Introduction
Molecular investigation of lichenized-fungi has repeatedly shown that a single morphological ‘species’ is often comprised of several divergent genotypes, the so-called ‘cryptic species’ (e.g. Crespo & Pérez-Ortega Reference Crespo and Pérez-Ortega2009; Vondrák et al. Reference Vondrák, Říha, Arup and Søchting2009; Núñez-Zapata et al. Reference Núñez-Zapata, Divakar, Del-Prado, Cubas, Hawksworth and Crespo2011; Kraichak et al. Reference Kraichak, Lücking, Aptroot, Beck, Dornes, John, Lendemer, Nelsen, Neuwirth and Nutakki2015; Leavitt et al. Reference Leavitt, Esslinger, Divakar, Crespo and Lumbsch2016). Here we report the opposite situation, with the same genotype apparently responsible for ‘species’ the morphologies of which are so different that they were described in different genera.
The genus Endocena was described by Crombie (Reference Crombie1876 [1877]) from a collection made from Port Grappler on the west coast of Chile (49·4229°S, 74·2968°W) by R. O. Cunningham, who was the naturalist on board H.M.S. Nassau. Crombie included the single species E. informis Cromb. in his genus and, correctly, likened it to Siphula Fr., separating it from that genus by the thallus being hollow rather than solid (“Accedens ad Siphulas, facie fere conveniens, at thallo intus nonnihil cavo (vel parte axili medullae cava in toto thallo)”). The relationship of this monotypic genus to Siphula and its position within the Icmadophilaceae Triebel was confirmed by Stenroos et al. (Reference Stenroos, Myllys, Thell and Hyvönen2002).
Among the extensive lichen collections made by Henry Imshaug and co-workers from southern South America housed in the herbarium of Michigan State University (MSC: Fryday & Prather Reference Fryday and Prather2001), there are several collections from the Falkland Islands and Isla de los Estados that resemble E. informis but differ in being sorediate and having a thallus consisting of flat to convex areoles rather than the hollow pustules typical of E. informis. They are also chemically similar, both containing thamnolic acid. During recent fieldwork on the Falkland Islands by the first author, this entity was found to be frequent, growing among terricolous bryophytes on exposed peat or decaying stems of Blechnum magellanicum Mett., and was also discovered on Isla Grande de Tierra del Fuego by the third author.
The present study was initiated to confirm the placement of the new sorediate taxon in Endocena using molecular methods, but it revealed that both the new taxon and E. informis were congeneric with the recently described genus and species Chirleji buckii Lendemer & B. P. Hodk. Chirleji buckii is morphologically dissimilar to Endocena informis and resembles a species of the unrelated genus Leprocaulon Nyl. (Leprocaulaceae, Leprocaulales; Lücking et al. Reference Lücking, Hodkinson and Leavitt2016). It is known only from the type collection from Seno Agostini in the Parque Nacional Alberto de Agostini in the Chilean section of Isla Grande de Tierra del Fuego (Lendemer & Hodkinson Reference Lendemer and Hodkinson2012).
Materials and Methods
Morphology
The study is based chiefly upon collections made by Henry Imshaug and co-workers during fieldwork in southern South America between 1968 and 1971 and now held in the herbarium of Michigan State University (MSC; Fryday & Prather Reference Fryday and Prather2001) and recent fieldwork on the Falkland Islands and southern Chile by the first and third authors, respectively. Apothecial characteristics were examined by light microscopy on hand-cut sections mounted in water. Thallus sections were investigated, and anatomical measurements made, in 10% KOH. Standard chemicals were used for spot-test reactions and thin-layer chromatography followed the methods of Orange et al. (Reference Orange, James and White2001).
Molecular methods
Nuclear ITS rDNA was amplified using the primers ITS1f (Gardes & Bruns Reference Gardes and Bruns1993) and ITS4 (White et al. Reference White, Bruns, Lee and Taylor1990), and mitochondrial SSU rDNA using mrSSU1 (Zoller et al. Reference Zoller, Lutzoni and Scheidegger1999) and MSU7 (Zhou & Stanosz Reference Zhou and Stanosz2001). Protocols for DNA extraction, amplification and sequencing were the same as in Singh et al. (Reference Singh, Dal Grande, Divakar, Otte, Leavitt, Szczepanska, Crespo, Rico, Aptroot and Cáceres2015). The 18 new sequences were deposited in GenBank (Accession numbers KY495225–KY495242). Details of the specimens used in the phylogenetic analysis are given in Table 1.
