Lecanora sulfurescens Fée (1837: 313) MycoBank

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 : 57

Lecanora sulfurescens Fée (1837: 313) MycoBank no. 389407

Type:— BRASIL. RIO DE JANEIRO: exact locality unknown, 1869, Glaziou, A.F.M. 3850 [ UPS – lectotype selected by Lumbsch & Elix

(1993), PC– isolectotype].

( Figs. 10E–F , 11A–C )

Thallus saxicolous, thin to moderately thickened, distinctly areolate, areoles initially scattered on a whitish fibrous to arachnoid prothallus, with age becoming contiguous, their edges closely adjoining; surface white to pale gray or pale greenish gray, roughened to verruculose, dull, epruinose to whitish pruinose, lacking soredia; prothallus well developed, whitish arachnoid, but reduced with age and ultimately appearing as a whitish line delimiting the thallus, rarely blackened. Apothecia numerous, often very densely aggregated, circular to slightly irregular in outline, 0.4–1.1 mm in diam., immersed to adnate, rarely sessile, typically very crowded, cryptolecanorine to distinctly lecanorine with a roughened to barely verrucose, epruinose to whitish pruinose margin, concolorous with the thallus; disc plane to slightly convex, yellowish orange to brownish orange, epruinose or weakly pruinose; hymenium hyaline, not inspersed, epihymenium with crystals, almost hyaline to pallid yellowish brown (elachista -brown: dissolving in K, HCl± dull greenish, N−), both pigment and crystals soluble in K (chlarotera - type); proper exciple thin, indistinct, with few crystals insoluble in K; thalline exciple thick, ±corticate, with large crystals insoluble in K (pulicaris - type); hypothecium hyaline; ascospores 8/ascus, simple, ellipsoid to broadly ellipsoid, (6.9)–8.2–10.3–(11.9) × (4.5–)4.6– 5.3(–5.9) µm (n = 30). Pycnidia not seen.

Chemistry: Thallus cortex including apothecial margin P+ yellow, C−, KC−, K+ yellow; with atranorin [major], ±leoidin [major], ±gangaleoidin [minor or major], ±chlorolecideoidin [minor]; [specimens analyzed with TLC: Bungartz, F. 4564 ( CDS 28650), 3404 ( CDS 27110)].

Ecology and distribution: Pantropical (North and South America, Africa, Australasia), previously reported from Galapagos ( Weber 1986, Elix & McCarthy 1989, Guderley 1999); among the most common and most abundant saxicolous species, occurring throughout all vegetation zones, in a large variety of sheltered and exposed habitats, inside crevices and cracks, shaded overhangs, exposed cliffs, on the top of boulders, in dust rich habitats near the ground, and frequently also on tortoise carapaces.

Notes: As previously reported by Lumbsch & Elix (1993) L. sulfurescens is characterized by the gangaleoidin chemosyndrome. However, Guderley (1999) also included gangaleoidin deficient forms, and unlike Lumbsch & Elix (1993), treats L. depressa Fée as a synonym of L. sulfurescens . We follow this view: some Galapagos specimens here identified as L. sulfurescens contained only atranorin.

Specimens from continental South America generally appear to have epruinose apothecial discs ( Guderley 1999), while some specimens from the Galapagos have pruinose apothecia.

