Lecanora prosecha Ach. (1810: 346) 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 : 15-17

Lecanora prosecha Ach. (1810: 346) MycoBank no. 389041

Type:— FRANCE. TERRITORIAL COLLECTIVITY OF SAINT-BARTHÉLEMY, exact locality unknown, original label data: “ Habitat ad saxa in insulae Sti Bartolomaei Ind. Occid. ” (= living on rock on St. Barthelemy Island , West Indies), without date, Forström, F. s.n. (H-Ach

1173–material cited by Elix & Øvstedal 2007; probably needs lectotypification). ( Fig. 4A–F )

Thallus saxicolous, thick, contiguous, barely rimose, fissures with undulating to ±crenate, interlocked edge, eventually merging, and, when well developed forming distinct, closely interlocked areoles; surface pale grey with a pinkish beige tan, dull, epruinose, in parts occasionally ±oxidized (with a pale ‘rust-red’ dust); soralia pustulate, with coarsely granular, pale white to very faintly pale green soredia, when eroded leaving circular, crateriform scars; margin distinct, flexuous, compact, not delimited by a distinct prothallus. Apothecia sparse to numerous, circular, 0.1–1 mm in diam., cryptolecanorine, immersed, not emerging, with a plane to slightly depressed, epruinose disc, margin not or barely differentiated from the surrounding thallus; hymenium hyaline, not inspersed, epihymenium lacking crystals, with a diffuse reddish brown pigment (arnoldiana -brown: K+ dull brown, HCl+ reddish brown, N−), pigment persistent in K (glabrata - type); proper exciple thin, rarely moderately developed and then with diffuse reddish brown pigment (arnoldiana -brown), with few crystals; thalline exciple barely differentiated from surrounding thallus, with few large crystals that do not dissolve in K (± pulicaris - type); hypothecium hyaline to pale yellowish (intensifying in K); ascospores 8/ascus, simple, ellipsoid, (6.9–)9.2–12.0(13.7) × (3.9–)4.4–5.9(–6.9) µm (n = 48). Pycnidia not seen.

Chemistry: Cortex P+ yellow, K+ yellow, KC–, C–, UV± dull orange, soredia & medulla P+ yellow, K+ yellow, KC+ orange, C+ orange, UV± bright orange (difficult to see); with atranorin [major], arthothelin [major], skyrin [minor], zeorin [minor], ±demethylchodatin [minor], ±4,5-dichloronorlichexanthone [trace]; [specimens analyzed with TLC: Bungartz, F. 3408 ( CDS 27114), 3566 ( CDS 27365), 5633 ( CDS 33258), 6968 ( CDS 36472), 9547 ( CDS 46830), 5108 ( CDS 29321); Clerc, P. 08-276 ( CDS 40130)].

Ecology and distribution: Reported from the Caribbean (French Antilles) by Øvstedal & Elix (2007), new to Ecuador and the Galapagos, frequently growing with L. legalloana , L. subimmersa and Caloplaca diplacia , in similar habitats.

Notes: Fertile specimens of L. prosecha closely resemble L. legalloana and L. subimmersa ssp. subimmersa , but the thallus contains xanthones and the medulla reacts distinctly C+/KC+ orange. Lecanora subimmersa ssp. ramboldii contains thiophanic acid in addition to arthothelin. These three taxa are also esorediate. In the Galapagos thalli of L. prosecha frequently lack apothecia but are then abundantly sorediate, only rarely specimens with both apothecia and soredia can be found. Lecanora prosecha has whitish, cream-colored soredia very similar to those of L. austrosorediosa , but reacting distinctly C+/KC+ orange. Soredia of Caloplaca diplacia or L. avium are also structurally similar, but typically tinged bluish black; both species lack xanthones (C–/KC–).

Specimen examined with both soredia and apothecia. ECUADOR. GALÁPAGOS: San Cristóbal, trail to Cerro Mundo from the border of the National Park, NE of Puerto Baquerizo Moreno, 0˚53’33.39’’ S, 89˚34’42.5’’W, 157 m alt., transition zone, dry bed of periodical stream with lava boulders, abundant Hippomane mancinella and few Bursera graveolens trees, on rock, 25-Aug-2008, Bungartz, F. 8675 ( CDS 41321).

Specimens examined; fertile material lacking soredia. ECUADOR. GALÁPAGOS: Floreana, at bottom of Cerro Asilo de la Paz, along trail to Pampa Larga, 1˚19’8.096’’ S, 90˚27’22.39’’W, 300 m alt., transition zone, cliff of lava tuff in young Scalesia pedunculata forest with Croton scouleri and Zanthoxylum fagara , on rock, 13-Jan-2011, Bungartz, F. 9509 ( CDS 46791); San Cristóbal, 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. 6563 ( CDS 34781); 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. 6636 ( CDS 34856). Santa Cruz, at the bottom of the crater at Camote, 0˚38’10’’ S, 90˚17’37’’W, 298 m alt., humid zone, open flat area with herbs, scattered basalt boulders, trees and shrubs ( Psidium galapageium , Cestrum auriculatum , Zanthoxylum fagara , Croton scouleri ), on rock, 19-Feb-2007, Bungartz, F. 5633 ( CDS 33258).

