Lecanora confusoides Bungartz & Printzen, 2020

Bungartz, Frank, Elix, John A. & Printzen, Christian, 2020, Lecanoroid lichens in the Galapagos Islands: the genera Lecanora, Protoparmeliopsis, and Vainionora (Lecanoraceae, Lecanoromycetes), Phytotaxa 431 (1), pp. 1-85 : 62-65

Lecanora confusoides Bungartz & Printzen sp. nov. MycoBank no. 833376

Diagnosis. Similar to Lecanora confusa and L. perconfusa but with smaller ascospores [(6.5–)7.9–11.0(–13.0) × (3.5–)3.7–4.7(–5.0) µm], thalli that are blastidiate sorediate and contain an abundance of xanthones. Also resembles L. substrobilina , which is, however, not sorediate.

Type:— ECUADOR. GALÁPAGOS: Española, N of Punta Cevallos, inland from coast, 1˚23’4.3’’ S, 89˚37’44.7’’W, 13 m alt., dry zone, Cordia lutea shrubland with Prosopis juliflora and Vallesia glabra , on wood of Cordia lutea , 09-Nov-2010, Bungartz, F. 8833 ( CDS 45651– holotype).

( Fig. 16A–G )

Thallus corticolous or lignicolous, thin to moderately thickened, often at least in part endosubstratal, rimose-areolate; surface dull yellowish green to greenish beige, matt, epruinose, verruculose, sparsely to abundantly covered by irregular corticate granules [50–100 µm in diam.], bursting open to form poorly delimited, blastidiate soredia [25–35 µm in diam.]. Apothecia sparse to numerous, ±irregular to flexuose in outline, often densely crowded and ±deformed by mutual pressure, 0.5–1.3(–1.7) mm in diam., ±immersed to adnate, rarely sessile, biatorine to ±lecanorine, initially with a distinct proper margin that becomes excluded and successively replaced by a granular-blastidiate thalline margin, concolorous with the thallus, epruinose; disc plane to ± convex, often uneven, pale brown to beige, increasingly discolored with age, olivaceous to blackened, sparsely covered by a fine, whitish pruina; hymenium hyaline, not inspersed; epihymenium with small orange brown granules, soluble in K, lacking distinct crystals, fuscous brown (elachista -brown: dissolving in K, HCl± dull greenish, N−), occasionally in parts or entirely discolored by a diffuse aeruginose pigment (cinereorufa -green: intensifying in K, HCl+ bluish green, N+ reddish violet); proper exciple distinct, hyaline within, outer side concolorous with the epihymenium and covered with small orange brown granules soluble in K, granules at the base of the exciple often very abundant, often ±radiating along the hyphae from the lower inner to the lower outer part of the exciple; thalline exciple poorly to ±well developed, embracing the proper exciple from below, frequently disintegrating into blastidiate soredia; subhymenium and hypothecium hyaline; ascus clavate, Lecanora - type; ascospores 8/ascus, colorless, simple, rarely with one indistinct pseudoseptum, ellipsoid to narrowly ellipsoid or ±citriform (apically ±pointed), (6.5−)7.9−11.0(−13.0) × (3.5−)3.7−4.7(−5.0) µm (n = 30). Pycnidia immersed, ostiole brown, wall hyaline; conidia filiform 15−25 × ca. 0.8−1 µm (n = 15).

Chemistry: Thallus cortex including apothecial margin P−, C+ orange, KC+ orange, K± yellowish brown, UV− (dull, xanthones possibly restricted to the medulla); containing ±usnic acid [major], thiophanic acid [major], arthothelin [minor], 4-chloronorlichexanthone [minor], 5-chloronorlichexanthone [minor], ±zeorin [trace], 4, 5-dichloronorlichexanthone [trace]; [specimens analyzed with TLC: Aptroot, A. 64808 ( CDS 31383); Bungartz, F. 5404 ( CDS 29620), 7184 ( CDS 37668), 7206 A ( CDS 37690), 7207 ( CDS 37691), 7254 ( CDS 37738)].

Etymology: The specific epithet reflects the similarity of this species to Lecanora confusa .

Ecology and distribution: Known only from the Galapagos; occurs in the coastal to the transition zone, typically in ±exposed, sunny habitats, often on dry bark or decorticated wood of native trees and shrubs ( Bursera graveolens , Cordia lutea ) and cactus pads ( Opuntia megasperma var. orientalis ).

