Lecanora schindleri Guderley (1999: 227) 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 : 54

Lecanora schindleri Guderley (1999: 227) MycoBank no. 460019

Type:— ECUADOR. GALAPAGOS: Floreana, lava flow near the shore just north of Black Beach , on Bursera graveolens , 24-Apr-1976, Weber, W.A. s.n. & Lanier, J. (L-62983, COLO 294539– holotype!) .

( Fig. 12A–B )

Thallus corticolous, thin to moderately thickened, rimose to rimose-areolate, areoles granular to densely verrucose or bullate; surface white to pale gray, roughened, matt, epruinose or with very faint, whitish pruina, lacking soredia; prothallus faintly developed, powdery arachnoid to compact, generally white, but occasionally blackening and often forming a line where different thalli meet. Apothecia numerous, often densely aggregated, circular to slightly irregular in outline, often deformed by mutual pressure, 0.4–1.4 mm in diam., adnate to soon sessile and then ±constricted, distinctly lecanorine with a persistent, entire to weakly undulating, smooth, crenate or strongly verruculose, epruinose to weakly whitish pruinose margin, concolorous with the thallus; disc plane to ±convex, deep mahogany brown, epruinose to faintly whitish pruinose; hymenium hyaline, not inspersed; epihymenium with crystals, with a diffuse reddish brown pigment (arnoldiana -brown: K+ dull brown, HCl+ reddish brown, N−), crystals dissolving in K, pigment persistent (pulicaris - type); proper exciple thin, indistinct, with abundant small crystals dissolving in K; thalline exciple thick, distinctly corticate, with many small crystals that obscure few larger ones, often visible only when the small crystals are dissolved in K, but the large ones persist (melacarpella - type); hypothecium hyaline; ascospores 8/ascus, simple, ellipsoid to broadly ellipsoid, (8.9)–9.6–11.3–(11.9) × (5.9–)6.5–7.1(–6.9) µm (n = 45). Pycnidia not seen.

Chemistry: Thallus cortex including apothecial margin P+ yellow, C−, KC−, K+ yellow; with atranorin [major], 20α-acetoxyzeorin [major]; [specimens analyzed with TLC: Herre, A.W.C.T. 57 (L-41173, COLO 195077; Bungartz, F. 7674 ( CDS 38177)].

Ecology and distribution: Endemic to the Galapagos ( Guderley 1999); a common species throughout the dry and lower transition zone, rarely also found in the humid zone and few collections from the high altitude dry zone, on bark of native and endemic trees and shrubs ( Bursera , Clerodendrum molle , Croton scouleri , Piscidia carthagenensis , Psidium galapageium , Scalesia microcephala ).

Notes: Superficially L. schindleri is very similar to L. tropica , but differs in its exciple anatomy. The exciple of both species contains both large and small crystals, but only the small crystals are soluble in K. In L. schindleri the large crystals are not seen initially, being obscured by large amounts of small crystals; the large crystals only become visible once the small ones have been dissolved with K (melacarpella - type). This contrasts with the exciple of L. tropica , which has abundant large crystals that are readily observed, only rarely interspersed, but not obscured, by a few smaller crystals (pulicaris - type).

The two species can further be distinguished by their epihymenia. In L. schindleri small crystals are present; they dissolve in K. Lecanora tropica lacks epihymenial crystals. Both species have the same reddish brown pigment, which persists but fades in K to a dull brown and in HCl turns faint reddish brown again. According to Guderley (1999) this pigment does not dissolve. Following the protocol outlined in Meyer & Printzen (2000) the pigment is nevertheless eventually washed out, especially if 20% KOH and 10% HCl are successively applied. The two species are apparently also distinguished by their spores, though these differences are less obvious; spores are generally smaller and more broadly ellipsoid in L. schindleri compared to those of L. tropica .