Sorediate material lacking apothecia. ECUADOR. GALÁPAGOS: Floreana, along trail going to Post Office Bay off the dirt road between highlands and Puerto Velasco Ibarra, at Laguna Seca, 1˚15’30.80’’ S, 90˚26’26.60’’W, 206 m alt., dry zone, very open Bursera graveolens forest over SE-exposed lava flow with Prosopis juliflora , on rock, 14-Jan-2011, Bungartz, F. 9547 ( CDS 46830); 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. 9610 ( CDS 46889). San Cristóbal, Cerro Colorado summit, around the viewpoint, 0˚54’54.89’’ S, 89˚26’1.5’’W, 159 m alt., dry zone, dry zone vegetation with Croton scouleri , Cordia lutea and Macraea laricifolia , basalt rocks, slope 15° SWW, on rock, 24-Aug-2008, Clerc, P. 08-276 ( CDS 40130). Santa Cruz, along the S coast of Santa Cruz close to the Charles Darwin Research Station ( CDRS), Puerto Ayora, 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. 3408 ( CDS 27114); along the road from Bellavista to El Garrapatero, ca. 2 km from the coast, at the campsite of the National Park, 0˚41’25’’ S, 90˚13’35’’W, 24 m alt., dry zone, deciduous dry lowland forest, Bursera graveolens , Acacia rorudiana , Opuntia echios , Croton scouleri , top of basalt boulder; sunny, wind- and rain exposed, on rock, 14-Feb-2006, Bungartz, F. 3566 ( CDS 27365); 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. 63295 ( CDS 30035); 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. 63084 ( CDS 29812). Santiago, ca. 7 km inland from the E-coast, ± at the same latitude as Bahía Sullivan, 0˚17’4’’ S, 90˚38’21’’W, 19dry zone, scrubland of Castela galapageia and Macraea laricifolia with occasional trees of Bursera graveolens , Zanthoxylum fagara and Psidium galapageium on NE-exposed slope, top and slope of SW-exposed small basalt rock; shaded, on rock, 17-Jul-2006, Bungartz, F. 5108 ( CDS 29321); area around the entrance of the lava tunnel at La Central, 0˚14’23’’ S, 90˚45’8’’W, 667 m alt., humid zone, vertical cliffs around the entrance of the lava tunnel overgrown by ferns ( Nephrolepis pectinata , Blechnum occidentale , Thelypteris hispidula , T. conspersa , Megalastrum pleiosorus , Tectaria aequatoriensis , and Trichomanes reptans ), on rock, 24-Mar-2006, Bungartz, F. 4848 ( CDS 29024). Isabela, 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, at bottom of old lava flow with scattered vegetation ( Bursera graveolens , Opuntia echios , and Waltheria ovata ), on bark, 10-Sep-2007, Bungartz, F. 6968 ( CDS 36472); Muro de las Lagrimas, ca. 5 km W of Puerto Villamil, 0˚57’52.70’’ S, 91˚0’46.77’’W, 78 m alt., dry zone, SE-exposed wall of basalt boulders, on rock, 17-Aug-2008, Bungartz, F. 8438 ( CDS 41084).

Figures

FIGURE 4. Species in the L. marginata-group. A–F. Lecanora prosecha. A–B. Esorediate specimen (Bungartz, F. 5633, CDS 33258). A. Thallus of distinctly crenate areoles with deeply immersed, cryptolecanorine, dark reddish-brown to blackened apothecia. B. Apothecial section (in water, DIC): exciple indistinct from surrounding thallus, epihymenium pale brown. C–F. Morphological variation of sorediate thalli. C. General growth aspect of the rimose, pale pinkish gray thallus (Bungartz, F. 6968, CDS 36472–holotype). D. Close-up of thick rimose pale pinkish gray thallus with sublobate margins, pustulate soralia with coarsely granular whitish to pale green soredia (Bungartz, F. 8675, CDS 41321). E. Sorediate thallus with immersed, cryptolecanorine apothecia (Bungartz, F. 8675, CDS 41321). F. Rimose pale gray thallus in parts tinged by reddish iron-oxides, pustulate soralia mostly eroded, leaving circular scars (Bungartz, F. 4848, CDS 29024). Scales: A, C, D, E & F = 5 mm; B = 100 µm.