Table 1 Specimen data and GenBank Accession numbers for the collections used in the phylogenetic analysis of Endocena shown in Fig. 1. Newly obtained sequences are in bold
Sequence selection and phylogenetic analyses
The new sequences were aligned with sequences of the Icmadophilaceae available in GenBank (Dibaeis spp., Icmadophila spp., Siphula spp. and Thamnolia vermicularis (Sw.) Schaer.), members of the Ochrolechiaceae (Ochrolechia spp.) and the species Chirleja buckii. Members of the Coccotremataceae (Coccotrema spp.) and Ochrolechiaceae (Ochrolechia spp.), which have been shown to be closely related to the Icmadophilaceae (Miadlikowska et al. Reference Miadlikowska, Kauff, Högnabba, Oliver, Molnár, Fraker, Gaya, Hafellner, Hofstetter and Gueidan2014; Lücking et al. Reference Lücking, Hodkinson and Leavitt2016) were used as outgroup. Gblocks v0.91b (Castresana Reference Castresana2000) was used to remove ambiguously aligned regions using the less stringent parameter settings allowing half gap positions. Model selection was performed using the Corrected Akaike Information Criterion (AICc) (Sugiura Reference Sugiura2007) as implemented in jModelTest v2.1.1 (Darriba et al. Reference Darriba, Taboada, Doallo and Posada2012). The best fitting models (SYM+I+G for ITS and GTR+G for mtSSU) were used in the subsequent analysis in MrBayes v3.2.1 (Huelsenbeck & Ronquist Reference Huelsenbeck and Ronquist2001). Two parallel MCMCMC runs were executed, each using four chains and 1000000 generations, and sampling trees every 100th generation. A 50% majority-rule consensus tree was generated from the combined tree sample after discarding the first 25% of the trees as burn-in.
Results
The ITS alignment was 515 bp long (274 variable sites (VS)) and 412 bp after Gblocks (203 VS). The mtSSU alignment was 840 bp long (215 VS) and 726 bp after Gblocks (199 VS). Members of the Icmadophilaceae form a supported monophyletic group in the phylogenetic tree (Fig. 1). Relationships within the family are not fully supported by either marker but some remarkable patterns are observable. The mtSSU tree shows a supported basal position for Thamnolia vermicularis within Icmadophilaceae; a similar position is shown in the ITS tree but is not statistically supported. The ITS tree further confirms that, as previously shown (Platt & Spatafora Reference Platt and Spatafora2000; Stenroos et al. Reference Stenroos, Myllys, Thell and Hyvönen2002; Grube & Kantvilas Reference Grube and Kantvilas2006; Ludwig Reference Ludwig2015), the genus Siphula is polyphyletic as currently understood. Ludwig (Reference Ludwig2015) further showed that the name Nylanderiella Hue is available for the S. decumbens group. Representatives of Endocena and Chirleja form a supported monophyletic group within the Icmadophilaceae in both trees. Comparison of all sequences of Endocena and Chirleja reveals two variable positions in the ITS alignment and none in the mtSSU alignment.
Fig. 1 Phylogenetic placement of the genus Endocena. Bayesian phylogeny based on ITS (A) and mtSSU (B) data. Thickened branches indicate posterior probabilities ≥95. All sequences of Endocena informis are newly generated for the present study, all others are from GenBank.
Examination of the type (and only) collection of Chirleja buckii revealed it to be morphologically distinct from both the other two taxa, consisting of short, erect pseudopodetia with granular-sorediate phyllocladia and resembling a species of Leprocaulon (Fig. 2A & B). Endocena informis differs significantly from Chirleja buckii in having a thallus composed of elongate, hollow pustules (Fig. 2C & D). The thallus of the sorediate taxon is similar to Endocena informis but differs in being crustose, lacking hollow pustules and developing soredia that are usually in discrete patches but occasionally cover the complete thallus giving it a leprose appearance (Fig. 2E & F). A comparison of the main characteristics of the three taxa is given in Table 2.
Fig. 2 A & B, Endocena buckii (Buck 57033—holotype), thallus with sporodochia. C & D, E. informis var. informis; C, ±crustose form (Fryday 11424); D, fruticose form (Imshaug 41064). E & F, E. informis var. falklandica; E, leprose form (Imshaug 52644); F, typical form with discrete soredia (Fryday 10741—holotype). Scales=1 mm. In colour online.
Table 2 Comparison of Endocena informis var. informis, E. informis var. falklandica, and E. buckii
Apothecia are reported for the first time from the genus (Fig. 3).
Fig 3 Apothecia of Endocena informis var. falklandica (Orange 19571). The lichenicolous fungus in the image appears to be different from the Sphaerellothecium sp. mentioned in the text, but it lacks fruiting bodies and its identity is uncertain. Scale=1 mm. In colour online.