Specimens examined. ECUADOR. GALÁPAGOS: Darwin, Dawson, E.Y. s.n. (L-40895, COLO 190276). Española, along S-coast of the island, near Punta Suárez, 1˚22’52.39’’ S, 89˚43’52.60’’W, 52 m alt., coastal zone, SE-exposed coastal cliff, on rock, 10-Nov-2010, Bungartz, F. 8875 ( CDS 45693); along S-coast of the island, SE of Punta Suárez, ca. 500 m inland from coast, 1˚22’56.60’’ S, 89˚43’8.40’’W, 133 m alt., dry zone, lava cliff with Cordia lutea , Ipomoea habeliana and few trees of Bursera graveolens , slope of lava outcrop, on rock, 10-Nov-2010, Yánez-Ayabaca, A. 1631 ( CDS 45518); Punta Cevallos at E-coast of island, 1˚23’38.10’’ S, 89˚37’8.5’’W, 26 m alt., coastal zone, basalt cliff almost bare of vegetation, some Ipomoea habeliana , on rock, 09-Nov-2010, Bungartz, F. 8808 ( CDS 45626); 1˚23’3.70’’ S, 89˚37’44.77’’W, 20 m alt., dry zone, SE-exposed basalt cliff with some Cordia lutea shrubs, slope of rock; sunny, on rock, 09-Nov-2010, Yánez-Ayabaca, A. 1572 B ( CDS 54892). Floreana, lava flow near the shore just N of Black Beach, dry zone, 24-Apr-1976, Weber, W.A. s.n. (L-62978, COLO 294544); Cerro Pajas, inside the crater, around the small hut, at the end of trail off the dirt road to the highlands, 1˚17’50.5’’ S, 90˚27’23.19’’W, 376 m alt., humid zone, open, SE-exposed slope of lava cliff and boulders with some ferns, on rock, 12-Jan-2011, Bungartz, F. 9367 ( CDS 46654), 9420 ( CDS 46707); trail going to Post Office Bay off the dirt road between highlands and Puerto Velasco Ibarra, cliff at NE-side of trail (Mirador), 1˚17’4.298’’ S, 90˚26’36.60’’W, 365 m alt., transition zone, ca. 10 m high lava cliff within dense scrub of Clerodendrum molle , Croton scouleri and Macraea laricifolia , one single Acacia rorudiana on top of cliff, on rock, 25-Jan-2011, Bungartz, F. 10229 ( CDS 47648); lower S-slope of Cerro Ventanas, 1˚16’36.10’’ S, 90˚25’41.10’’W, 295 m alt., transition zone, open shrubland of Macraea laricifolia and some lower Waltheria ovata shrubs in between, on rock, 18-Jan-2011, Bungartz, F. 9859 ( CDS 47197). Campéon (near Floreana), S-side, bare lava talus, 23-Apr-1976, Weber, W.A. s.n. (L-62783, COLO 294737). Gardner (near Floreana), NW-side of the island, 1˚19’50.5’’ S, 90˚17’48.70’’W, 69 m alt., coastal zone, upper coastal zone, Grabowskia boerhaaviaefolia scrub with Scalesia villosa and Opuntia megasperma , on rock, 23-Jan-2011, Bungartz, F. 10111 ( CDS 47506). Pinta, along the trail up to the summit from the S-coast, 0˚34’3’’N, 90˚44’56’’W, 233 m alt., transition zone, open woodland with Bursera graveolens , Zanthoxylum fagara , Pisonia floribunda , Croton scouleri , and few Opuntia galapageia among old lava flows; in between Alternanthera filifolia and grasses, on rock, 28-Feb-2007, Bungartz, F. 5968 ( CDS 33646). Pinzón, in the valley on the W-slope of the highest mountain, 0˚36’41’’ S, 90˚40’11’’W, 310 m alt., dry zone, dry zone vegetation with Prosopis juliflora , Alternanthera filifolia , Maytenus octogona , and Croton scouleri , basalt, on rock, 16-Feb-2006, Aptroot, A. 64094 ( CDS 30655); E-facing side of a valley on the W-slope of the highest mountain, 0˚36’49’’ S, 90˚40’14’’W, 294 m alt., transition zone, dry transition zone with E-facing basalt cliff and Scalesia baurii ssp. baurii ; Polypodium tridens growing on the basalt cliff, vertical front of basalt cliff, on rock, 16-Feb-2006, Bungartz, F. 3595 ( CDS 27413). San Cristóbal, Pan