–130 µm wide; algae scattered in groups to continuous below the hypothecium; cortex well differentiated, hyaline, composed of agglutinated hyphae, strongly gelatinized, uniform in thickness to thicker at base, 10–25 µm thick laterally, 40–70 µm thick basally, with granules (pol+) only in the upper part, partially soluble in K, soluble in N; parathecium inconspicuous, hyaline, gelatinous, without crystals (pol−), 20–25 µm thick; epihymenium brown to greyish brown, 7·5–12·5 µm high, with coarse granules (pol+), on the top and between the paraphyses tips, insoluble in K, soluble in N; epipsamma rarely present (pol+), indistinct, insoluble in K, soluble in N; hymenium hyaline to pale brownish, 100–130 µm high; subhymenium and hypothecium poorly differentiated, hyaline, paler than hymenium, 12·5–50·0 µm high; paraphyses furcate in the uppermost part, 1–2 µm wide, tips often expanded, c. 3 µm wide. Asci clavate, 8-spored; ascospores hyaline, simple, ellipsoid to broadly ellipsoid, 8·1–10·5 × 4·9–6·5 µm.

Pycnidia not seen.

Chemistry. Thallus and apothecial margin K−, C−, PD–; disc K−, C−, PD−; apothecia UV± yellowish. Apothecial disc in section PD+ orange. Secondary metabolites detected by HPTLC: pannarin, unknown substance [In solvent A: Rf _{unknown substance} = 26/ Rf _N = 58, Rf _A = 77 (A: atranorin, N: norstictic acid), spot yellowish after charring].

Ecology and distribution. Lecanora fugiens grows on rocks in temperate oceanic regions of North America and northern Europe (Śliwa Reference Śliwa2007a; Edwards et al. Reference Edwards, Aptroot, Hawksworth, James, Smith, Aptroot, Coppins, Flechter, Gilbert, James and Wolseley2009). Hitherto this species has not been reported for South America. The single collection of Lecanora aff. fugiens from Argentina was made from the bark of a thorny bush (Berberis buxifolia Lam.) in the transitional forest in Río Negro province.

Remarks. The specimen from Argentina is distinguished by its visible thallus, small, single apothecia, with a rather pale disc, a distinct amphithecial cortex and a PD+ orange epihymenium. Lecanora fugiens shows a similar PD± orange reaction in the apothecial disc, but has an evanescent to crustose thallus, a white dendroid prothallus, K+ yellow and C+ orange reactions of thallus and apothecia, and occurs on siliceous rocks. The species also differs by its amphithecial cortex being thinner at the base (30–45 µm), and having an epihymenium with granules soluble in K (Śliwa Reference Śliwa2007a). The Argentinean material studied is also morphologically similar to L. hagenii, because of the small, single, brown to reddish brown apothecia. However, L. hagenii has an endophloeodal or endolithic thallus, and an indistinctly granular epihymenium, which is PD−. Our understanding of this taxon and its relationship to the L. dispersa group is still incomplete since only one specimen was found.

Specimen examined. Argentina: Río Negro: San Carlos de Bariloche, Pampa de Huenuleo, 25 ii 1992, Messuti (BCRU 5227).

Lecanora hagenii (Ach.) Ach

Lichenogr. Universalis 1810: 367 (1810).—Lichen hagenii Ach. nom. cons., Lichenogr. Suec. Prodr. 1799: 57 (1799); type: Germany, An einem alten Brette der Hofeinfassung des Linderl–Anwesens in Nymphenburg. München, 27 October 1889, Arnold (M 0035420!—conserved type).

(Fig. 1D)

Thallus developed within the substratum, rarely superficial, crustose, inconspicuous, thin, whitish grey to brownish.