Discussion
The ITS and mtSSU sequences of the three taxa are so similar that, based solely on the molecular data, all the collections might be included in a single species (E. informis). However, despite this genetic uniformity the morphological variation within the collections is remarkable (Fig. 2, Table 2). Two entities having almost identical ITS rDNA sequences but having such contrasting morphology that it was felt necessary to describe them in different genera, indicates that the use of ITS as the universal DNA barcode marker for fungi (Schoch et al. Reference Schoch, Seifert, Huhndorf, Robert, Spouge, Levesque and Chen2012) is not useful for all groups. It is known that ITS does not work well for highly speciose genera such as Fusarium (Al-Hatmi et al. Reference Al-Hatmi, Van Den Ende, Stielow, Van Diepeningen, Seifert, McCormick, Assabgui, Gräfenhan, De Hoog and Levesque2016) or Aspergillus (Samson et al. Reference Samson, Visagie, Houbraken, Hong, Hubka, Klaassen, Perrone, Seifert, Susca and Tanney2014) because it cannot discriminate among closely related species. Genera in the Icmadophilaceae are not highly speciose but they could have either evolved recently or display characteristic low levels of molecular evolution.
Recent evidence suggests that the capacity for lichens to consistently harbour secondary fungi might have been underestimated in the past (U’Ren et al. Reference U’Ren, Lutzoni, Miadlikowska, Laetsch and Arnold2012, Reference U’Ren, Riddle, Monacell, Carbone, Miadlikowska and Arnold2014; Spribille et al. Reference Spribille, Tuovinen, Resl, Vanderpool, Wolinski, Aime, Schneider, Stabentheiner, Toome-Heller and Thor2016) and one of the biggest current issues in lichen molecular taxonomy is that researchers fail to check which hyphae in their lichens are the source of their PCR products. This is especially relevant for sterile lichens such as Endocena where fruiting bodies are not available to be used as a source of DNA. Since we sequenced several collections of E. informis, we are confident that our PCR amplicons represent that species but, because C. buckii is known from only a single collection, there is a possibility that this is not the case for that species. However, we consider this unlikely because Lendemer & Hodkinson (Reference Lendemer and Hodkinson2012) provided two identical sequences from the single specimen and the chemistry of C. buckii is consistent with its position in the Icmadophilaceae.
We consider that the morphological differences exhibited by the three entities are sufficient to recognize them as distinct taxa; as two species with one comprising two varieties. Endocena informis itself is morphologically variable and specimens from the extremes of its range appear quite distinct. However, they are united by the basic thallus form of hollow pseudopodetia/pustules and, because intermediates occur and the two forms are sympatric in southern Chile, occurring together in the same population (cf. discussion under E. informis var. informis), they are retained here in a single taxon. It is clear from the molecular data that Chirleja should be included in the synonymy of Endocena but, because the thallus structure of C. buckii and E. informis are very different, they are retained here as distinct species and the new combination Endocena buckii (Lendemer & B. P. Hodk.) I. Schmitt, Fryday & Pérez-Ortega is proposed. The thallus structure of the sorediate taxon is closer to that of the subcrustose form of E. informis (with which it is sympatric) than E. buckii, and also marginally closer in the molecular analysis, and so the name E. informis var. falklandica Fryday, I. Schmitt & Pérez-Ortega is proposed for that taxon.
Taxonomic Section
Endocena Cromb.
J. Linn. Soc., Bot. 15: 226 (1876) [1877] emend. Fryday, I. Schmitt & Pérez-Ortega; type: E. informis Cromb. loc. cit.
Chirleja Lendemer & B. P. Hodk., N.Z. Jl Bot. 50(4): 451 (2012) syn. nov.; type: Chirleja buckii Lendemer & B. P. Hodk., loc. cit.
Thallus crustose to subfruticose, composed of hollow pustules or pseudopodetia, or solid pseudopodetia with granular phyllocladia on a thin primary thallus in one species; sorediate or not. Sporodochia present in one species.
Apothecia very rare and poorly developed, sessile, up to 2 mm diam., irregular, strongly concave, margin flexuose, irregular; disc strongly concave, pale pink-buff. No functional hymenium seen (Fig. 3).
Chemistry. Thamnolic acid by TLC.
Apothecia are reported here for the first time from the genus from four collections, two from E. informis var. falklandica and two from var. informis (see under ‘specimens seen’ for the respective taxa), but all are poorly developed (Fig. 3). They apparently first appear as thalline warts with a white, granular surface that expands and becomes pinkish as the white granules are dispersed on the expanding apothecium surface, which finally opens to reveal the apothecium disc.
Endocena buckii (Lendemer & B. P. Hodk.) I. Schmitt, Fryday & Pérez-Ortega comb. nov.
MycoBank No.: MB 819789
Chirleja buckii Lendemer & B. P. Hodk., N.Z. Jl Bot. 50(4): 451 (2012); type: Chile, Prov. Tierra del Fuego, Comuna Timaukel, Parque Nacional Alberto de Agostini, Isla Grande de Tierra del Fuego, S side of Seno Agostini, opposite Monte Buckland, 0–50 m elev., very wet Nothofagus forest with hepatic carpet on forest floor, on wood, 25.i.2011, W. R. Buck 57033 (NY (1726379)—holotype!; CONC—isotype).
Description adapted from Lendemer & Hodkinson (Reference Lendemer and Hodkinson2012).