Notes: The new species belongs to a complex group of similar taxa that have been treated in detail by Printzen (2001). It is described here as new, for although the Galapagos specimens share many characteristics with L. substrobilina Printzen , L. confusa Alm. , and L. perconfusa Printzen , upon closer examination they differ from all of these species. Lecanora confusoides is most similar to L. substrobilina . The two species have similarly sized ascospores and a well developed proper exciple surrounded by a distinct, thalline exciple. However, the thalli of L. substrobilina remain esorediate, whereas the granules of L. confusoides typically burst open to form blastidiate soredia. Older apothecial discs of L. confusoides regularly become olivaceous due to an aeruginose pigment, and on treatment with K this aeruginose pigment intensifies, turning almost black. Such discoloration is rarely observed in L. substrobilina .

Printzen (2001) reported aggregations of soredia (“consoredia”) for L. perconfusa . The coarse soredia of L. confusoides are not formed by secondary aggregation. Instead they burst from minutely branched or ±granular thallus protuberances, breaking open to extrude soredia, a process perhaps best compared to the formation of blastidia. The thallus of L. perconfusa often lacks xanthones or contains them in lower concentrations than observed in L. confusoides . In addition, L. perconfusa has longer and more elongate ascospores than L. confusoides .

Older apothecia in L. confusa often develop an olivaceous to blackish tinge similar to that found in L. confusoides . This discoloration of the apothecial disc is not unusual in this species group and is most pronounced in L. sublivescens , a temperate species which lacks xanthones. Lecanora confusa is not known from the tropics and in western North America south of 28°N it is usually replaced by L. perconfusa Printzen (2001) . The ascospores of L. confusa are on average broader (4.0–5.7 µm wide) than those of L. confusoides . Thus L. confusoides is characterized by having some apothecia that are distinctly discolored, small ascospores, and epruinose thalli that invariably contain xanthones. Chemically L. confusa , L. confusoides , L. perconfusa and L. substrobilina are quite similar, but specimens of L. confusoides frequently lack usnic acid.

Superficially, specimens of Amandinea efflorescens var. pseudohypopelidna Marbach , a taxon also present in Galapagos, can appear quite similar to sterile material of L. confusoides . However, the thalli of the Amandinea are usually characterized by a conspicuous, compact black prothallus and its soredia are not formed from blastidiate protuberances. In the field the two species can easily be distinguished, the Lecanora has a characteristic greenish yellow color, A. efflorescens var. pseudohypopelidna is typically pinkish, a color cast lost when specimens are stored for prolonged periods in the herbarium.