Apothecia lecanorine, disciform, broadly sessile, single to ±grouped, 0·3–0·9 mm diam.; disc flat to slightly convex, concave to flat in young apothecia, yellowish brown, reddish, orange-brown, dark brown to blackish, epruinose to moderately whitish pruinose; margin prominent to level with disc, smooth to rough, entire or more often partly discontinuous, white, paler than disc, rarely greyish, epruinose or covered by a thick, whitish pruina. Amphithecium well-developed, 75–150 µm wide; algal layer dense, continuous below the hypothecium; cortex poorly differentiated to distinct, hyaline, formed by hyphae with gelatinized walls, prosoplectenchymatous, uniform in thickness to slightly thicker at base, 10–25 µm thick laterally, 20–25 µm thick basally , with granules (pol+), often more abundant on top of margin, insoluble in K, soluble in N; parathecium inconspicuous, hyaline, without granules (pol−), 25–50 µm thick; epihymenium brownish to dark brown, frequently reddish brown, 5·0–12·5 µm high, with inconspicuous granules (pol±), coarse, on the top and between the paraphyses tips, insoluble in K, soluble in N, or granules absent; epipsamma present (pol+), insoluble in K, soluble in N; hymenium hyaline, 50–75 µm high; subhymenium indistinct; hypothecium hyaline, composed of agglutinated hyphae, 40–60 µm high; paraphyses branched, frequently furcated in the uppermost part, c. 2 µm wide, tips dilated, with dark brown cap, c. 3 µm wide. Asci clavate, 8-spored; ascospores hyaline, simple, ellipsoid, broadly to narrowly ellipsoid, 8·9–14·6 × 4·8–7·3 µm.

Pycnidia not seen.

Chemistry. Apothecia K−, C−, PD−, UV−. No secondary metabolites detected by HPTLC.

Ecology and distribution. Lecanora hagenii grows generally on bark, wood, bryophytes, bones, and on other organic substrata, and less commonly on rocks. It is widespread in temperate regions of Europe, North America and Asia (Poelt et al. Reference Poelt, Leuckert and Roux1995; Ryan et al. Reference Ryan, Lumbsch, Messuti, Printzen, Śliwa, Nash, Nash, Ryan, Gries and Bungartz2004; Śliwa Reference Śliwa2007a; Edwards et al. Reference Edwards, Aptroot, Hawksworth, James, Smith, Aptroot, Coppins, Flechter, Gilbert, James and Wolseley2009). In Argentina it has been found previously on calcareous rocks and mortar in various urban environments in Buenos Aires province and the Magellan steppe region of Tierra del Fuego province [Cengia Sambo Reference Cengia Sambo1926; Rosato Reference Rosato2006, under the synonym L. umbrina (Ach.) A. Massal.]. Lecanora hagenii is here reported for the first time in Neuquén and Río Negro provinces.

Remarks. Lecanora hagenii is characterized by its slightly cracked apothecial margin and indistinct amphithecial cortex. Lecanora hagenii resembles L. dispersa, but the differences are discussed under the latter species. Lecanora wetmorei Śliwa has similar pruinose apothecial discs, but has larger apothecia [0·4–1·2 (–1·5) mm diam.], with an entire to flexuose margin, reddish brown to black discs, and thicker cortex at the base (60–100 µm). Lecanora hagenii may also be confused with L. crenulata Hook. However, the latter species differs by having a distinctly cracked to crenate apothecial margin and a cortex that is thicker at the base (30–70 µm wide laterally, 50–130 µm basally). Moreover, L. crenulata grows exclusively on calcareous rocks (Ryan et al. Reference Ryan, Lumbsch, Messuti, Printzen, Śliwa, Nash, Nash, Ryan, Gries and Bungartz2004; Śliwa Reference Śliwa2007a). The Argentinean specimens examined have a slightly thicker amphithecium (75–150 µm thick versus 75–90 µm thick), but in all other respects the morphological and anatomical characters of this material agreed with the variation accepted for the species in North America and Europe (Ryan et al. Reference Ryan, Lumbsch, Messuti, Printzen, Śliwa, Nash, Nash, Ryan, Gries and Bungartz2004; Śliwa Reference Śliwa2007a; Edwards et al. Reference Edwards, Aptroot, Hawksworth, James, Smith, Aptroot, Coppins, Flechter, Gilbert, James and Wolseley2009).