Primary thallus thin, shiny, varnish-like, white, with scattered pale green ecorticate granules; secondary thallus of prostrate to suberect pseudopodetia with ecorticate granules resembling those found on the primary thallus; pseudopodetia solid, typically simple though sometimes with irregular branching; photobiont green, coccoid; cells globose, 7–10 µm diam.
Apothecia not observed.
Sporodochia borne on both the primary and secondary thallus, often at the apices of the pseudopodetia, hemispherical, cream-coloured and usually with a distinctly pinkish hue, 0·5–1·5 mm diam.; conidiophores not apparent; conidia hyaline, formed from hyphae derived from the primary thallus or pseudopodetia that thicken and become constricted at irregular intervals; transversely septate, 1(–2)-celled, 5–10×4–7 µm.
This species is known only from the type collection which was growing on the underside of a tree in a wet Nothofagus forest in southern Chile (Fig. 4C).
Fig. 4 Distribution of Endocena spp. A, projected distribution of E. informis var. informis from known collections; B & C, voucher collections of E. informis var. falklandica (●) and E. buckii (■).
Endocena informis var. informis Cromb.
J. Linn. Soc., Bot. 15: 226 (1876) [1877]; type: Chile, Port Grappler, 2.xii.1868, R. O. Cunningham (E (00429965)—holotype! (or, if not, lectotype, designated here. See discussion on typification below).
Siphula subtabularis Nyl. Lich. Fueg. Patag.: 3 (1888) syn. nov.; type: Argentina, Isla de los Estados, Port John, 1882, C. Spegazzini (H (9 503 897)—holotype).
Thallus±crustose-placodioid (Fig. 2C) to subfruticose, or truly fruticose (Fig. 2D) as originally described by Crombie (Reference Crombie1876 [1877]). Composed of crowded, branched lobes, up to 1·6 mm wide, but often all lobes irregularly isodiametric to shortly elongated, 0·7–2·8×0·7–1·0 mm; ivory white, matt, epruinose, convex, solid when young but soon developing a hollow interior, some lobe apices breaking open to reveal the hollow interior, inner surface rough or slightly granular and appearing sorediate.
Apothecia rare and poorly developed, observed on only two collections (Imshaug 40362, Pérez-Ortega 2631). See generic account above for description.
Conidiomata not observed.
Chemistry. K+ bright yellow, C−, Pd+ yellow, UV+ orange; thamnolic acid by TLC.
There are 117 collections of this taxon in MSC, with 32 from the Falkland Islands and 46 from Isla de los Estados. However, its range extends throughout southern Tierra del Fuego and northward along coastal Chile at least as far as Región de los Lagos (42°S). There is a distinct change in morphology along this latitudinal gradient, with collections from the west coast of Chile (including the type collection from Port Grappler, 49°26'S) having erect, subfruticose lobes (Figs. 2D, 5 & 6), whereas those from the southern part of the range (Tierra del Fuego, Isla de los Estados and the Falkland Islands) have decumbent lobes and appear almost crustose (Fig. 2C). The two forms are sympatric at Puerto Cutter (53°22·5'S, 72°25'W; Fig. 4A) on the Brunswick Peninsula and Seno del Almirantazgo (54·56989°S, 69·13509°W) in southern Chile where both can be observed in a single collection, even appearing to be part of the same thallus. A range of intermediates also occurs indicating that only one taxon is involved, which is confirmed by the molecular data. The nature of the substratum appears to be an important driver of thallus morphology and this, in turn, is possibly explained as a response to the differences in precipitation between the hyperoceanic climate of the west coast of Chile, where annual precipitation is in excess of 2000 mm (e.g. Puerto Aisen: 2238·5 mm y–1; Fig. 4A), and the drier south coast of Isla Grande de Tierra del Fuego, Isla de los Estados and the Falkland Islands, which experiences less than 600 mm y–1 (e.g. Ushuaia: 529 mm y–1; Fig. 4A). It is hypothesized that this wetter climate promotes bryophyte growth which provides support for the lobes of Endocena informis that consequently take on a fruticose habit.
Fig. 5 Herbarium sheet in E with holotype of Endocena informis. In colour online.
Fig. 6 Holotype of Endocena informis. In colour online.
The holotype specimen of Siphula subtabularis in H was annotated as Endocena informis Cromb. by Rolf Santesson in 1953, which is clearly correct. Because this specimen is in the herbarium where Nylander worked, it must be designated as the holotype. If a duplicate specimen is present in Spegazzini’s herbarium in Universidad Nacional de La Plata (LPS) it is unlikely that Nylander saw it and so it could not be considered as the holotype.