de Azúcar, inland from Bahía Sardinas at the NW-coast of the island, 0˚43’6’’ S, 89˚21’19’’W, 88 m alt., dry zone, NE-facing slope near the top of the first small hill with low shrubs of Alternanthera filifolia and few Bursera graveolens trees, on rock, 24-Apr-2007, Bungartz, F. 6416 ( CDS 34631); 0˚43’13’’ S, 89˚21’14’’W, 155 m alt., dry zone, E- to SE-exposed cliff at E-facing slope of the hill, on rock, 24-Apr- 2007, Bungartz, F. 6433 ( CDS 34648); inland from Punta Pit at the NE-coast of the island, 0˚43’6’’ S, 89˚14’36’’W, 20 m alt., dry zone, NNW-exposed slope of old lava flow with scarce vegetation, on rock, 20-Apr-2007, Bungartz, F. 6087 ( CDS 33766), 6098 ( CDS 33777); S of Punta Pit at the NE-coast of the island, 0˚42’50’’ S, 89˚14’48’’W, 6 m alt., dry zone, NE-exposed slope of hill with abundant Mentzelia aspera , few shrubs of Cordia lutea and basalt boulders in between, on rock, 21-Apr-2007, Bungartz, F. 6128 ( CDS 33807); slope of Cerro Tortuga, ca. 4 km inland from the NW-coast, 0˚44’51’’ S, 89˚23’25’’W, 155 m alt., dry zone, rocky S-exposed slope with few Bursera graveolens , Piscidia carthagenensis , Zanthoxylum fagara , and Mentzelia aspera in the understory, on rock, 25-Apr-2007, Bungartz, F. 6562 ( CDS 34780); Cerro Mundo, at the top of the rock cliffs on the S side close to the summit, 0˚53’19.5’’ S, 89˚34’24.30’’W, 282 m alt., transition zone, with Bursera graveolens , Croton scouleri and Jasminocereus thouarsii , slope 15° S, protected rock cracks on the cliff, on rock, 25-Aug-2008, Clerc, P. 08-395 ( CDS 40249). Santa Cruz, on rock, Hill, T. s.n. ( FH-TUCK 197160); Puerto Ayora, near begin of road to Baltra, 0˚44’34’’ S, 90˚18’45’’W, 25 m alt., dry zone, lava, on rock, 26-May-2005, Aptroot, A. 63093 ( CDS 29823); cliff N of the town, 0˚43’59’’ S, 90˚18’45’’W, 20 m alt., dry zone, lava, on rock, 11-Feb-2006, Aptroot, A. 63709 ( CDS 30264); along shore E of Puerto Ayora near Charles Darwin Research Station ( CDRS), 0˚44’38’’ S, 90˚18’1’’W, 1 m alt., coastal zone, coastal lava, on rock, 29- May-2005, Aptroot, A. 63265 ( CDS 30000); 0˚44’35’’ S, 90˚18’14’’W, 1 m alt., coastal zone, bare lava rocks, Cryptocarpus pyriformis occasionally in between, on rock, 10-Feb-2006, Bungartz, F. 3404 ( CDS 27110), 3416 D ( CDS 54836); Bungartz, F. 3421 ( CDS 27127); 0˚44’45’’ S, 90˚17’39’’W, 20 m alt., coastal zone, coastal lava, on rock, 29-May-2005, Aptroot, A. 63291 ( CDS 30031), 63292 ( CDS 30032); 0˚44’53’’ S, 90˚18’14’’W, 1 m alt., coastal zone, bare lava rocks, Cryptocarpus pyriformis occasionally in between, on rock, 10-Feb-2006, on the North side of the island, along the dirt road to the ash quarry Mina Granillo Rojo , 0˚36’56’’ S, 90˚22’3’’W, 570 m alt., transition zone, lower transition zone; dry semi-deciduous forest with Bursera graveolens and Zanthoxylum fagara , lava, on rock, 23- Feb-2006, Aptroot, A. 64542 ( CDS 31114); vicinity of Academy Bay, 0.8 km E of Darwin Station, coastal zone, shore boulders just above high tide mark, on rock, 15-Feb-1964, Weber, W.A. s.n. (L-40056, COLO 188286), s.n. (L-40059, COLO 188279), s.n. (L-40996, COLO 190372); vicinity of Academy Bay, first barranca behind seismic station, dry zone, talus of barranca, 15-Feb-1964, Weber, W.A. s.n. (L-40861, COLO 190340); at top of barranco near seismic station, 30 m alt., dry zone, on rock, 13-Apr-1976, Weber, W.A. s.n. ( CDS 10832), s.n. ( QCA); cliff at the end