Specimens examined. Argentina: Neuquén: ruta Confluencia-Traful, en dirección a Paso Córdoba, estancia Arroyo Verde, cercanías a la manga, 3 v 2007, Messuti (BCRU 5204); junto al río Limay, puente de la ruta 237, cercanías al Boliche Viejo, iv 1994, Messuti (BCRU 5212). Río Negro: San Carlos de Bariloche, cerro Otto, camino a la curva Bariloche, 17 xi 2007, de la Rosa (BCRU 5210); balneario Las Grutas, en dirección a San Antonio Oeste, pasando bajada La Rinconada, zona de matorral cerca de la costa del mar, 40°47′35″S, 65°03′26″W, c. 7 m alt., 2 i 2010, de la Rosa & Moreno Azócar (BCRU 5209). Tierra del Fuego, Antártida e Islas del Atlántico Sur: estancia San Luis, a 40 km de Río Grande, cerca de la costa del océano Atlántico, entre Punta María y estancia Viamonte, 14 iii 1995, Vobis (BCRU 4814); Lapataia, lago Roca, en el bosque cerca de sendero, cerca de la costa, 12 iii 1995, Vobis (BCRU 5219).

Lecanora persimilis (Th. Fr.) Nyl

Flora 59: 577 (1876).—Lecanora hagenii [subsp.] persimilis Th. Fr. Lichenogr. Scand. 1: 251–252 (1871); type: Sweden, Westrogothie: Kållandsö, på ask, 1861, Graewe (UPS—lectotype, non vidi).

(Fig. 1E)

Thallus developed within the substratum, rarely on the surface, scattered in patches, smooth, membranous, whitish to frequently grey.

Apothecia lecanorine, sometimes biatorine in appearance, disciform, rounded, broadly sessile, usually single, dispersed throughout the thallus, 0·2–0·5 mm diam.; disc flat, epruinose, brown to dark brown, often glossy; margin prominent, entire, rarely with some radial fissures, smooth, epruinose, concolorous with disc. Amphithecium ±developed, 40–90 µm wide, algae more abundant near the base, forming a loose, discontinuous algal layer, without crystals (pol−); cortex distinct, hyaline to reddish brown, prosoplectenchymatous, hyphae with pigmented ends, reddish-brown, covered externally by a gelatinous layer, slightly thicker at the base, 12–25 µm thick laterally, 25–35 µm thick basally, with granules (pol+), insoluble to partly soluble in K, soluble in N; parathecium distinct, hyaline, prosoplectenchymatous, reddish brown at the upper part, 12·5–25 µm thick; epihymenium reddish brown, 5–15 µm high, without granules (pol−), pigment slightly altered in K, turning brown; epipsamma absent; hymenium hyaline to pale brownish, 35–50 µm high; subhymenium and hypothecium hyaline, 50–75 µm high; paraphyses simple, free, c. 1 µm wide, tips expanded and pigmented, c. 3 µm wide. Asci clavate, 8-spored; ascospores hyaline, simple, narrowly ellipsoid to ellipsoid, more rarely widely ellipsoid, 10·5–14·0 (–15·4) × 4·0– 5·7 µm.

Pycnidia not seen.

Chemistry. Apothecia K− yellow, C−, KC−, PD− orange-yellow. No secondary metabolites detected by HPTLC.

Ecology and distribution. This species belongs to the boreal and mainly temperate regions, found on the bark of branches and twigs of deciduous trees. It is known from Europe and North America (Śliwa Reference Śliwa2007a; Edwards et al. Reference Edwards, Aptroot, Hawksworth, James, Smith, Aptroot, Coppins, Flechter, Gilbert, James and Wolseley2009). The specimen examined here was collected on wood from Andean Patagonian Nothofagus forest in Tierra del Fuego province. This is the first record of the species in South America.

