Lecanora cerebrosorediata Aptroot & Bungartz, 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 : 28-29

Lecanora cerebrosorediata Aptroot & Bungartz sp. nov. MycoBank no. 833370

Diagnosis. A pale yellowish green to yellowish white, densely pruinose, continuous crust, that, when well developed, forms conspicuously cerebriform thalli with abundant pulvinate-pustulate soralia, rarely forming apothecia; containing usnic acid and abundant terpenes (forming a ‘fur’ of crystals with storage), occasionally also with xanthones.

Type:— ECUADOR. GALAPAGOS: San Cristóbal, Cerro Partido along trail from entrance to Cerro Pelado to El Ripioso, 0˚51’23’’ S, 89˚27’37’’W, 376 m alt., transition zone, rocky SW-exposed slope of hill with Jasminocereus thouarsii , Clerodendrum molle var. glabrescens , Psidium galapageium , Bromeliaceae and ferns growing in rock crevices, on W-exposed front of basalt boulder, 28-Apr- 2007, Bungartz, F. 6596 ( CDS 34816– holotype).

( Figs. 7A , 9A–D )

Thallus saxicolous, contiguous, not distinctly fissured, uneven to verrucose (‘lumpy’), thin to markedly thickened and then convoluted, gnarled, soon becoming conspicuously cerebriform, particularly in the center i.e., with conspicuously inflated, swollen and convoluted protuberances, which may be dispersed or merge into a very thick crust; surface pale yellowish green to yellowish white, dull, with a coarse, yellowish green pruina (with prolonged storage developing a fine fur of whitish terpenoid needles, appearing moldy), soralia abundant, pulvinate-pustulate, with farinose, bright greenish yellow soredia, sometimes confluent and covering the entire thallus; prothallus absent. Apothecia very rarely present, sparse, circular or slightly undulate in outline, 0.6–1.5(–1.8) mm in diam., adnate to sessile, distinctly lecanorine with a yellowish pruinose, ±crenate margin soon disintegrating into soredia, concolorous with the soredia and/or thallus; disc plane to barely convex, greenish beige, densely whitish pruinose; hymenium hyaline, not inspersed, epihymenium with a diffuse, dull brown pigment (elachista -brown: dissolving in K, HCl± dull greenish, N−) and few to abundant minute crystals, mostly dissolving in K (residue of fine, rounded, reddish granules persistent, 0.5–1 µm); proper exciple thin, indistinct, with few small crystals; thalline exciple densely filled with small crystals that entirely dissolve in K; subhymenium and hypothecium hyaline; asci clavate, Lecanora - type, ascospores 8/ascus, simple, narrowly to broadly ellipsoid, (3.9–)4.1–5.2(–5.9) × (6.9–)8.2–11.8(–13.7) µm (n = 30). Pycnidia not seen.

Chemistry: Thallus cortex including apothecial margin P−, C– or C+ orange, KC– or KC+ orange, K± yellowish brown, UV− (dull); usnic acid [major], ±arthothelin [major], zeorin [major], ±leucotylin [minor], unknown terpenes [minor or traces]; [specimens analyzed with TLC: Aptroot, A. 64123 ( CDS 30685); Bungartz, F. 4794 ( CDS 28926), 5389 ( CDS 29605), 6564 ( CDS 34782), 6724 ( CDS 34968), 7133 ( CDS 37618)].

Etymology: Like L. cerebriformis described above, the epithet cerebrosorediata refers to the unusually convoluted, brain-like growth form as well as the presence of soredia.

Ecology and distribution: Known only from the Galapagos, a common saxicolous species, particularly frequent in coastal, dry and transition zone vegetation, less common in the humid zone, typically growing in exposed, sunny, occasionally ±sheltered habitats.

Notes: Because of its cerebriform growth, this species could be considered a yellowish, sorediate counterpart of the white L. cerebriformis and containing usnic acid rather than protocetraric acid. The cerebriform growth of these two not necessarily closely related species might be the result of an adaptation to a habitat as the two species are often found growing together. The most exuberant thalli of both species are frequently encountered in humid habitats (shaded cliffs, sheltered fronts and overhangs of large boulders; Fig. 7A ). Thalli of L. cerebriformis lacking conspicuous protuberances are rare, but rimose thalli of L. cerebrosorediata are fairly common. They typically grow in drier, more exposed sites. These specimens were initially believed to be a distinct species, but intermediates do occur and the two forms are chemically identical, predominantly producing usnic acid but occasionally additional xanthones.