Specimens examined. ECUADOR. GALÁPAGOS: Floreana, Post Office Bay, 15-Jan-1929, Herre, A.W.C.T. 57 (L-41173, COLO 195077, CAS-DS 508274); trail from Black Beach to highlands, Bursera , on bark, 25-Apr-1976, Weber, W.A. s.n. (L-62930, COLO 294592); at Punta Cormorant, dry zone, cinder cone slope, Bursera , on bark, 23- Apr-1976, Weber, W.A. s.n. (L-63003, COLO 291548); San Cristóbal, along the trail from Galapagera at the NW-coast of the island to Media Luna, 0˚42’41’’ S, 89˚18’15’’W, 33 m alt., dry zone, open woodland of Piscidia carthagenensis , Bursera graveolens , and Gossypium darwinii shrubs, on trunk of Piscidia carthagenensis , 22-Apr-2007, Bungartz, F. 6323 ( CDS 34538); SW foothills of Media Luna, inland from the NW-coast of the island along the trail from Galapagera to Media Luna; bottom of small crater to the NW of Media Luna, 0˚43’53’’ S, 89˚18’57’’W, 124 m alt., dry zone, upper dry zone; woodland of Piscidia carthagenensis , Cordia lutea , Zanthoxylum fagara , Croton scouleri and few Bursera graveolens , on base of Bursera graveolens trunk, 22-Apr-2007, Bungartz, F. 6272 ( CDS 34480); road leading out of Wreck Bay, Bursera , on bark, 20-May-1976, Lanier, J. s.n. (L-63724, COLO 298455). Santa Cruz, on bark of Bursera, Hill, T. s.n. ( FH-TUCK 197149); vicinity of Academy Bay, on bark of Bursera , 15-Feb-1964, Weber, W.A. s.n. (L-40337, COLO 188861); 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 , Bursera , on bark, 14-Feb-2006, Aptroot, A. 63965 B ( CDS 30525); 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 , on branches of Bursera graveolens , 23-Feb-2006, Bungartz, F. 3909 ( CDS 27791). Santiago, along the trail from the caseta in La Central to La Bomba (at the coast), 0˚12’54’’ S, 90˚43’21’’W, 293 m alt., dry zone, open woodland of Bursera graveolens and Opuntia galapageia with shrubs of Castela galapageia and Clerodendrum molle among basalt boulders and rocks, on twigs of Clerodendrum molle , 25-Mar-2006, Bungartz, F. 4936 ( CDS 29140); 0˚13’41’’ S, 90˚44’9’’W, 528 m alt., transition zone, open woodland of Psidium galapageium , Zanthoxylum fagara , Bursera graveolens , Trema micrantha and Opuntia galapageia with shrubs of Clerodendrum molle in between, on branches of Pisonia floribunda , 25-Mar-2006, Bungartz, F. 4887 ( CDS 29091); along the trail from Bucanero to Jaboncillos, 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 trunk of Bursera graveolens , 22-Mar-2006, Bungartz, F. 4668 ( CDS 28755); Aptroot, A. 65422 ( CDS 32008); 4 km E of the eastern summit, 0˚13’15’’ S, 90˚44’30’’W, 645 m alt., transition zone, open Bursera - Zanthoxylum forest, Bursera , on bark, 06-May-1971, Pike, L.H. ID28-24 (0, OSC 99472). Volcán, Alcedo Isabela, in the crater near fumaroles, 0˚27’1’’ S, 91˚7’19’’W, 780 m alt., transition zone, mostly Bursera graveolens and dense scrub on uneven lava, Bursera , on bark, 07-Mar-2006, Aptroot, A. 64788 ( CDS 31363); cinder cones along the trail going up the E-slope, 0˚23’40’’ S, 91˚1’18’’W, 190 m alt., dry zone, basalt outcrops, at the bottom scattered Bursera graveolens trees and shrubs of Castela galapageia , on trunk of Bursera graveolens , 10-Mar-2006, Bungartz, F. 4484 ( CDS 28570); outer SE-exposed slope and crater rim, 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 trunk of Croton scouleri , 05-Mar-2006, Bungartz, F. 4075 ( CDS 28005); along the trail going up the E-slope, basalt rubble field to the SE-side of the trail and the barranco, 0˚24’3’’ S, 91˚2’35’’W, 434 m alt., dry zone, basalt rubble field with scattered vegetation ( Bursera graveolens , Zanthoxylum fagara , Pisonia floribunda , Senna pistaciifolia ), on branches of Pisonia floribunda , 09-Mar-2006, Bungartz, F. 4412 ( CDS 28497). Volcán Darwin, at the W-coast between Tagus Cove and Caleta Negra, ca. 1 km inland from the coast, 0˚14’50.89’’ S, 91˚22’43.77’’W, 55 m alt., dry zone, open Bursera graveolens forest on NW-exposed slope with Scutia spicata , Castela galapageia and Waltheria ovata , on W-exposed trunk of Bursera graveolens ; 17-Nov-2007, Bungartz, F. 7940 ( CDS 38450); 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, Bursera graveolens , on bark, 16-Nov-2007, Ertz, D. 11999 ( CDS 37358); Bungartz, F. 7833 ( CDS 38342), 7846 ( CDS 38355), 7847 ( CDS 38356), 7850 ( CDS 38359); 0˚13’57.89’’ S, 91˚20’5.096’’W, 613 m alt., transition zone, transition zone; SW-exposed lava flow of weathered AA-lava with scarce vegetation ( Macraea laricifolia , Croton scouleri , Dodonaea viscosa , Scalesia microcephala , Cordia revoluta and Opuntia insularis ), on branches of Croton scouleri , 12-Nov-2007, Bungartz, F. 7398 B ( CDS 44203); 0˚13’27.60’’ S, 91˚19’21.19’’W, 860 m alt., transition zone, open scrubland of Dodonaea viscosa , Croton scouleri , Macraea laricifolia , Scalesia microcephala , few Opuntia insularis and dry grasses in the understory, on stem and branches of Croton scouleri , 15-Nov-2007, Bungartz, F. 7674 ( CDS 38177), 7694 ( CDS 38197); 0˚12’11.5’’ S, 91˚18’41.27’’W, 1286 m alt., high altitude dry zone, open forest of Scalesia microcephala , few trees of Zanthoxylum fagara , Cordia revoluta and Croton scouleri shrubs, many young Scalesia in the understory, on stem of Croton scouleri , 13-Nov-2007, Bungartz, F. 7501 ( CDS 37992); ca. 1 km from the southwestern crater rim, 0˚12’20.5’’ S, 91˚18’52.77’’W, 1276 m alt., high altitude dry zone, dense young Scalesia microcephala forest with few trees of Zanthoxylum fagara , on twigs of Scalesia microcephala , 13-Nov-2007, Bungartz, F. 7573 ( CDS 38067), 7574 ( CDS 38068).