Remarks. The combination of endophloeodal thallus, and small chocolate-brown, epruinose apothecia, frequently with a biatorine appearance, is characteristic of L. persimilis. Unfortunately the lectotype was not available in the herbarium (UPS) during this study. The similar species Lecanora sambuci (Pers.) Nyl. is distinguished by the apothecia being slightly immersed in the substratum and having multispored asci (Śliwa Reference Śliwa2007a). Lecanora persimilis also resembles L. hagenii by its epruinose apothecia, but the latter species has an apothecial margin that is paler than the disc or whitish, and a well-developed amphithecium with a thick, dense algal layer. The Argentinean material presents the same morphological and anatomical characters as reported from the North American and European specimens (Ryan et al. Reference Ryan, Lumbsch, Messuti, Printzen, Śliwa, Nash, Nash, Ryan, Gries and Bungartz2004; Śliwa Reference Śliwa2007a; Edwards et al. Reference Edwards, Aptroot, Hawksworth, James, Smith, Aptroot, Coppins, Flechter, Gilbert, James and Wolseley2009), but differs in having a thinner amphithecial cortex at the base (25–35 µm thick versus 20–69 µm thick).

Specimens examined. Argentina: Tierra del Fuego, Antártida e Islas del Atlántico Sur: Parque Nacional Tierra del Fuego, bahía Ensenada, c. 15 km W von Ushuaia, exponierte Künstenfelsen, 54°50′S, 67°28′W, 8 xi 1997, Guderley, Lumbsch & Vobis (BCRU 5233).

Lecanora semipallida H. Magn

In Hedin, S. (ed.), Lichens from Central Asia I, Reports Scientific Exped. North-west. Provinces of China (the Sino-Swedish expedition). 13, XI Botany, 1. Aktiebolaget, Thule & Stockholm: 89 (1940); type: China, China occidentalis, prov. Kansu: Wai-chüan-ku, E abYeh-ma-ta-chüan, c. 3000 m.s.m., 13 December 1931, Bohlin (S L3745!—holotype).

(Fig. 1F)

Thallus developed within the substratum, rarely visible, crustose, inconspicuous, thin, smooth to rough, ± granular, greenish grey to pale grey.

Apothecia lecanorine, disciform, sessile, single, 0·3–0·9 mm diam.; disc flat, concave when immature, rarely convex, epruinose, brownish, yellow to yellowish brown; margin prominent to level with the disc, smooth, sometimes crenate, rarely flexuose, yellowish white to grey, brownish, covered by whitish pruina. Amphithecium well-developed, 100–150 µm wide, algal layer dense, continuous; cortex distinct, hyaline, prosoplectenchymatous, thicker at base, 35–70 µm thick laterally, 80–180 µm thick basally, with granules (pol+), insoluble in K, and soluble in N; parathecium hyaline, conspicuous, without crystals (pol−), 20–40 µm thick; epihymenium yellowish brown to dark brown, 20–30 µm high, granular (pol+), granules soluble in K, insoluble in N; epipsamma absent; hymenium hyaline, 50–70 µm high; subhymenium and hypothecium hyaline, 25–75 µm high; paraphyses 1·0–1·5 µm wide, with slightly expanded and furcate tips, c. 3 µm wide. Asci clavate, 8-spored; ascospores hyaline, simple, ellipsoid, 8·9–14·6 × 4·8–7·3 µm.

Pycnidia not seen.

Chemistry. Apothecia K−, C−, PD−, UV+ orange. Secondary metabolites detected by HPTLC: vinetorin (5-chloro-3-O-methylnorlichexanthone).

