Lepraria tenella (Tuck.) Lendemer & Hodkinson (2013: 1006) MycoBank

Bungartz, Frank, Hillmann, Georg, Kalb, Klaus & Elix, John A., 2013, Leprose and leproid lichens of the Galapagos, with a particular focus on Lepraria (Stereocaulaceae) and Septotrapelia (Pilocarpaceae), Phytotaxa 150 (1), pp. 1-28 : 8-16

Lepraria tenella (Tuck.) Lendemer & Hodkinson (2013: 1006) MycoBank no. 806088

Stereocaulon tenellum Tuck. (1862: 123) MycoBank no. 406055

Leprocaulon tenellum (Tuck.) Nyl. (1890: 19) MycoBank no. 393285

Type: — SOUTH AMERICA. PERU: “near Lima, Peru,” ( Wilkes Expedition 1838–1842) [FH– Holotype (non vidi)] .

Taxonomic note: Lendemer & Hodkinson (2013) proposed the new combination as Lepraria tenellum (MycoBank no. 564057), but according to Art. 23.5 of the International Code of Nomenclature for algae, fungi, and plants ( McNeill et al. 2012) the gender of the epithet, if used as an adjective, must follow the gender of the generic name, the epithet is thus corrected here to its female form tenella .

( Figs. 6c–d )

Thallus saxicolous; initially placodioid leprose, i.e., developing upon a common, shared hypothallus (structurally similar to L. vouauxii ), but soon becoming leprose-fruticose by the formation of ill-defined pseudopodetia that lack a distinct axial strand, prothallus fine, inconspicuous, main thallus of distinctly delimited granules, soon budding into branched gnarled, pseudocorticate pseudopodetia; surface white to pale yellowish or grenish ivory white; hypothallus inconspicuous, exposed only as a fine prothallus along the thallus margin; rhizohyphae absent or at least indistinct; granules pseudocorticate, very compact, coarse [(157–)170–185(–200) µm in diam., rather uniform in size], aggregating into erect, coarse (0.8–)3–5(–11.5) mm tall pseudopodetia, without conspicuous extruding hyphae, immature or damaged or eroded parts rarely with few protruding hyphae; photobiont green, coccoid, 7–10 µm in diam.

Spot tests and chemistry: P+ reddish orange, K+ yellow orange, C+ red, KC−; UV−(dark); atranorin, lecanoric acid, pannaric acid 6-methyl ester [other secondary metabolites not confirmed for the Galapagos chemotype, Lamb (1974, table 1) also lists rangiformic and other fatty acids as well as grayanic, divaricatic, evernic, and sekikaic acid].

Distribution and ecology: Neotropical ( Lamb 1974: Chile, Peru), first reported from Galapagos by Weber as Leprocaulon tenellum ; in the archipelago it is rare in the dry and lower transition zone, is most common in the upper transition and humid zone, while a few specimens have even been collected in the high altitude dry zone; it typically grows on rock, rarely on soil and then often overgrowing mosses or detritus, rarely on wood and very rarely on bark. It occurs typically in ±sheltered, shaded habitats, below overhangs or on vertical rock faces and cliffs, rarely in ±exposed situations, but then usually not receiving direct sunlight.

Notes: Elix & McCarthy (1998) suggested that Lepraria tenella might be synonymous with Lepraria albicans (Th.Fr.) Lendemer & Hodkinson (2013: 1005) (≡ Stereocaulon albicans Th.Fr. (1857: 36) . Pseudopodetia of L. tenella are, however, less well defined and consitently lack the central axis of L. albicans . Although both species share some secondary metabolites ( Lamb 1974: table 1), L. tenella appears also well distinguished from L. albicans by the presence of lecanoric acid and dibenzofurans, in particular pannaric acid 6-methyl ester (which, according to Leuckert & Kümmerling 1989 corresponds to the unidentified dibenzofuran LP-1 mentioned by Lamb 1974).