Additional specimens examined (paratypes). ECUADOR. GALÁPAGOS: Española, N of Punta Cevallos, inland from coast, 1˚23’4.298’’ S, 89˚37’44.70’’W, 13 m alt., dry zone, Cordia lutea shrubland with Prosopis juliflora and Vallesia glabra , on Cordia lutea wood, 09-Nov-2010, Bungartz, F. 8833 ( CDS 45651); 1˚23’14.4’’ S, 89˚37’28.69’’W, 17 m alt., dry zone, Cordia lutea shrubland with lava boulders and pebbles, branch of Cordia lutea , on bark, 09- Nov-2010, Yánez-Ayabaca, A. 1565 ( CDS 45447); along S-coast of the island, near Punta Suárez, 1˚22’48.20’’ S, 89˚44’1.2’’W, 43 m alt., coastal zone, Cordia lutea shrubland with some Cryptocarpus pyriformis and lava boulders, on wood, 10-Nov-2010, Bungartz, F. 8874 ( CDS 45692). Gardner (near Española), central part of the island, walking up to the top, 1˚20’37.60’’ S, 89˚38’46.77’’W, 27 m alt., dry zone, lava flow of weathered AA-lava with open shrubby vegetation of Croton scouleri , Prosopis juliflora , few Bursera graveolens trees, and Opuntia megasperma var. orientalis , on S-exposed side of cactus pad, 12-Nov-2010, Bungartz, F. 9229 ( CDS 46047). Pinta, at the S-coast, a little E of Cabo Chalmers, 0˚33’2’’N, 90˚46’3’’W, 10 m alt., dry zone, old lava flow with scarce vegetation ( Opuntia galapageia , Alternanthera filifolia , Prosopis juliflora ), on trunk of Bursera graveolens , 01-Mar-2007, Bungartz, F. 6044 ( CDS 33723); along the trail up to the summit from the S-coast, 0˚33’22’’N, 90˚44’34’’W, 88 m alt., dry zone, open woodland of Bursera graveolens and few Opuntia galapageia with an understory of Croton scouleri , Castela galapageia , Waltheria ovata , Lantana peduncularis among pahoehoe lava, on twigs of Bursera graveolens , 28-Feb- 2007, Bungartz, F. 6013 ( CDS 33692); along the trail up to the summit, ca. 1 km inland from the S-coast, 0˚33’8’’N, 90˚44’29’’W, 54 m alt., dry zone, open vegetation of Bursera graveolens , Croton scouleri , Castela galapageia , and Opuntia galapageia among lava blocks, on upper side of branches of Bursera graveolens , 25-Feb-2007, Bungartz, F. 5658 ( CDS 33293). San Cristóbal, near Rosa Blanca, at the SE-coast of the island, 0˚49’27’’ S, 89˚21’6’’W, 2 m alt., coastal zone, lava plateau overlooking a lagoon, E- to SSE-facing with dwarf shrubs of Bursera graveolens and Croton scouleri on top, on branches of Bursera graveolens , 23-Apr-2007, Bungartz, F. 6370 ( CDS 34585), 6390 ( CDS 34605); 0˚49’31’’ S, 89˚21’4’’W, 1 m alt., coastal zone, lava plateau with small shrubs of Croton scouleri , few Opuntia megasperma and Rhizophora mangle towards the waterfront, on stilt root of dead Rhizophora mangle , 23-Apr-2007, Bungartz, F. 6340 ( CDS 34555); along trail from Bahía Sardinas at the NW-coast of the island to Cerro Pan de Azúcar, 0˚42’28’’ S, 89˚21’29’’W, 13 m alt., dry zone, open woodland of Bursera graveolens and Piscidia carthagenensis with dense understory of Scutia spicata , Gossypium darwinii and Waltheria ovata , on trunk of Bursera graveolens , 24-Apr- 2007, Bungartz, F.6481 ( CDS 34698), 6476 ( CDS 34693); trail to Cerro Mundo,passing by the“cañadas”, 0˚53’32.20’’ S, 89˚34’40.5’’W, 212 m alt., transition zone, with Bursera graveolens and shrubs of Clerodendrum molle , slope 15° W, branches of Bursera graveolens , on bark, 25-Aug-2008, Truong, C. 1471 ( CDS 39782). Santa Cruz, E-side of island, trail from parking lot to El Garrapatero beach, N-side of trail, 0˚41’26.69’’ S, 90˚13’19.10’’W, 6 m alt., dry zone, open deciduous forest of Bursera graveolens , Cordia lutea , Opuntia echios with Castela galapageia and Alternanthera echinocephala and others in the understory, Bursera graveolens , on bark, 16-Jun-2010, Nugra, F. 903 ( CDS 44950). Santa Fé, on top of lava flow at the N-coast of the island, 0˚48’12.4’’ S, 90˚2’34.5’’W, 13 m alt., coastal zone, open scrubland of partly dead shrubs ( Croton scouleri , Cordia lutea ), few shrubby Bursera graveolens , and Opuntia echios var. barringtonensis among lava rocks, on dead branch of Bursera graveolens , 25-Oct-2007, Bungartz, F. 7207 ( CDS 37691), 7184 ( CDS 37668), 7206 A ( CDS 37690); lava flow at the N-coast of the island, 0˚48’6.20’’ S, 90˚2’39.77’’W, 42 m alt., dry zone, S-exposed side of lava flow with scarce vegetation (shrubs of Croton scouleri , Cordia lutea , few Bursera graveolens trees, and Opuntia echios var. barringtonensis ), on branches of Bursera graveolens , 25-Oct-2007, Bungartz, F. 7254 ( CDS 37738). Santiago, at the W-coast of the island in Bahía Ladilla, 0˚18’8’’ S, 90˚49’56’’W, 10 m alt., coastal zone, S-exposed coastal lava cliff and boulders, on wood, 22-Jul-2006, Bungartz, F.5404 ( CDS 29620), summit of Cerro Gavilan, inner N- and NE-exposed crater rim, 0˚12’20’’ S, 90˚47’3’’W, 840 m alt., humid zone, N- and NE-exposed, steep basalt cliffs of crater rim with ferns ( Pityrogramma calomelanos var. calomelanos , Polypodium tridens , Dryopteris palmata , Adiantum concinnum , Blechnum polypodioides ) growing in crevices, on wood, 23-Mar- 2006, Aptroot, A. 65684 ( CDS 32275). Isabela, Volcán Alcedo, in the crater near fumaroles, 0˚27’1’’ S, 91˚7’19’’W, 780 m alt., transition zone, sulphur-influenced scrub on uneven lava, on wood, 07-Mar-2006, Aptroot, A. 64808 ( CDS 31383); along the trail going up the E-slope, basalt rubble field to the SE-side of the trail and the barranco, 0˚24’6’’ S, 91˚2’53’’W, 530 m alt., dry zone, basalt rubble field with scattered vegetation ( Bursera graveolens , Zanthoxylum fagara , Pisonia floribunda , Senna pistaciifolia ), Bursera , on bark, 10-Mar-2006, Aptroot, A. 64916 ( CDS 31495). Iabela, Volcán Darwin, southwestern foothills, above Tagus Cove, 0˚14’50’’ S, 91˚21’29.89’’W, 67 m alt., dry zone, open Bursera graveolens forest with Waltheria ovata and Macraea laricifolia , few Acacia rorudiana and Cordia lutea , along small lava flow, on N-exposed trunk of Bursera graveolens , 11-Nov-2007, Bungartz, F. 7343 ( CDS 37830).