of the trail inland from the Charles Darwin Research Station ( CDRS), Puerto Ayora, 0˚44’16.39’’ S, 90˚18’6.298’’W, 35 m alt., dry zone, deciduous forest of Bursera graveolens , Opuntia echios , and Jasminocereus thouarsii , exposed basalt rock, on rock, 17-Oct-2007, Ertz, D. 11518 ( CDS 36842); above the quarry Mina Granillo Rojo , off the main road to the channel, on the N-side of the island, 0˚37’5.798’’ S, 90˚21’59.10’’W, 617 m alt., transition zone, open and dry forest of mainly Psidium galapageium , with some Scalesia pedunculata and Pisonia floribunda , and basalt outcrops, on rock, 21-Oct-2007, Bungartz, F. 7126 ( CDS 37611); 0˚37’7.5’’ S, 90˚21’55.5’’W, 607 m alt., transition zone, upper transition zone with Bursera graveolens , Psidium galapageium , Scalesia pedunculata and Opuntia echios , outcrop of basaltic rocks, W-exposed, basaltic rock, on rock, 07-Aug-2008, Clerc, P. 08-40 ( CDS 39894); E-side of island, along road from Cascajo to El Garrapatero, 0˚40’22.10’’ S, 90˚14’41.70’’W, 137 m alt., transition zone, lower transition zone, open mixed forest of Bursera graveolens , Pisonia floribunda , Piscidia carthagenensis , Psidium galapageium , Erythrina velutina with an understory of Plumbago scandens , Alternanthera halmifolia , Bastardia viscosa , Zanthoxylum fagara a, on rock, 16-Jun-2010, Nugra, F. 890 ( CDS 44970). Plaza Norte (near Santa Cruz), 0˚34’47’’ S, 90˚9’47’’W, 1 m alt., coastal zone, vertical, S-exposed cliffs and on top of island inpenetrable thicket of Grabowskia boerhaaviaefolia and Scutia spicata var. pauciflora with occasional Opuntia in between, S-exposed front to overhanging basalt cliff; sunny, somewhat sheltered, on rock, 21-Feb-2006, Aptroot, A. 64399 ( CDS 30965); Bungartz, F. 3815 ( CDS 27697); coastal zone, 15-Feb-1964, Weber, W.A. s.n. (L-41047, COLO 193085). Plaza Sur (near Santa Cruz), coastal zone, 13-Feb-1964, Weber, W.A. s.n. (L-40112, COLO 188087); 0˚34’59’’ S, 90˚9’54’’W, 1 m alt., coastal zone, eastern part with scattered, low vegetation of Sesuvium portulacastrum & Tiquilia galapagoa with occasional Opuntia , western part also with scattered scrubs of Grabowskia boerhaaviaefolia , Maytenus octogona , and Castela galapageia , on rock, 21-Feb-2006, Aptroot, A. 64451 ( CDS 31019); Bungartz, F. 3760 ( CDS 27642), 3761 ( CDS 27643). 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 rock, 25-Oct-2007, Bungartz, F. 7228 ( CDS 37712). Santiago, along the trail from Bucanero to Jaboncillos, ca. 3 km SE of Bucanero, 0˚10’52’’ S, 90˚48’33’’W, 362 m alt., transition zone, open woodland of large Bursera graveolens and smaller Psidium galapageium trees, grassland and basalt boulders in between, on rock, 22- Mar-2006, Bungartz, F. 4617 ( CDS 28704), 4643 ( CDS 28730); Aptroot, A. 65400 ( CDS 31986); ca. 1 km below the summit, Cerro Gavilan, 0˚11’45’’ S, 90˚47’20’’W, 680 m alt., transition zone, open Psidium galapageium forest with Zanthoxylum fagara , Blainvillea dichotoma , Mentzelia aspera and Senna obtusifolia , basalt boulders and outcrops in between, on rock, 22-Mar-2006, Bungartz, F. 4666 ( CDS 28753); ca. 500 m S of Bucanero, near the canyon at the northeastern foothills of Cerro Cowan, 0˚10’21’’ S, 90˚49’30’’W, 70 m alt., dry zone, open woodland with Castela galapageia , Cordia lutea , Vallesia glabra , Opuntia galapageia , lava, on rock, 21-Mar-2006, Aptroot, A. 65345 ( CDS 31931); 0˚10’23’’ S, 90˚49’30’’W, 68 