Selected specimens examined. Argentina: Tierra del Fuego: Isla de los Estados, Puerto Basil Hall, on plateau on S side of Puerto Abrigado, −54·76666°, −64·25000°, Astelia bog, 1971, Imshaug 51325 & Ohlsson (MSC0008898); ibid., Bahia Flinders, on ridge summit at head of W part of bay, −54·81667°, −64·60000°, exposed rock with small Nothofagus antarctica, 1971, Imshaug 53439 & Ohlsson, (MSC0008836); ibid., Bahia Capitan Canepa, on ridge on W side of N arm of bay, −54·83333°, −64·50000°, feldmark, 1971, Imshaug 52996 & Ohlsson, (MSC0008817); ibid., Puerto Vancouver, on E side of bay, −54·78333°, −64·05000°, cliffs, 1971, Imshaug 52060 & Ohlsson, (MSC0008808); ibid., Puerto San Juan, at head of bay, −54·75000°, −63·88334°, boggy slopes covered with Marsippospermum & occ. heath, 1971, Imshaug 51850 & Ohlsson, (MSC0008810); ibid., Puerto Celular, summit of mountain on S side of cove, −54·80000°, −64·31667°, 1971, Imshaug 52489 & Ohlsson, (MSC0004835); ibid., Puerto Cook, at SE corner of bay, −54·76667°, −64·01667°, alpine summit of mountain, 1971, Imshaug 51551 & Ohlsson, (MSC0004855); Isla Grande de Tierra del Fuego, Bahia Valentin, on E side of bay, −54·90000°, −65·43333°, open Marsippospermum bog with scattered Nothofagus, 1971, Imshaug 50378 & Ohlsson (MSC0008894,); ibid., Bahia Buen Suceso, on ridge behind bay, −54·80000°, −65·28333°, mosaic of dwarf Nothofagus groves and heath, 1971, Imshaug 50046 & Ohlsson (MSC0008892); ibid., Paso Garibaldi, −54·66667°, −67·91666°, dry border of schistous rock wall, 1969, Roivainen 882 (MSC0008828); ibid., to the E of Monte Olivia, Sierra de Sorondo, −54·71667°, −68·11667°, alpine region on summit of mountain, 1971, Imshaug 55586, 55602 & Ohlsson (MSC0004860, MSC0004861).—Chile: Región de los Lagos: Hualaihué, Fundación San Ignacio Huinay, 42°22'39''S, 72°22'57''W, 1128 m, peat bog and Nothofagus forest, 2014, Pérez-Ortega 3336, 3340 (MA); Región de Magallanes: Isla Grande de Tierra del Fuego, brazo suroeste del Seno Parry, 54°40'32''S, 69°26'25''W, 2–20 m, peat bog with granite boulders and Nothofagus betuloides, 2009, Pérez-Ortega 2628 (MAF), 2629, 2630 (epiphytic on Nothofagus pumilio), 2631 (with apothecia), 2632 (MA); ibid., Seno del Almirantazgo, Bahía Blanca, 54·56989°S, 69·13509°W, 0–15 m, peat bog and Nothofagus betuloides forest, 2009, Pérez-Ortega 2624 (MAF), 2625, 2626 (MA); Brunswick Peninsula, Puerto Cutter, along shore N of copper mine, 1967, Imshaug 39416, 39437, 39446 & Harris (MSC0008787, MSC0008799, MSC0008788); ibid., rock dome of Monte Condor, 1967, Imshaug 39480, 39482 & Harris (MSC0008789, MSC0008790); ibid., coastal rocks at copper mine, 1967, Imshaug 39496, 39539 & Harris (MSC0008791, MSC0008792).—Falkland Islands: East Falkland: Stanley, N peak of Two Sisters, UTM: 21F VC 3073 (−51°41·150', −58°1·150'), 800–900 ft (275 m), outcrops on summit ridge, 1968, Imshaug 40362 & Harris (MSC; with apothecia); Stanley Common, Two Sisters, −51·681705°, −58·003490°, 125 m, damp Empetrum heath, 2015, Fryday 10722 (MSC); ibid., −51·68574°, −58·01652°, 280 m, 2015, Fryday 10728 (MSC); ibid., −51·68574°, −58·01652°, 280 m, over bryophytes in crevice in rock face, 2015, Fryday 10730 (MSC); Mt Kent, east of road, before cliff, −51·67460°, −58·10640°, 425 m, over bryophytes among alpine boulder field, 2015, Fryday 10794, 10795, (MSC); Mt Usborne, between The Gap and summit, −51·691550°, −58·850976°, 400 m, over bryophytes on rock ledge, 2015, Fryday 11424. West Falkland: Port Howard, Mount Maria, lower end of Freezer Rocks, N-facing crags, −51·60989°, −59·55596°, 230 m, crevice in rock face, 2015, Fryday 10886, 10888 (MSC).
Endocena informis var. falklandica Fryday, I. Schmitt & Pérez-Ortega var. nov.
MycoBank No.: MB 819788
Similar to E. informis var. informis but with a crustose thallus that develops soredia.
Type: Falkland Islands, East Falkland, Stanley Common, Two Sisters, −51·68171°, −58·00349°, 125 m, peat in damp Empetrum heath, 18 January 2015, Fryday 10741 (MSC (0195387)—holotype!).