Figures

FIGURE 12. Species in the L. subfusca-group; superficially similar species with deep brown apothecial disc and pulicaris-type exciple (large crystals only). A–B. Lecanora schindleri (Weber, W. A. s.n., L-40337, COLO 188861). A. Thallus continuous to barely rimose with fimbriate whitish prothallus, apothecia adnate to sessile, margin entire, disc deep reddish brown to almost blackish brown, epruinose or with very faint, whitish pruina. B. Apothecial section (in water, DIC), exciple with abundant minute, soluble crystals obscuring few large, insoluble ones (melacarpella-type), epihymenium with reddish brown, insoluble pigment and minute soluble crystals (pulicaris-type). C– D. Lecanora tropica. C. Thallus rimose-areolate, slightly verrucose, delimited by a darkened prothallus line, apothecia adnate to sessile, margin entire to ±crenulate, disc deep reddish brown, epruinose (Bungartz, F. 8425, CDS 41071). D. Apothecial section (in water, DIC): exciple with conspicuous, large, insoluble crystals and few minute, soluble ones (pulicaris-type), epihymenium with insoluble brown pigment, lacking crystals (glabrata-type) (Dawson, E.Y. s.n., L-40089, COLO 188062). E–F. L. subimmergens (Bungartz, F. 7600, CDS 38096). E. Thallus areolate, apothecia adnate to sessile, margin entire, slightly undulate, disc dark reddish to blackish brown, epruinose. F. Apothecial section (in water, DIC): exciple with conspicuous, large, insoluble crystals and few minute, soluble ones (pulicaris-type), epihymenium with insoluble brown pigment, lacking crystals (glabrata-type). Scales: A, C & E = 5 mm; B, D & F = 100 µm.