m alt., dry zone, upper SE-exposed steep cliff of conglomerated ash of the canyon with shrubs of Castela galapageia and few Bursera graveolens trees, on rock, 21-Mar-2006, Bungartz, F. 4564 ( CDS 28650); Cerro Gavilan, boulder field on the outer, S-exposed slope, 0˚12’25’’ S, 90˚47’4’’W, 830 m alt., humid zone, basalt boulder field with scattered vegetation ( Portulaca oleraceum , Ageratum conyzoides , Cyperus virens , Digitaria ciliaris ), on rock, 24-Mar-2006, Bungartz, F. 4822 ( CDS 28988); small hill ca. 1 km inland from the E-coast, at the same latitude as Bartolomé, 0˚17’40’’ S, 90˚35’10’’W, 77 m alt., dry zone, SW-exposed slope of small hill with occasional Bursera graveolens trees and few shrubs ( Castela galapageia and Scutia spicata var. pauciflora ), Wexposed slope of old lava flow, S-exposed front of small basalt rock, on rock, 20-Jul-2006, Bungartz, F. 5276 ( CDS 29492); on NW-side of cinder cone 1 km SE of Santiago Bay, 0˚15’0’’ S, 90˚51’15’’W, 30 m alt., dry zone, along sides of trench containing the spring, on consolidated ash, 24-Apr-1971, Pike, L.H. s.n. (L-55193, COLO 255621); 1 km SE of James Bay, 0˚15’0’’ S, 90˚51’15’’W, 30 m alt., dry zone, along sides of trench containing the spring on NW side of cinder cone, on consolidated ash, 24-Apr-1971, Pike, L.H. 2620 (0, OSC 99350). Wolf, Cavagnaro, D. s.n. (L-40916, COLO 190113). Isabela, Volcán Alcedo, outer SE-exposed slope and crater rim, 0˚27’29’’ S, 91˚7’19’’W, 1089 m alt., humid zone, tortoise pasture with scattered trees ( Tournefortia rufo-sericea , Zanthoxylum fagara ), lava, on rock, 05- Mar-2006, Aptroot, A. 65113 ( CDS 31695); Bungartz, F. 4054 ( CDS 27984); on inner crater rim above the fumaroles, 0˚27’29’’ S, 91˚7’19’’W, 1089 m alt., humid zone, disturbed by former grazing of goats therefore scattered trees ( Tournefortia rufo-sericea , Zanthoxylum fagara ), on rock, 05-Mar-2006, Bungartz, F. 4062 ( CDS 27992); upper NNWexposed slope inside the crater, 0˚27’27’’ S, 91˚7’23’’W, 1055 m alt., humid zone, open vegetation with Adianthus concinnum , and scattered shrubs of Tournefortia rufo-sericea among basalt rocks, on rock, 05-Mar-2006, Bungartz, F. 4090 ( CDS 28054); Aptroot, A. 64894 A ( CDS 31471); along the trail going up the E-slope, at the NW-side of the trail, 0˚24’2’’ S, 91˚2’36’’W, 410 m alt., dry zone, basalt boulders and outcrops at the NW-exposed slope of the barranco, Bursera graveolens and Zanthoxylum fagara growing in between, on rock, 09-Mar-2006, Bungartz, F. 4386 ( CDS 28471); 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 ), Pisonia , on bark, 10-Mar-2006, Aptroot, A. 64933 ( CDS 31512); on the crater rim near the hut, 0˚26’33’’ S,91˚5’31’’W, 1100m alt.,humid zone, Pteridium arachnoideum and Stachytarpheta cayennensis , scattered low shrubs of Tournefortia rufo-sericea and outcrops of basalt tuff in between, basalt, on rock, 07-Mar-2006, Aptroot, A. 65283 ( CDS 31869); ca. 100 m inland from the shore a little N of Cowley, 0˚24’4’’ S, 91˚0’1’’W, 45 m alt., coastal zone, plane with small pebbles of lava tuff, mostly open, occasional groups of small Bursera graveolens trees, shrubs of Scalesia affinis , Cordia lutea , Scutia spicata var. pauciflora , lava, on rock, 11- Mar-2006, Aptroot, A. 64740 ( CDS 31315); outer SE-exposed slope, ca. 100 m below the crater rim, 0˚25’36’’ S, 91˚5’12’’W, 1146 m alt., humid zone, disturbed by former grazing of goats, Pteridium