Ecology and distribution. Lecanora semipallida is a saxicolous species, found on calcareous rocks, concrete, or growing on other lichens, but occasionally occurs on bark, bryophytes, plant debris and metals. It is widely distributed in Europe and North America, Asia, Australia and New Zealand (Śliwa Reference Śliwa2007a, b; Edwards et al. Reference Edwards, Aptroot, Hawksworth, James, Smith, Aptroot, Coppins, Flechter, Gilbert, James and Wolseley2009). Most recently it has been noted also from Peru (see Śliwa et al., in press). In Argentina it is found on bones and calcareous rocks in the provinces of Río Negro and Tierra del Fuego. This is the first record for the species in Argentina.

Remarks. Lecanora semipallida is easily recognized by its immersed thallus, the apothecia being yellowish, occurring singly, with a UV+ bright orange to pale orange reaction, and by the presence of vinetorin. It is superficially similar to L. dispersa, but it can be distinguished by the solubility of the epihymenial granules and by the chemistry (see under the latter species). The two collections studied here exhibit the expected anatomy of the species (Lumbsch & Elix Reference Lumbsch, Elix, McCarthy and Mallett2004; Śliwa Reference Śliwa2007a, b), but had a significantly thicker amphithecial cortex (up to 180 µm), and asci that were constantly 8-spored.

Specimen examined. Argentina: Río Negro: San Carlos de Bariloche, cerro Tronador, Ventisquero Negro, cerca del mirador, 27 iv 2010, de la Rosa & Barbar (BCRU 5211). Tierra del Fuego, Antártida e Islas del Atlántico Sur: Ushuaia, entre río Tuerto y lago Fagnano, sobre ruta 3, 10 iii 1995, Vobis & Messuti (BCRU 1331).

Lecanora torrida Vain

Arkiv. Bot. 8 (4): 45 (1909); type: Russia, Sibiria Septentrionalis: Peninsula Jinretlen, 67° lat. bor., 174° long. occid. (Greenw.), November 1878–July 1879, Almquist (S L1924!—holotype).

(Fig. 2A)

Fig. 2.

The Lecanora dispersa group in Argentina, habit. A, L. torrida [Messuti (BCRU 5202)]; B, L. wetmorei [Vobis (BCRU 522)]; C, L. zosterae var. zosterae [Vobis & Messuti (BCRU 1217)]. Scales: A–C = 1 mm.

Thallus ±developed, superficial, inconspicuous, discontinuous, consisting of flat, thin, whitish to pale brownish areoles.

Apothecia lecanorine, disciform, rounded, sessile, strongly constricted at the base, numerous, singly to frequently clustered in groups, usually deformed by mutual compression, 0·2–0·7 mm diam.; disc flat to convex, epruinose, greyish brown to black; margin well developed, conspicuous, entire, flexuose or crenate, white, epruinose to rarely pruinose, occasionally excluded. Amphithecium ±differentiated, 60–180 µm wide; algal layer dispersed in groups, continuous or discontinuous below the hypothecium; ±abundant or rare; cortex poorly differentiated, prosoplectenchymatous, thicker at base, 20–45 µm thick laterally, 50–75 µm thick basally, filled with granules (pol+), insoluble in K, soluble in N; parathecium distinct, hyaline, without crystals (pol−), 12·5–50 µm thick, prosoplectenchymatous, blackish on top; epihymenium brownish to olivaceous brown or blackish, gelatinous, K+ greenish brown, N+ reddish, 7·5–12·5 µm high, without crystals (pol−) to rarely with scarce, small granules (pol±), insoluble in K, soluble in N; hymenium hyaline, 45–60 µm high, with granules scattered throughout its height (pol+); subhymenium and hypothecium hyaline, composed of adglutinated hyphae, 25–75 µm high; paraphyses branched, with few anastomoses, ±free in K, 1·0–1·5 µm wide, tips expanded, with a dark cap, 2–3 µm wide. Asci clavate, 8-spored; ascospores hyaline, simple, ellipsoid to narrowly ellipsoid 8·9–14·6 × 4·9–6·5 µm.