In the Galapagos the only other species with dibenzofurans is L. vouauxii (see below). Both L. tenella and L. vouauxii lack a well defined hypothallus and immature thalli of L. tenella which have not yet developed into pseudopodetia, can be strikingly similar to the coarsely granular thalli of L. vouauxii . Both species have compact, pseudocorticate granules that are largely devoid of extruding hyphae ( Fig. 6 ), although individual granules of L. tenella are generally much larger than those of L. vouauxii . Like many, but not all species of Lepraria s.str. that form pseudopodetia (i.e., species that were previously included in ' Leprocaulon '), the pseudopodetia of L. tenella lack a distinct central, axial strand. This central strand is typical for the type species of Leprocaulon s.str., L. quisquiliare (Leers) M. Choisy (1950: 166) and is also present in the recently described Leprocaulon americanum Lendemer & Hodkinson (2013: 1007) .

Although the species containing dibenzofurans do not form a monophyletic group separate from Lepraria s.str. ( Lendemer & Hodkinson 2013, Lendemer 2013), it nevertheless appears worth investigating whether at least some of these species with structurally similar granules, indistinct hypothalli and no axial strand, are more closely related than others.

Specimens examined. ECUADOR. GALAPAGOS: Fernandina Island, W-side, 335 m alt., transition zone, Cavagnaro, D. s.n. (COLO 193369; L-40461) . Floreana Island, Asilo de la Paz, Cerro Wittmer , trail in between cliffs, 1˚ 18’ 50” S, 90˚ 27’ 13.80” W, 0 m alt., humid zone, on detritus, 03-Jan-2010, Hillmann, G. GAL-94 (CDS 44861) , GAL-103 (CDS 44890) , GAL-102 (CDS 44895) ; highlands along trail from Black Beach, at entrance to finca, 300 m alt., humid zone, 25-Apr-1976, Weber, W.A. s.n. (COLO 291528; L- 63023); 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’ 4.29” S, 90˚ 26’ 36.60” W, 365 m alt., transition zone, on rock, 25-Jan-2011, Bungartz, F. 10186 (CDS 47605) . Pinzón Island, along the trail going up from Playa Escondida , 0˚ 36’ 10” S, 90˚ 40’ 1” W, 254 m alt., dry zone, on wood, 16-Feb-2006, Aptroot, A. 64109 (CDS 30670) ; along the trail going up from Playa Escondida , N- to W-facing cliff above a crater, 0˚ 36’ 29” S, 90˚ 40’ 14” W, 318 m alt., transition zone, on rock, 16-Feb-2006, Aptroot, A. 64034 (CDS 30595) , 64028 B (CDS 43292) , Bungartz , F. 3655 (CDS 27473) . San Cristóbal Island, bordering lake at El Junco, humid zone, on rock, 21-May-1976, Lanier, J. s.n. (COLO 298421; L-63758); Cerro Colorado , enclosure for Calandrinia galapagosa near the viewpoint on the top, 0˚ 54’ 58” S, 89˚ 26’ 5” W, 130 m alt., transition zone, on rock, 29-Apr-2007, Bungartz, F. 6718 (CDS 34962) ; 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, on rock, 28-Apr-2007, Bungartz, F. 6649 (CDS 34869) ; NE-slope of Cerro San Joaquín , shortly below the summit, 0˚ 53’ 50.79” S, 89˚ 30’ 49.70” W, 693 m alt., humid zone, on soil, 24-Aug-2008, Bungartz, F. 8584 (CDS 41230) ; 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, on rock, 22-Apr-2007, Bungartz, F. 6301 (CDS 34513) , 6305 (CDS 34517) ; 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, on rock, 23-Aug-2008, Clerc, P. 08-328 (CDS 40182) ; above the quarry Mina Granillo Rojo , off the main road to the channel, on the N-side of the island, 0˚ 37’ 5.79” S, 90˚ 21’ 59.10” W, 617 m alt., transition zone, on rock, 21-Oct-2007, Ertz, D. 11605 (CDS 36931) ; Maternidad, two craters along road above Santa Rosa (= Los Gemelos ), east crater, N rim, 500 m alt., humid zone, on rock, 17-Jun-1976, Sipman, H.J.M. s.n. (COLO 297954; L-63482); Mina Granillo Rojo , on the Nside of the island, above