Thallus crustose, effuse white, composed of irregular, flat to convex areoles c. 0·3–0·7 mm diam., matt, epruinose. Soralia numerous, initially discrete but becoming confluent, greenish white when fresh, becoming cream-coloured with age; soredia 0·10–0·15 mm diam. Photobiont chlorococcoid; cells 10–15 µm diam.
Apothecia rare and poorly developed, observed on only two collections (Imshaug 52644, Orange 19571; see ‘Additional specimens seen’). See generic account for description.
Conidiomata not observed.
Chemistry. K+ yellow, C−, Pd+ yellow, UV+ orange; thamnolic acid by TLC.
Endocena informis var. falklandica is similar to E. informis var. informis but is readily separated from that taxon by having a crustose, areolate thallus rather than being composed of hollow pustules, and by the presence of soredia. In the field, it is easily distinguished by its dull creamy rather than shiny, ivory white thallus and also because it typically occupies a different ecological niche, being more strictly terricolous than var. informis. The new variety occurs predominantly among bryophytes on peat hags (the edge of an area from where the peat has been eroded away and that is consequently drier than surrounding areas) and moribund stems of Blechnum magellanicum rather than among other lichens and vascular plants over rocks, which is the most frequent habitat of var. informis. In fact, E. informis var. falklandica more closely resembles Ochrolechia frigida f. lapuensis (Vain.) Coppins or O. inequatula (Nyl.) Zahlbr., but the thallus of these taxa is C+ red due to the presence of gyrophoric acid.
Endocena informis var. falklandica is very frequent on the Falkland Islands (Fig. 4B) but apparently less so in Tierra del Fuego, being known from only two collections (Fig. 4C; see below).
Additional specimens examined . Argentina: Tierra del Fuego: Isla de los Estados, Puerto Celular, plateau on N side of cove, 54°47'S, 64°19'W, mosaic of Marsippospermum bog and heath, 1971, Imshaug 52644 & Ohlsson (MSC0008826; with apothecia).—Chile: Región de Magallanes: Isla Grande de Tierra del Fuego, Seno del Almirantazgo, Bahía Blanca, 54·56989°S, 69·13509°W, 0–15 m, peat bog and Nothofagus betuloides forest, 2009, Pérez-Ortega 2623, 2627 (MA).—Falkland Islands: East Falkland: Mt Usborne, The Gap, UTM 21F UC 7171, 900–950 ft, Cortaderia-heath, 1968, Imshaug 39903, 39907 & Harris (MSC0195393, MSC0195394); ibid., 51°43·44'S, 58°50·32'W, 170 m, on dead Bolax cushion in heathland, 2011, A. Orange 19559 (NMW); ibid., 51°43·32'S, 58°50·71'W, 200 m, on peaty soil amongst collapsing bush of Empetrum rubrum, 2011, A. Orange 19571 (NMW C.2011.015.170; with apothecia); ibid., −51·69155°, −58·85098°, 423 m, peat hag in grass heath, 2015, Fryday 11425 (MSC0195388); Port William, outcrops on N side of Gypsy Cove, 1969, Imshaug 41666 & Harris (MSC); Stanley Common, Two Sisters, −51·68171°, −58·00349°, 125 m, damp Empetrum heath, 2015, Fryday 10721 (MSC0195389). Weddell Island: Waterfall Valley, W of settlement, UTM 21F TC 2842, 750 ft, Empetrum heath, 1968, Imshaug 41857 & Harris (MSC0195395); ibid., 400 ft, Empetrum heath, 1968, Imshaug 41867 & Harris (MSC0195396; TLC); ibid., Empetrum heath between stream and stone run, 1968, Imshaug 41921 & Harris (MSC0195397); Circum Peak, NW side, −51·92760°, −60·92950°, 135 m, peat hag, 2015, Fryday 10854 (MSC0195390); between Waterfall Valley and Settlement, −51·90000°, −60·94300°, 145 m, peat in Empetrum heath, 2015, Fryday 10857 (MSC0195391). West Falkland: Hill Cove, NE base of French Peaks, UTM 21F TC 8188, 200 ft, stone run, 1968, Imshaug 41031 & Harris (MSC0195398; TLC); Fox Bay, NE from Sulivan House, UTM 21F TC 8952, 500 ft, outcrops on ridge, 1968, Imshaug 42337 & Harris (MSC0195399); Port Howard, between Freezer Rocks and Castle Rock, −51·60989°, −59·55596°, 230 m, Empetrum heath, 2015, Fryday 10891 (MSC0195392).