Pycnidia not seen.

Chemistry. Thallus and apothecial margin K−, C−, PD± orange, UV−. Secondary metabolites detected by HPTLC: 2,7-dichlorolichexanthone, pannarin.

Ecology and distribution. This species occurs on rocks and is reported from Europe, North America, New Zealand and Antarctica (Poelt et al. Reference Poelt, Leuckert and Roux1995; Śliwa & Olech Reference Śliwa and Olech2002; Śliwa Reference Śliwa2007a; Valadbeigi & Sipman Reference Valadbeigi and Sipman2010). In Argentina it has been found on bones and on calcareous rocks. This is the first record for South America.

Remarks. Lecanora torrida differs from other taxa in the L. dispersa complex by having a non-granular epihymenium (pol−) and by the presence of granules (pol+) that are interspersed throughout the hymenium. It is anatomically and chemically similar to L. albescens and L. dispersa, but the latter two species have distinct epihymenial granules. Furthermore, they do not develop a conspicuous parathecium that is clearly visible and consists of bluish hyphae in the upper part, as in the case of L. torrida. The Argentinean specimens of L. torrida studied are also similar to L. zosterae var. beringii (Nyl.) Śliwa in the morphology of the thallus and the apothecia; however, in the latter species the parathecium is indistinct and the cortex is distinctly delimited. North American collections of L. torrida differ from material observed in this study by having a more developed thallus and entire apothecial margin.

Specimen examined. Argentina: Santa Cruz: a 2 km estancia Monte Aymond, camino al puesto de carabineros, en dirección a Punta Delgada (Chile), 52° 07′ 07″S, 69° 32′ 01″W, 226 m alt., 8 xi 1997, Messuti (BCRU 5202). Tierra del Fuego, Antártida e Islas del Atlántico Sur: Ushuaia, río Pipo, frente al campo Monseñor Alemán, sobre la ladera que mira al N, zona muy alberta, de renovales de lenga, Monte Susana, 11 iii 1995, Messuti, Ferraro & Vobis (BCRU 5222).

Lecanora wetmorei Śliwa

In Nash III, T. H., Ryan, B. D., Diederich, P. Gries, C. & Bungartz, F. (eds), Lichen Flora of the Greater Sonoran Desert Region 2: 293 (2004); type: USA, Utah, Salt Lake Co., E of Salt Lake City, along Big Cottonwood Canyon, on road to Brighton, on oak, at 5800 ft., 11 June 1967, Wetmore (MIN 722988!—holotype, KRAM-L 64137!—isotype).

(Fig. 2B)

Thallus not visible, immersed in the substratum, partly superficial, inconspicuous, crustose, thin, brownish to greyish.

Apothecia lecanorine, disciform, sessile to constricted at the base, occurring singly or clustered in groups, 0·4–1·1 mm diam.; disc flat to slightly convex, reddish brown to almost black, moderately to heavily pruinose; rarely epruinose, margin well developed, conspicuous, prominent or level with the disc, entire, flexuose in larger ascomata, smooth, white to greyish, covered by a dense white pruina. Amphithecium well developed, 75–200 µm wide; algal layer continuous to ±interrupted below the hypothecium; cortex distinct, hyaline to pale brownish, composed of agglutinated hyphae, with gelatinous walls, uniform in thickness to slightly thicker at base, 25–50 µm thick laterally, 60–90 µm thick basally, with granules (pol+), more abundant at the upper part of the margin, insoluble in K and soluble in N; parathecium indistinct, hyaline, prosoplectenchymatous, 12–25 µm thick; epihymenium brownish, reddish to yellowish brown, N+ reddish, 7·5–12·5 µm high, with thick granules (pol±), scarce, insoluble in K, insoluble in N, frequently with a conspicuous layer of additional thick granules (pol+), soluble in K, insoluble in N; epipsamma rarely present, insoluble in K, soluble in N; hymenium hyaline to brownish, 40–75 µm high; subhymenium and hypothecium hyaline, gelatinous, 50–75 µm high; paraphyses simple, rarely branched, not anastomosed, 1·5–2·0 µm wide, tips dilated with a dark brown cap, 3·0–3·5 µm wide. Asci clavate, 8-spored; ascospores hyaline, simple, ellipsoid to narrowly ellipsoid, 8·9–13·0 × 5·0–6·5 µm.