arachnoideum and Stachytarpheta cayennensis , scattered low shrubs of Tournefortia rufo-sericea and outcrops of basalt tuff in between, on rock, 06-Mar- 2006, Bungartz, F. 4177 ( CDS 28208). Volcán Darwin, southwestern slope, 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, 11-Nov-2007, Bungartz, F. 7329 ( CDS 37816); 0˚13’59’’ S, 91˚20’8’’W, 597 m alt., dry zone, open Bursera graveolens forest with Croton scouleri and Macraea laricifolia shrubs, few Chiococca alba and Scalesia microcephala , among lava boulders and outcrops, on rock, 16- Nov-2007, Bungartz, F. 7814 ( CDS 38323); 0˚13’43.27’’ S, 91˚19’47.27’’W, 724 m alt., transition zone, SW-exposed lava flow of weathered AA-lava with scarce vegetation ( Macraea laricifolia , Dodonaea viscosa , Croton scouleri , Cordia revoluta and Jasminocereus thouarsii ), on rock, 12-Nov-2007, Bungartz, F. 7413 ( CDS 37900), 7426 ( CDS 37913); Ertz, D. 11803 ( CDS 37162); 0˚13’28.19’’ S, 91˚19’17.89’’W, 872 m alt., transition zone, lava flow among open scrubland of Croton scouleri and Dodonaea viscosa with Cordia revoluta and some Opuntia insularis , overhang, on rock, 15-Nov-2007, Ertz, D. 11956 ( CDS 37315); ca. 1.5 km from the southwestern crater rim, 0˚12’20.5’’ S, 91˚18’52.77’’W, 1280 m alt., high altitude dry zone, basalt outcrop bare of vegetation, on rock, 14-Nov-2007, Ertz, D. 11876 ( CDS 37235), 11888 ( CDS 37247), 11878 A ( CDS 38894); 0˚13’25.60’’ S, 91˚19’13.80’’W, 900 m alt., transition zone, top of lava flow of weathered AA-lava with scarce vegetation ( Jasminocereus thouarsii , Dodonaea viscosa , Chiococca alba , Macraea laricifolia ), on rock, 15-Nov-2007, Bungartz, F. 7775 ( CDS 38283); Caleta Negra at the W-coast of the island, 0˚14’43.10’’ S, 91˚23’10.4’’W, 1 m alt., coastal zone, W-exposed lava flow of weathered AAlava, on rock, 17-Nov-2007, Bungartz, F. 7964 ( CDS 38474). Volcán Sierra Negra, along dirt road from Puerto Villamil to crater of Sierra Negra, 0˚55’12.4’’ S, 90˚59’38.20’’W, 30 m alt., dry zone, SW-slope of old lava flow with scattered vegetation ( Bursera graveolens , Opuntia echios , and Waltheria ovata ), on rock, 10-Sep-2007, Bungartz, F. 6937 ( CDS 36437), 6957 ( CDS 36461), 6959 ( CDS 36463), 7069 ( CDS 37550); Muro de las Lagrimas W of Puerto Villamil, along the stairs going up behind the wall, 0˚57’52.70’’ S, 91˚0’46.77’’W, 78 m alt., dry zone, dry zone vegetation with Bursera graveolens and Opuntia echios , slope 45° N, E side of basaltic rocks at the side of the stairs (exposed), on rock, 17-Aug-2008, Truong, C. 1257 ( CDS 39568); Herrera-Campos, M.A. 10736 ( CDS 40474); close to Volcán Chico, along the trail, 0˚46’57.77’’ S, 91˚5’59.39’’W, 944 m alt., transition zone, dry and rocky area (young lava), with cacti and Macraea laricifolia , slope 40° NE, basaltic rocks, on rock, 14-Aug-2008, Clerc, P. 08-144 ( CDS 39998), 08-150 ( CDS 40004), 08-151 ( CDS 40005); Volcán Chico on the norteastern slope of Sierra Negra, 0˚46’56.77’’ S, 91˚6’4.298’’W, 938 m alt., transition zone, young lava flow with very scattered vegetation ( Macraea laricifolia , Darwiniothamnus tenuifolia ), on rock, 14-Aug-2008, Bungartz, F. 8172 ( CDS 40818), 8180 ( CDS 40826); top of the northern crater rim, 0˚48’3’’ S, 91˚5’25.89’’W, 968 m alt., humid zone, SW-exposed basalt cliffs among dry vegetation of grasses and herbs, on rock, 08-Sep-2007, Bungartz, F. 6777 ( CDS 36196), 6783 ( CDS 36202).