Distribution and ecology
The three taxa have different distributional ranges. Endocena informis var. informis is apparently widely distributed throughout southern South America from the Falkland Islands, through Isla de los Estados and Isla Grande de Tierra del Fuego and northward along the west coast of Chile, at least as far as Región de los Lagos (42°S). It has rarely been reported from Argentina. Calvelo & Liberatore (Reference Calvelo and Liberatore2002) cite only Grassi (Reference Grassi1950) for records of this species, who in turn cites only Zahlbruckner (Reference Zahlbruckner1917) who reported it from a single collection from the Hornby Mountains on West Falkland. The only other previous reports of which we are aware are those of the type collection of Siphula subtabularis from Isla de los Estados (see above) and Stenroos et al. (Reference Stenroos, Myllys, Thell and Hyvönen2002) who use a collection from Tierra del Fuego for their phylogenetic analysis. Despite this, collections in MSC indicate that it is frequent on Isla de los Estados (46 collections) and in southern Isla Grande de Tierra del Fuego (18 collections). Its apparent absence from further north in Argentina can probably be explained by the low precipitation resulting from the area being in the rain shadow of the Andes. Annual precipitation in Rio Gallegos, for example, is 242·2 mm compared to 529 mm at Ushuaia (Fig. 4A). The var. falklandica, by contrast, although frequent on the Falkland Islands (Fig. 4B) is much less frequent in Tierra del Fuego, being known from only two collections, one from Isla de los Estados and the other from Seno del Almirantazgo in Chile (Fig. 4C). Endocena buckii apparently has an even more restricted range, being known from a single collection from Seno Agostini on the Chilean part of Isla Grande de Tierra del Fuego (Fig. 4C).
There is also a report of E. informis from Macquarie Island, Australia (Kantvilas & Seppelt Reference Kantvilas and Seppelt1992?), which is based on a collection made by the Australian Museum Macquarie Island Expedition of 1977–78 (Lowry et al. Reference Lowry, Horning, Poore and Ricker1978) and further reported by Seppelt (Reference Seppelt1980). The lichens collected during this expedition were identified by D. J. Galloway (Filson Reference Filson1981) but we have been unable to locate the voucher collection of E. informis in any herbarium and the species is not represented on the Australian Virtual Herbarium (AVH 2017). We consider this report to be extremely dubious. It is the only report of the species from outside of southern South America and, although a distribution pattern of SW Chile–Campbell Plateau is not unusual (Fryday & Coppins Reference Fryday and Coppins2007), if the Macquarie Island report is correct it is strange that the species is not present among the over 4500 collections made by Imshaug and co-workers from Campbell Island and the Auckland Islands held in MSC (Fryday & Prather Reference Fryday and Prather2001). Filson (Reference Filson1981) mentioned the collection of E. informis by the Australian Museums Expedition but did not include the genus in his key to genera present on the island, which suggests that he also had doubts about its authenticity. We suspect that the specimen is actually a species of Coccotrema, Pertusaria or Siphula, most probably P. tyloplaca Nyl., which is frequent on Campbell Island and is also reported from Macquarie Island (Kantvilas & Seppelt Reference Kantvilas and Seppelt1992?).
The ecology of the three taxa included here in Endocena is also somewhat different. Although both varieties of Endocena informis are terricolous, primarily occurring in open heathland, the var. informis occurs mainly over or among bryophytes whereas the var. falklandica is more frequent on soil and peat hags. The single collection of E. buckii was made from the underside of a tree in a wet Nothofagus forest (Lendemer & Hodkinson Reference Lendemer and Hodkinson2012). However, one collection of E. informis var. informis (Pérez-Ortega 2630) was also made from this substratum and it is possible that E. buckii may be a primarily terricolous species but has been overlooked in that habitat.
Typification of Endocena
Crombie (Reference Crombie1876 [1877]) gives the collection details for Endocena informis as “Port Grappler, December 2nd 1868”. There are four co-types listed in the GBIF (2017) and Global Plants (2017 a ) databases: two in the Natural History Museum, London (BM) and one each in the Royal Botanic Garden Edinburgh (E) and the Botanische Staatssammlung München (M). There is also a collection in the Royal Botanic Gardens Kew (K) and two collections in the Nylander herbarium at the University of Helsinki (H-Nyl.).
The details of these collections are:
BM: Halt Bay, Chile, 21 April 1868 (BM001097291, BM001097292; Global Plants (2017 b )); E: Port Grappler, Dec. 2nd 1868 (E00429965; Global Plants (2017 c ), RBGE 2017); M: Port Grappler, W coast of Patagonia, 1869, Ex Herb. Kew (M0103214; Global Plants (2017 d )); K: Halt Bay, Chile, 21 April 1868 (K(M)233841); H-Nyl.: Mayne Harbour, W coast of Patagonia, April 1869 (H9211027); summit of hill, Mayne Harbour, 1869 (H 9211028).
Five of these collections, those in BM, E, M and one (H9211027) in H-Nyl, have been annotated “Endocena informis Cromb.” by Crombie and he also annotated the specimen in M and one of those in BM “gen. et sp. n”. The other collection in H-Nyl (H9211028) has no original annotation but was annotated “Endocena informis” by Santesson in 1953. The specimens in BM would originally have been housed in K and the label of the specimen currently in K, which was written by R. W. G. Dennis, was probably transcribed from the specimen in BM before it was transferred there in 1961. It is probable, but not certain, that this specimen was removed from the BM collection at the same time and retained in K as a separate voucher. Dennis annotated this specimen “E. informis var. digitata Cromb.” but this is an unpublished name.