the the mine, 0˚ 37’ 8.80” S, 90˚ 21’ 57.60” W, 633 m alt., transition zone, on rock, 21-Jan-2010, Jonitz, H. 38 (CDS 44648) ; near Los Gemelos craters, 0˚ 36’ 31” S, 90˚ 22’ 4” W, 350 m alt., humid zone, on rock, 31-May-2005, Aptroot, A. 63375 (CDS 30121) ; on Puntudo , 750 m alt., humid zone, 18- Apr-1976, Weber, W.A. s.n. (CDS 10842) , s.n. (QCA 0); saddle between Mount Crocker and El Puntudo , 775 m alt., humid zone, on rock, 11-Apr-1976, Weber, W.A. s.n. (COLO 297765; L-63671), s.n. (FH 197202) , s.n. (COLO 297009; L-63043). Santiago Island, 2 km E of the eastern peak, 0˚ 13’ 0” S, 90˚ 45’ 0” W, 750 m alt., humid zone, on rock, 06-May-1971, Pike, L.H. 2763 (OSC 70782) ; along the trail from the caseta in La Central to La Bomba (at the coast), cerro ca. 1 km NE of the caseta and on the W-side of the trail, 0˚ 14’ 10” S, 90˚ 44’ 41” W, 664 m alt., transition zone, on rock, 25-Mar-2006, Bungartz, F. 4857 (CDS 29053) ; just NW of the western peak, 0˚ 12’ 30” S, 90˚ 47’ 0” W, 880 m alt., humid zone 04-May-1971, Pike, L.H. s.n. (COLO 255653; L-55225); Pike, L.H. s.n. (COLO 255657; L-55229); Pike, L.H. 2760 (OSC 70785) ; summit of Cerro Gavilan , inner N- and NE-exposed crater rim, 0˚ 12’ 20” S, 90˚ 47’ 3” W, 840 m alt., humid zone, on rock, 23- Mar-2006, Aptroot, A. 65728 (CDS 32320) , Bungartz , F. 4797 (CDS 28929) . Isabela Island. Volcán Alcedo, eastern part of rim, Volcán Alcedo , humid zone, 09-Jul-1972, De Roy, T. s.n. (COLO 255977; L-55444); on the crater rim near the hut, 0˚ 26’ 33” S, 91˚ 5’ 31” W, 1100 m alt., humid zone, on bark, 07-Mar-2006, Aptroot, A. 65205 (CDS 31791) , 65258 (CDS 31844) , 65228 (CDS 31814) ; on top of the crater rim, 0˚ 27’ 33” S, 91˚ 6’ 49” W, 1051 m alt., humid zone, on rock, 05-Mar-2006, Bungartz, F. 4102 (CDS 28070) ; outer SE-exposed slope, ca. 100 m below the crater rim, 0˚ 25’ 36” S, 91˚ 5’ 12” W, 1146 m alt., humid zone, on rock, 06-Mar-2006, Bungartz, F. 4132 B (CDS 43293) , 4292 (CDS 28364) . Volcán Cerro Azul, between two lava ridges with deep holes (caved-in ceiling of lava tunnel); sheltered by steep rock ridges on both sides, 0˚ 55’ 6.5” S, 91˚ 24’ 29.6” W, 1624 m alt., high altitude dry zone, soil with mosses, 05-May-2012, Spielmann, A. 10516 (CDS 51871) , 10517 (CDS 51872) , 10404 (CDS 51759) ; wide, open ditch between two lava ridges to the West above Cerro Verde , 0˚ 57’ 9.40” S, 91˚ 24’ 31.5” W, 1436 m alt., humid zone, soil, 06-May-2012, Spielmann, A. 10563 (CDS 51932) . Volcán Darwin, ca. 1.5 km from the southwestern crater rim, 0˚ 12’ 20.5” S, 91˚ 18’ 52.79” W, 1280 m alt., high altitude dry zone, on soil, 14-Nov-2007, Bungartz, F. 7614 (CDS 38110) ; southwestern slope, above Tagus Cove , 0˚ 13’ 27.60” S, 91˚ 19’ 21.19” W, 860 m alt., transition zone, on rock, 15-Nov-2007, Ertz, D. 11928 (CDS 37287) , 11962 (CDS 37321) ; 0˚ 13’ 27” S, 91˚ 19’ 19.5” W, 874 m alt., transition zone, on soil, 15-Nov-2007, Bungartz, F. 7735 (CDS 38239) ; 0˚ 13’ 43.29” S, 91˚ 19’ 47.29” W, 724 m alt., transition zone, on soil, 12-Nov-2007, Ertz, D. 11779 (CDS 37138) . Volcán Sierra Negra, around the parking place at the end of the dirt road to the crater of Sierra Negra , 0˚ 49’ 45.10” S, 91˚ 5’ 17.10” W, 913 m alt., humid zone, 14-Aug-2008, Clerc, P. 08-157 (CDS 40011) ; close to the southern crater rim, along the trail to Alemania , 0˚ 51’ 12.69” S, 91˚ 8’ 40.5” W, 1055 m alt., humid zone, on soil, 16-Aug-2008, Bungartz, F. 8331 (CDS 40977) ; El Mango , on the E-side of the dirt road, 0˚ 53’ 1.7” S, 91˚ 0’ 50.79” W, 162 m alt., transition zone, on rock, 15-Aug-2008, Bungartz, F. 8203 (CDS 40849) , Bungartz , F. 8214 (CDS 40860) ; Truong , C. 1290 (CDS 39601) ; Clerc , P. 08-170 (CDS 40024) .