Pycnidia not seen.

Chemistry. Apothecia K−, C−, PD−, UV−. No secondary metabolites detected by HPTLC.

Ecology and distribution. Lecanora wetmorei grows on the bark of various trees. Hitherto, it has been recorded only from western North America (Ryan et al. Reference Ryan, Lumbsch, Messuti, Printzen, Śliwa, Nash, Nash, Ryan, Gries and Bungartz2004; Śliwa Reference Śliwa2007a) and Iran (Valadbeigi & Sipamn Reference Valadbeigi and Sipman2010). In Argentina it occurs on the bark of the following trees and shrubs: Austrocedrus chilensis (D. Don) Pic. Serm. & Bizzarri, Berberis buxifolia Lam., Nassauvia glomerulosa (Lag. Ex Lindl.) S. Don and Schinus patagonicus (Phil.) I. M. Johnst. in the Patagonian steppe and transitional forest. It also grows on exterior painted walls in urban areas of the San Carlos de Bariloche town. These are the first records of this species for South America.

Remarks. Lecanora wetmorei is characterized by its heavily pruinose apothecia, with entire margin, amphithecial cortex which is distinctly delimited, thicker at base, and epihymenium with two types of coarse granules (with different solubility). It can be mistaken for L. hagenii with similar pruinosity of ascomata, but the latter species differs by its paler discs, entire to slightly incised thalline margin and by the amphithecial cortex being inconspicuous and generally uniform in thickness (c. 25 µm). Some Argentinean specimens show a visible thallus, that is only slightly developed and inconspicuous. Moreover, a laterally thicker amphithecial cortex has been observed in the Argentinean material, by comparison with specimens from North America (Śliwa Reference Śliwa2007a).

Specimens examined. Argentina: Río Negro: San Carlos de Bariloche, barrio Jardín Botánico, calle Las Orquídeas 1243, 10 iii 2009, Vobis (BCRU 5205); ibid., 24 iii 2009, Vobis (BCRU 5228); ibid., 15 i 2010, Vobis (BCRU 5224); ibid., 6 i 2011 (BCRU 5225); Península San Pedro, esquina frente a capilla, 1 x 2008, de la Rosa (BCRU 5207); Pampa de Huenuleo, 25 ii 1992, Messuti (BCRU 5206); arroyo del Medio, 23 xi 1993, Messuti (BCRU 5203); Pilcaniyeu, cerca del río Pichileufu, 14 vi 1992, Messuti (BCRU 5208).

Lecanora zosterae (Ach.) Nyl. var. zosterae

Flora Meth. 59: 577 (1876).—Lecanora subfusca var. zosterae Ach., Syn. Meth. Lich. 1814: 158 (1814); type: Sweden, ‘… ad littora marina in foliis exsiccates Zosterae’ [sensu Brodo & Vitikainen (Reference Brodo and Vitikainen1984)] (H-ACH 1147 A—lectotype, image!).

For synonymy see Brodo & Vitikainen (Reference Brodo and Vitikainen1984).

(Fig. 2C)

Thallus growing within the substratum, or ±superficial, inconspicuous, very thin, evanescent, white to whitish or greyish, prothallus invisible.