The collections in BM, H-Nyl and K are clearly not type material because the date and locality are different from those cited by Crombie. In addition, either the date or the locality on the collection in M must be an error because HMS Nassau spent the early months of 1869 further south or on the east coast of Patagonia before leaving for England at the end of May (Cunningham Reference Cunningham1871). Because the collection in E is the only specimen explicitly associated with the date and locality given in the protologue it is considered here to be the holotype (Figs 5 & 6). Because the specimens in BM, M and one of those in H-Nyl (H9211027) were annotated by Crombie they are part of the “original material” (ICNafp Art 9.3; McNeill et al. Reference McNeill, Barrie, Buck, Demoulin, Greuter, Hawksworth, Herendeen, Knapp, Marhold and Prado2012) and are paratypes. The specimen in K is also probably a paratype but because there is no annotation from Crombie, and Dennis did not note whether it was removed from one of the collections currently in BM, this cannot be stated for certain. Alternatively, it could be argued that the specimens in E and M are both potentially type material because they were annotated as having been collected at Port Grappler and Cunningham collected there only on December 2nd 1868 and so the date on the specimen in M must be an error. In this case, the specimen in E should be selected as the lectotype because it better represents the habitat of the species. Because of this uncertainty, the suggestion made by McNeill (Reference McNeill2014) to provisionally designate a lectotype is taken above.
Lichenicolous fungi
Collections of Endocena informis var. informis sometimes show grey-coloured areas. In one case we identified a lichenicolous fungus (Sphaerellothecium sp.) as the cause of such coloration. Three species are known growing on species from the Icmadophilaceae: S. icmadophilae (R. Sant.) Zhurb. on Icmadophila ericetorum (L.) Zahlbr., S. siphulae Zhurb. on Siphula ceratites (Wahlenb.) Fr. and S. thamnoliae Zhurb. on Thamnolia vermicularis (Zhurbenko Reference Zhurbenko2015). Our specimen shows intermediate characters and does not fit with any of these species. It shows superficial vegetative hyphae, scattered immersed to sessile ascomata, 60–70 µm in diameter, and ascopores 11–14×5–6 µm. The high specificity exhibited by Sphaerellothecium growing on members of Icmadophilaceae and the deviant characters shown by our specimen point to the presence of an undescribed species on Endocena. Unfortunately, the scarcity of the material prevented us from describing a new taxon. Furthermore, two specimens of E. informis var. informis were colonized by the plurivorous species Spirographa fusisporella.
Spirographa fusisporella (Nyl.) Zahlbr.
Specimens seen. Chile: Región de los Lagos: Hualaihué, Fundación San Ignacio Huinay, 42°22'39''S, 72°22'57''W, 1128 m, peat bog and Nothofagus forest, 2014, Pérez-Ortega 3336 (sub Endocena informis var. informis, MA); Región de Magallanes: Isla Grande de Tierra del Fuego, brazo suroeste del Seno Parry, 54°40'32''S, 69°26'25''W, 2–20 m, peat bog with granite boulders and Nothofagus betuloides, 2009, Pérez-Ortega 2631 (sub Endocena informis var. informis, MA).
Sphaerellothecium Zopf sp.
Specimen seen. Chile: Región de los Lagos: Hualaihué, Fundación San Ignacio Huinay, 42°22'39''S, 72°22'57''W, 1128 m, peat bog and Nothofagus forest, 2014, Pérez-Ortega 3340 (sub Endocena informis var. informis, MA).
We thank Alan Orange (Cardiff) for his photograph in Figure 3 and the Royal Botanic Garden Edinburgh for permission to reproduce the images in Figures 5 & 6. The first author thanks the UK Government for funding (via the Darwin Initiative) to visit the Falkland Islands and collect lichens, and Falklands Conservation, in particular Dafydd Crabtree for logistical support while on the islands. We are grateful to Jürgen Otte (Frankfurt) and Fátima Durán for generating the DNA sequences. SPO thanks Leopoldo G. Sancho and E. Manrique (Madrid) for the opportunity to join the Tierra del Fuego (2009) and Huinay (2014) expeditions respectively. SPO is supported by grant RYC-2014-16784 from the Spanish Economy and Competitiveness Ministry. The curators of BM, CHR, HO and MEL are thanked for searching the collections under their care for the E. informis collection from Macquarie Island, and the curators of K and H-Nyl for providing information and images of the Cunningham collections of E. informis in their herbaria. John McNeill (Edinburgh) and Robert Lücking (Berlin) are thanked for useful discussion of typification issues. We also gratefully acknowledge the contributions of two anonymous reviewers whose constructive comments on a previous version of the manuscript greatly improved the current contribution.