Figures

FIGURE 10. Species in the L. subfusca-group; superficially similar species with pale apothecial disc and pulicaris-type exciple (large crystals only). A–B. Lecanora achroa (Nugra, F. 111, CDS 32765). A. Thick rimose-areolate, white thallus with lecanorine apothecia with pale brown discs, growing on smooth bark of Bursera. B. Apothecial section with chlarotera-type epihymenium and pulicaris-type exciple. C–D. Lecanora leprosa. C. White, dispersed thallus granules on whitish prothallus with lecanorine apothecia with pale yellowish green discs, on smooth bark of Bursera (Bungartz, F. 6319, CDS 34534). D. Apothecial section with chlarotera-type epihymenium and pulicaris-type exciple (Bungartz, F. 6039, CDS 33718). E–F. Lecanora sulfurescens. E. White thallus with lecanorine apothecia with pale brown discs, growing on rock (Bungartz, F. 4054, CDS 27984). F. Apothecial section with pulicaris-type epihymenium and pulicaris-type exciple (Bungartz, F. 6562, CDS 34780). Scales: A, C, & E = 5 mm; B, D & F = 100 µm.

FIGURE 11. Species in the L. subfusca-group; superficially similar species with brown apothecial disc and pulicaris-type exciple (large crystals only). A–C. Ecological thallus variation of Lecanora sulfurescens. A. Scantly developed, thin thallus with net-like areoles, apothecia with pale greenish yellow disc; developed below shaded overhang on coarse lava (Bungartz, F. 4386, CDS 28471). B. Thallus of minute, scattered, isolated, granular areoles, apothecial disc chestnut brown; growing on strongly weathered rock with ±disintegrating mineral surface (Bungartz, F.6416, CDS 34631). C. Smooth, contiguous areolate thallus delimited by blackened prothallus line, apothecial disc chestnut brown; growing on smooth basalt surface (Bungartz, F. 4822, CDS 28988). D.–F. Lecanora galactiniza. D. Exuberant, thick areolate thallus with marginal areoles becoming subsquamulose, apothecial disc chestnut brown; growing at a nutrient-rich site (Bungartz, F.4706, CDS 28804). E. Thallus of discrete, dispersed squamules, apothecial disc dark brown; growing on coarse, irregular lava (Bungartz, F. 5207, CDS 29420). F. Section of apothecium with pulicaris-type exciple (with large crystals only) and pulicaris-type epihymenium (deep brown pigment not dissolving, but minute crystals dissolving in KOH; in KOH, DIC). Scales: A–E = 5 mm; F = 100 µm.