Lepraria vouauxii (Hue) R.C.Harris , in Egan (1987: 163). MycoBank no. 132223 ( Figs. 6a–b )

Thallus saxicolous; placodioid leprose, i.e., developing upon a common, shared hypothallus, prothallus fine, inconspicuous, main thallus distinctly delimited, but lacking a conspicuously ‘crisped’ lip (close, but not identical to the xerophila - type sensu Lendemer 2011a); surface deep yellow to brownish yellow, pale beige only along the margin and where the surface gets eroded; hypothallus inconspicuous, exposed only as a fine prothallus along the thallus margin or where granules on the surface have eroded; rhizohyphae absent or at least indistinct; granules pseudocorticate, very compact, coarse [(35–)40–70(–100) µm in diam., rather uniform in size], mature granules without conspicuous extruding hyphae, immature or damaged granules in eroded thallus parts rarely with few protruding hyphae; photobiont green, coccoid, 7–10 µm in diam.

Spot tests and chemistry: P+ reddish orange, K+ yellow orange, C−, KC−; UV−(dark); pannaric acid 6- methyl ester and accessories.

Distribution and ecology: Cosmopolitan ( Saag et al. 2009); previously reported from Ecuador by Flakus et al. (2013), but new to Galapagos; on vertical to overhanging, but ±exposed rock surfaces, though typically facing south or east and thus shaded, not receiving direct sunlight.

Notes: The species is easily recognized by its deep brownish beige to yellowish color and the distinctly delimited thalli of densely packed, compact granules with a distinctly pseudocorticate surface. Following the key to the Lepraria growth types in Lendemer (2011a) the species keys out within the finkii - type, although the specimens have a distinctly different appearance from all other Galapagos Lepraria species with this growth morphology. Despite lacking a ‘crisped’ lip, as is present in the closely related L. sipmaniana (Kümmerl. & Leuckert) Kukwa (2002: 226) , the granules of L. vouauxii are distinctly pseudocorticate and its thalli are well delimited, both characteristics not present in the finkii - type s.str. Based on these characters one might decide to regard its growth morphology as a distinctly separate type, but we prefer here to consider it to be a variation of the xerophila - type. Apparently the growth form of L. vouauxii can be quite variable. Lendemer (pers. comm.) reports that he has seen specimens of L. vouauxii growing close to the coast with a ±pseudocorticate appearance. He agrees that these specimens have more clearly delimited thalli that may better be accommodated in the xerophila - rather than the finkii - type.

The thalli of L. vouauxii often display a distinctive coloration pattern, with pale yellowish beige margins, deeper yellowish brown towards the center, and again pale yellowish beige or even whitish in the very center, where older parts have eroded.

Lepraria vouauxii not only looks quite different from the other species of Lepraria here assigned to the finkii - type, it is also chemically distinct. Due to the presence of dibenzofurans (in particular pannaric acid 6- methyl ester) it appears closely related to Lepraria tenella , a species that, like L. vouauxii and L. sipmaniana , has compact, pseudocorticate granules (see description of L. tenella ). However, the granules of L. tenella are pale yellowish to greenish white or ivory, not distinctly brown or beige, and soon branch into distinct pseudopodetia (see notes for that species).