Additional specimens examined (paratypes). ECUADOR. GALÁPAGOS: Española, trail from Bahía Manzanillo on the N-coast of the island to the highest point, 1˚21’24.89’’ S, 89˚41’57’’W, 24 m alt., dry zone, boulder field of weathered AA-lava with scarce vegetation of Ipomoea habeliana , one Bursera tree and few Cordia lutea shrubs, on rock, 11-Nov-2010, Yánez-Ayabaca, A. 1661 ( CDS 45544), 1656 ( CDS 45539); Bungartz, F. 8980 B ( CDS 56101), 9002 ( CDS 45820), 9005 ( CDS 45823); 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 , on rock, 10-Nov-2010, Bungartz, F. 8931 ( CDS 45749). Floreana, along rim trail of Cerro Pajas, northeastern part of rim, 1˚17’40.20’’ S, 90˚27’17.30’’W, 504 m alt., humid zone, low dense vegetation of Zanthoxylum fagara , Scalesia pedunculata , Macraea laricifolia , Croton scouleri and ferns ( Polypodium tridens ) over lava boulders; bryophytes hanging in curtains from trees, on rock, 26-Jan-2011, Bungartz, F. 10277 ( CDS 47696); lava flow ca. 200 m N of village Puerto Velasco Ibarra, at the W-coast of the island, ca. 100 m inland, 1˚16’10.1’’ S, 90˚29’17.80’’W, 11 m alt., coastal zone, lava flow of weathered AA-lava with scarce vegetation, mostly Mentzelia aspera , shrubs of Lecocarpus pinnatifidus , some Waltheria ovata and occasional Jasminocereus thouarsii , on rock, 18-Jan-2011, Bungartz, F. 9876 B ( CDS 49563), 9873 ( CDS 47211); inside the crater of Cerro Laguna at E-side of island, on Wexposed slope, 1˚16’11.80’’ S, 90˚23’17’’W, 245 m alt., transition zone, dense forest of Prosopis juliflora , Clerodendrum molle , very few Bursera graveolens and some Jasminocereus thouarsii in the upper part among lava outcrops and boulders; Ramalina usnea /anceps hanging in curtains from Clerodendrum twigs, on rock, 20-Jan-2011, Bungartz, F. 9979 ( CDS 47348); 9966 ( CDS 47335); ca. 500 m S of La Lobería, ca. 200 m inland from coast, 1˚17’12.69’’ S, 90˚29’36’’W, 20 m alt., dry zone, very open Bursera forest with Waltheria ovata , few Scalesia affinis and some grasses on lava flow, on rock, 16-Jan-2011, Bungartz, F. 9760 ( CDS 47077); trail going to Post Office Bay off the dirt road between highlands and Puerto Velasco Ibarra, 1˚15’42.27’’ S, 90˚26’31’’W, 197 m alt., dry zone, open forest of Bursera graveolens and some Prosopis juliflora on W-exposed slope, dry herbaceous vegetation and small boulder field, on rock, 14-Jan-2011, Bungartz, F. 9614 ( CDS 46893); 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. 10209 ( CDS 47628). Pinta, N-exposed slope of highest point of the island, at crater rim, 0˚35’6’’N, 90˚45’10’’W, 620 m alt., humid zone, dense vegetation of ferns and low shrubs, on rock, 26-Feb-2007, Bungartz, F. 5752 ( CDS 33407); 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 rock, 01-Mar-2007, Bungartz, F. 6063 ( CDS 33742). 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. 64099 ( CDS 30660); along the trail going up from Playa Escondida, 0˚36’10’’ S, 90˚40’1’’W, 254 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. 64119 A ( CDS 30680), 64122 ( CDS 30684), 64123 ( CDS 30685); 0˚36’9.096’’ S, 90˚39’59.39’’W, 247 m alt., dry zone, open Cordia lutea scrub with Croton scouleri , Prosopis juliflora , Maytenus octogona and Alternanthera filifolia over lava boulders, on rock, 22-Jun-2009, Bungartz, F. 8748 ( CDS 44430); N- to W-facing cliff above a crater, 0˚36’29’’ S, 90˚40’14’’W, 318 m alt., transition zone, dry transition zone with Cordia lutea , Croton scouleri , and at the bottom of the cliff also Scalesia baurii ssp. baurii , lava, on rock, 16-Feb- 2006, Aptroot, A. 64011 ( CDS 30572); 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. 3600 ( CDS 27418). Rábida, NW-side of Rábida, 0˚23’59’’ S, 90˚42’35’’W, 27 m alt., dry zone, on top of coastal cinder cliff above the beach; N-exposed slope with lava boulders, rocks and young Bursera graveolens trees (max. 3 m in height), NNW-exposed front of small basalt rock, on rock, 21-Jul-2006, Bungartz, F. 5357 ( CDS 29573). San Cristóbal, from Punta Tortuga ca. 3 km inland close to Cerro Tortuga, 0˚44’39’’ S, 89˚23’32’’W, 79 m alt., dry zone, young basalt lava flow of bare AA-lava, on rock, 25-Apr-2007, Bungartz, F. 6492 ( CDS 34709), 6502 ( CDS 34719); 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. 