Apothecia lecanorine, disciform, rounded, thin, sessile, strongly constricted at the base, peltate, numerous, crowded, 0·3–1·2 mm diam.; disc flat to concave, rarely convex, sinuose, epruinose, dark reddish brown to black; margin well developed, persistent, entire, thin, smooth, usually flexuose, with white pruina, involute when old, rarely excluded. Amphithecium distinct, ±60 µm wide; algae dispersed, filled with granules (pol−); cortex well defined, hyaline, gelatinous, compact, 40–60 µm thick laterally, 50–100 µm thick basally, with small crystals (pol+), insoluble in K, soluble in N; parathecium inconspicuous, 12–25 µm thick; epihymenium yellowish brown, pigment unaltered with K, N+ reddish to orange-brown, 5·0–12·5 µm high, not granular (pol−) epipsamma absent; hymenium hyaline, c. 40 µm high; subhymenium and hypothecium hyaline poorly developed, 20–50 µm high; paraphyses simple to sparsely branched, free, agglutinated, thin, c. 1·6 µm wide, slightly expanded to capitate, tips pigmented, c. 4 µm wide. Asci clavate, 8-spored; ascospores hyaline, simple, ellipsoidal to oval, 8·9–12·0 × 4·0–5·7 µm.

Pycnidia not seen.

Chemistry. Apothecial margin K−, C−, KC−, CK−, PD−. No secondary metabolites detected by HPTLC.

Ecology and distribution. Lecanora zosterae var. zosterae grows on organic substrata such as wood, debris and grass. This maritime lichen is widely distributed, and has been recorded from Europe, Asia and North America (Laundon Reference Laundon2003; Śliwa Reference Śliwa2007a). The specimens examined were found growing on the bark and wood of fallen branches in the vicinity of the coast in a sub-antarctic region of Argentina. This is the first record of the species in South America.

Remarks. This species is characterized by the large, often peltate apothecia with brownish discs, an amphithecial cortex which is distinctly delimited and clearly thickened at the base. Three morphological races, correlated with geographical distribution are recognized at varietal level (Śliwa Reference Śliwa2007a): Lecanora zosterae var. behringii and L. zosterae var. palanderi (Vain.) Śliwa are rather common in arctic-alpine regions, while L. zosterae var. zosterae has a widespread distribution. This typical variety is characterized by the large, up to 1·2 mm diam., peltate apothecia, with dark brown to reddish brown epruinose discs, which become sinuous and concave when old, with a thin, white to whitish grey, flexuous margin and an amphithecial cortex which is distinctly delimited, clearly thickened at the base. The related L. hagenii differs in having small sessile apothecia up to 0·9 mm diam., with plane, often pruinose discs (Laundon Reference Laundon2003). The Argentinean material presents the same morphological and anatomical characters as reported from North American and European specimens (Laundon Reference Laundon2003; Ryan et al. Reference Ryan, Lumbsch, Messuti, Printzen, Śliwa, Nash, Nash, Ryan, Gries and Bungartz2004; Śliwa Reference Śliwa2007a).

Specimen examined. Argentina: Tierra del Fuego, Antártida e Islas del Atlántico Sur: Ushuaia, Puerto Almanza, on the coast, 16 iii 1995, Vobis & Messuti (BCRU 1217); estancia San Luis, a 40 km de Río Grande, cerca de la costa del océano Atlántico, entre Punta María y estancia Viamonte, 14 iii 1995, Vobis (BCRU 5221).

Lecanora albescens (Hoffm.) Branth & Rostr

The species was recorded for the Chubut province on the basis of a single collection (Cengia Sambo Reference Cengia Sambo1930) by its synonym L. galactina (Ach.) Ach. This specimen could not be found in any known herbaria; no further collections of L. albescens have been identified.

Lecanora populicola (DC.) Duby

The only record of this species was published in the checklist of Argentinean lichens by Calvelo & Liberatore (Reference Calvelo and Liberatore2002). Unfortunately, reference material has not been found in any known herbaria.

Lecanora crenulata Hook

The collection cited for Argentina (Räsänen Reference Räsänen1941) has been identified in this study as L. flowersiana.