Specimens examined for comparison; Lecanora substrobilina . USA. ARIZONA. Mendocino County, adjacent to Mendocino County airport, pine-cypruss pigmy forest, on Pinus radiata cones, 39.2613889˚N, 123.7505556˚W, 175 m alt., 14-Aug-1975, Nash III , T. H. 11417 & Ryan, B. D. ( ASU) ( TLC Elix: usnic acid [major], thiophanic acid [major], arthothelin [minor], 4-chloronorlichexanthone [minor], 5-chloronorlichexanthone [minor], zeorin [trace], 4,5- dichloronorlichexanthone [trace]) .

Lecanora confusa . MEXICO. BAJA CALIFORNIA. Along the road to Agua Caliente (just east of Ensenada ), 1.6 km from Mex. Ret. 3 between Ensenada and San Felipe, 31˚53’N, 116˚22’W, on large shrub of Fraxinus trifoliata , 10- Feb-1994, Rebman , J. P. 2172 & Resendiz, M. E. ( ASU) ( TLC Elix: usnic acid [major], thiophanic acid [major], zeorin [minor], arthothelin [trace]) .

Figures

FIGURE 16. Species in the L. varia-group. A–G. Lecanora confusoides. A–B. Thallus variation on different substrates. A. Thick, rimoseareolate thallus with ±adnate apothecia, disc brown, in parts with a dark grayish tinge, distinctly pruinose, on fibrous bark of Cordia (Bungartz, F. 8833, CDS 45651–holotype). B. Thin, endosubstratal to rimose, abundantly blastidiate-sorediate thallus with ±immersed apothecia, the apothecial margin blastidiate-sorediate (Bungartz, F. 7207, CDS 37691). C. Filiform conidia (Bungartz, F. 8833, CDS 45651). D. Asci with narrowly oblong ascospores (Bungartz, F. 8833, CDS 45651). E–G. Apothecial sections (in water, DIC). E. Proper exciple well developed, abundantly inspersed with small, orange granules, thalline exciple below reduced (Bungartz, F. 6044, CDS 33723). F. Proper exciple well developed, sparsely interspersed with small, orange granules, thalline exciple below moderately developed (Bungartz, F. 8833, CDS 45651). G. Proper exciple well developed, sparsely interspersed with small, orange granules, thalline exciple along the outside well developed, but ±disintegrating (Bungartz, F. 8833, CDS 45651). Scales: A & B = 5 mm; C = 20 µm; D = 10 µm; E, F & G = 100 µm.