6099 ( CDS 33778); rim of crater to the NW of Media Luna, inland from the NW-coast, 0˚43’51’’ S, 89˚18’55’’W, 149 m alt., transition zone, lower transition zone; basalt cliffs of inner and outer crater rim with scarce vegetation, on rock, 22-Apr-2007, Bungartz, F. 6294 ( CDS 34506); Cerro Partido along trail from entrance to Cerro Pelado to El Ripioso, 0˚51’23’’ S, 89˚27’37’’W, 376 m alt., transition zone, rocky SW-exposed slope of hill with Jasminocereus thouarsii , Clerodendrum molle var. glabrescens , Psidium galapageium , Bromeliaceae and ferns growing in rock crevices, on rock, 28-Apr-2007, Bungartz, F. 6645 ( CDS 34865), 6651 ( CDS 34871); Cerro Colorado, enclosure for Calandrinia galapagosa near the viewpoint on the top, 0˚54’58’’ S, 89˚26’5’’W, 13 m alt., transition zone, open scrubland with Croton scouleri , Macraea laricifolia , Calandrinia galapagosa , Lecocarpus darwinii and few trees of Piscidia carthagenensis among lava boulders on SEexposed slope of cinder cone, on rock, 29-Apr-2007, Bungartz, F. 6726 ( CDS 34970), 6724 ( CDS 34968); sector of the “Gotera de agua”, cliffs of Cerro El Partido, 0˚51’25.60’’ S, 89˚27’34.89’’W, 377 m alt., transition zone, basalt rocks, on rock, 23-Aug-2008, Clerc, P. 08-329 ( CDS 40183); 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. 6564 ( CDS 34782); S-slope of Cerro Mundo, shortly below the top; NE of Puerto Baquerizo Moreno and ca. 2.5 km NW of El Progreso, 0˚53’21.60’’ S, 89˚34’25.69’’W, 259 m alt., transition zone, ledge of SE-exposed basalt cliff with some Bursera graveolens trees, Croton scouleri shrubs, Zanthoxylum fagara and few Jasminocereus thouarsii , on rock, 25- Aug-2008, Bungartz, F. 8691 ( CDS 41337). Santa Cruz, Puerto Ayora, near Charles Darwin Research Station ( CDRS), 0˚44’32’’ S, 90˚18’10’’W, 5 m alt., coastal zone, coastal lava, on rock, 24-May-2005, Aptroot, A. 63125 ( CDS 29855); along shore E of Puerto Ayora near Charles Darwin Research Station ( CDRS), 0˚44’45’’ S, 90˚17’39’’W, 20 m alt., coastal zone, coastal lava, on rock, 29-May-2005, Aptroot, A. 63284 ( CDS 30024); 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. 64536 ( CDS 31108); at the East coast of the island, ca. 400 m N of Cerro Colorado, on top of the coastal cliff; E-exposed, 0˚34’47’’ S, 90˚10’21’’W, 21 m alt., dry zone, scattered scrubs of Castela galapageia , Acacia rorudiana , and Opuntia echios among basaltic rocks, a rare Bursera graveolens in between, lava, on rock, 21-Feb- 2006, Aptroot, A. 64363 ( CDS 30928); 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, vertical rock face, on rock, 21-Oct-2007, Ertz, D. 11604 ( CDS 36930); Bungartz, F. 7133 ( CDS 37618); Mina Granillo Rojo , on the N-side of the island, above the the mine, 0˚37’8.80’’ S, 90˚21’57.60’’W, 633 m alt., transition zone, lava outcrop in open forest of Scalesia pedunculata , Psidium galapageium and few Bursera graveolens , on rock, 21-Jan-2010, Bungartz, F. 8759 ( CDS 44640). Plaza Sur (near Santa Cruz), South Plaza Island, 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 , lava, on rock, 21-Feb-2006, Aptroot, A. 64447 ( CDS 31015). 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. 7238 ( CDS 37722); lava flow at the N-coast of the island, 0˚48’2.798’’ S, 90˚2’38.39’’W, 26 m alt., dry zone, open scrubland of Croton scouleri with some Bursera graveolens trees, and Opuntia echios var. barringtonensis on NE-exposed side of lava flow, exposed basalt lava, on rock, 25-Oct-2007, Jonitz, H. 25 B ( CDS 56096); 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. 7197 ( CDS 37681). 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 rock, 22-Jul-2006, Bungartz, F. 5389 ( CDS 29605), 5410 ( CDS 29626); at the W-coast of the island in Bahía Ladilla, 0˚18’8’’ S, 90˚49’56’’W, 10 m alt., coastal zone, NE-exposed lava cliff and boulders, on rock, 22-Jul-2006, Bungartz, F. 5377 ( CDS 29593); ca. 5 km inland from the E-coast, ± at the same latitude as Bahía Sullivan, 0˚16’37’’ S, 90˚37’24’’W, 163 m alt., dry zone, SE-exposed slope of lava boulders, on rock, 18-Jul-2006, Bungartz, F. 5212 ( CDS 29425), 5216 ( CDS 29429); 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 rock, 23-Mar-2006, Aptroot, A. 65719 ( CDS 32311), 65759 ( CDS 32351); Bungartz, F. 4801 D ( CDS 43922), 4800 ( CDS 28932), 4794 ( CDS 28926). Isabela, Volcán Alcedo, highest cinder cone along the trail going up the E-slope, 0˚23’37’’ S, 91˚1’31’’W, 250 m alt., dry zone, basalt outcrops, at the bottom scattered Bursera graveolens trees and shrubs of Castela galapageia , lava, on rock, 10- Mar-2006, Aptroot, A. 65006 ( CDS 31586); Volcán Darwin, southwestern slope, above Tagus Cove, 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. 7809 ( CDS 38318); 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 ), overhang, on rock, 12-Nov-2007, Ertz, D. 11778 ( CDS 37137); 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 AA-lava, on rock, 17-Nov-2007, Bungartz, F. 7959 ( CDS 38469); Volcán Sierra Negra, Las Tintoreras, small island in front of Puerto Villamil at the S-coast of Isabela, 0˚58’13.6’’ S, 90˚57’39’’W, 13 m alt., coastal zone, young lava flow of AAlava bare of vegetation, on rock, 10-Sep-2007, Bungartz, F. 7026 ( CDS 36533); Cerro Orchilla, ca. 4 km W of Puerto Villamil, 0˚57’47.27’’ S, 91˚0’27.19’’W, 56 m alt., dry zone, S exposed slope of hill, open Bursera graveolens forest with Croton scouleri and Opuntia echios , on rock, 17-Aug-2008, Bungartz, F. 8465 ( CDS 41111).