Specimens examined. ECUADOR. GALAPAGOS: Santiago Island, summit of Cerro Gavilan, outer Sexposed crater rim, 0˚12’23” S, 90˚46’57” W, 840 m alt., on lava, 23-Mar-2006, Aptroot, A. 65476 A (CDS 32065) Aptroot, A. 65666 (CDS 32257) ; Bungartz, F. 4759 (CDS 28891) . Volcán Alcedo, Isabela Island, outer SE-exposed slope, ca. 100 m below the crater rim, 0˚25’36” S, 91˚5’12” W, 1146 m alt., on basalt outcrop, 06-Mar-2006, Bungartz, F. 4178 (CDS 28209) ; outer E-exposed slope just below the crater rim, 0˚25’17” S, 91˚5’8” W, 1077 m alt., on lava, 08-Mar-2006, Aptroot, A. 65171 (CDS 31755) .

Septotrapelia Aptroot & Chaves , in Aptroot et al. (2007: 127) MycoBank no. 29149 Synonym. Nelsenium Lendemer & Hodkinson (2013: 1013) MycoBank no. 564066

Septotrapelia usnica (Sipman) Kalb & Bungartz , comb. nov. MycoBank no. 804376 Basionym. Lepraria usnica Sipman (2003: 179) MycoBank no. 481766 Synonym. Nelsenium usnicum (Sipman) Lendemer & Hodkinson (2013: 1013) MycoBank no. 564067 Type:— EAST ASIA. SINGAPORE: Sembawan Park, on N-coast, 2 m, grassland with scattered trees and shrubs, on tree

trunk ( Cassia fistula , 80 cm in diam). within reach from the ground, 25 Nov 2000, Sipman, H.J.M. 46399 & Tan,

B.C. [B– Holotype (non vidi); SINU–isotype (non vidi)]. ( Figs. 4a–e )

Thallus saxicolous, terricolous, among bryophytes or plant debris, rarely corticolous, aggregating, i.e., initially of dispersed, scattered, isolated granules or small granule clusters, adhering to their substrate by scarce protruding hyphae forming an indistinct prothallus, secondarily aggregating to become contiguous (close to the alpina - type sensu Lendemer 2011a); surface yellowish green, color barely fading and ±persistent in the herbarium; hypothallus inconspicous, exposed only as a fine prothallus along the thalline granules; rhizohyphae absent or indistinct; granules initially small, ecorticate with sparse, short protruding hyphae [(40–)70–170(–200) µm in diam., very uneven in size], soon pseudocorticate, compact, becoming very coarse to almost subsquamulose [(220–)245–420(–580) µm in diam.]; then secondarily forming soredia. Apothecia very rare (not observed in the Galapagos specimens), initially pale, whitish, waxy, soon deep brown to blackened, but usually not strongly carbonized, initially rounded, with age becoming waved to irregular in outline, often closely grouped and becoming deformed, margin lecideine-biatorine, persistent, not excluded with age, disk plane, expanded, not becoming convex with age; proper exciple reddish brown throughout, most strongly pigmented along the outside, textura oblita; epihymenium deep reddish brown; subhymenium and hypothecium reddish brown; hymenium hyaline; paraphyses slender, barely branched, apically swollen, with a brown pigment cap; asci clavate, with a fuzzy IKI+ deep coat and a tholus with an IKI+ blue inner tube ( Byssoloma - type); ascospores 8 per ascus, but often only 2–3 maturing, hyaline, narrowly ellipsoid, often slightly bent, 3-septate, not constricted at the septa, (18.0–)20.7–27.6(–28.0) × (4.0–)4.6–6.2(–7.0) µm (n = 20). Pycnidia not observed. Photobiont green, coccoid, 7–10 µm in diam.

Spot tests and chemistry: P−, K± sordid yellow, KC−, C−; UV−; usnic acid, zeorin.

Distribution and ecology: Pantropical ( Saag et al. 2009); newly reported from the Galapagos; the most common truly leprose species in the Galapagos with a wide ecological amplitude, from the dry through the transition into the humid zone, on rock or soil, rarely on bark, typically in ±sheltered, semi-shaded to shaded cavities, vertical fronts, or below overhangs, rarely ±exposed, but typically not receiving direct sunlight.