Figures

FIGURE 7. Species in the L. pallida-group. A–D. Morphological variation of Lecanora cerebriformis. A. Mosaic of moderately convoluted, white thalli with apothecia of Lecanora cerebriformis and strongly convoluted sorediate thalli of L. cerebrosorediata with few apothecia (Bungartz, F. 8759, CDS 44640). B. Strongly convoluted, ‘cerebriform’ thallus (Bungartz, F. 5215, CDS 29428). C. Gnarled ‘cerebriform’ thallus (Bungartz, F. 5215, CDS 29428). D. Exuberantly coralloid ‘cerebriform’ thallus (Bungartz, F. 6633, CDS 34853– holotype). Scales: A, B, C & D = 5 mm.

FIGURE 9. Species in the L. pinguis-group. A–D. Morphological variation of Lecanora cerebrosorediata. A.Thallus flattened, continuous to barely rimose (Aptroot, A. 64123, CDS 30685). B. Mosaic of deep yellow rimose-areolate, fertile thalli of L. pseudopinguis mixed with cushions of convoluted, ‘cerebriform’, pale yellow, sorediate L. cerebrosorediata (Bungartz, F. 4800, CDS 28932). C. Thallus distinctly ‘cerebriform’ (Bungartz, F. 5212, CDS 29425). D. Thallus exuberantly coralloid ‘cerebriform’, with few apothecia (Bungartz, F. 6596, CDS 34816–holotype). Scales: A, B, C & D = 5 mm.