Notes: Lendemer & Hodkinson (2013) recently published the new monotypic genus Nelsenium to accommodate “ Lepraria ” usnica . This genus was named in honor of Matthew P. Nelsen who previously demonstrated that this species belongs to the Pilocarpaceae ( Nelsen & Gargas 2008; Nelsen et al. 2008) unlike Lepraria s.str., which belongs in Stereocaulaceae .

The fertile material of “ Lepraria ” usnica from Ecuador examined here, clearly indicates, that this species is best placed in Septotrapelia , a genus recently described in Pilocarpaceae by Aptroot et al. (2006). Septotrapelia usnica has lecideine-biatorine apothecia with narrowly ellipsoid ascospores just like the type species of Septotrapelia , S. glauca (2007: 128) . The unique thallus morphology of “ Lepraria ” usnica also suggest that this species belongs to Septotrapelia . Although initially strictly leprose and composed of minute, compact granules (alpina - type sensu Lendemer 2011a), these granules eventually become quite large and have a microsquamulose appearance. Strictly speaking these bullate to microsquamulose granules are no longer truly leprose, because the granules often produce secondary soredia. These well developed granules are structurally extremely similar to thalli of S. glauca , although this species forms squamules that are much larger (up to 2000 µm wide) than the well developed granules of “ Lepraria ” usnica (max. 200 µm wide).

Because of this unique morphology, we are convinced that both the fertile specimens from continental Ecuador and the sterile thalli collected in Galapagos are conspecific with “ Lepraria ” usnica s.str. Even the sterile material is very distinct with its coarse granules that form secondary soredia and always contain usnic acid.

With the new combination proposed above, the genus Nelsenium Lendemer & Hodkinson (2013: 1013) becomes a synonym of Septotrapelia .

To clarify the species concept, it would be helpful to select an epitype from fertile specimens, but the holotype of “ Lepraria ” usnica was collected in East Asia ( Singapore) while the fertile material examined here originates from mainland Ecuador. As it is possible that fertile material from Singapore may eventually be found, it would be preferable to select the epitype from there .

Saag et al. (2009) characterize the distribution of “ Lepraria ” usnica as circum-tropical, ranging from Central and South America, Australia, southern and south-eastern Asia ( Singapore, Sri Lanka) to southern Africa. Ultimately molecular studies of specimens from all these regions will be needed to determine whether Septotrapelia usnica is indeed as widely distributed as the current species concept implies.

The material of “ Lepraria ” usnica used for the molecular studies was collected in Australia and Indonesia ( Nelsen & Gargas 2008; Nelsen et al. 2008). These sequences, which confirmed placement of this species in Pilocarpaceae , were subsequently used by Lendemer & Hodkinson (2003) to justify the new genus Nelsenium . Therefore, strictly speaking only the Australian and Indonesian specimens belong to Nelsenium s.str., a genus defined by Lendemer & Hodkinson (2003) based on an allele sequence different from that of Fellhanera bouteillei (Desm.) Vězda (1986: 214) .

Although future molecular studies may ultimately show that specimens from these geographically disjunct regions belong to several cryptic species within Septotrapelia , given, that the thalli of S. usnica are morphologically so distinct and chemically identical, it is highly unlikely that these specimens belong in different genera.

Aptroot et al. (2006) previously suspected that the sterile Galapagos material of this species belonged in Septotrapelia , but that this species was undescribed. During his visit to Galapagos, Aptroot identified the material he collected as two different species, suggesting that only specimens at CDS with the most minute granules were “ Lepraria ” usnica , and that specimens with larger granules belonged to “ Septotrapelia sp. nov.”. All the material is, however, chemically uniform, containing only usnic acid and zeorin. The size of the granules clearly varies considerably. Comparing all specimens with the fertile exsiccatae material it became evident, that the species is morphologically quite variable in granule size; thalli begin their growth from minute soredia, develop into larger, pseudocorticate granules that secondarily form soredia and when particularly well developed these granules even develop apothecia. The exsiccatae specimen is abundantly fertile, growing on soil and must have been collected in ideal growth conditions since the thalli are so well developed and fertile. No such material has been found in the Galapagos.

In the absence of fertile specimens it is not surprising that the species was described as a Lepraria ( Sipman 2003, 2004). Molecular studies previously demonstrated that it belongs to the Pilocarpaceae ( Nelsen & Gargas 2008; Nelsen et al. 2008), which is consistent with its transfer here to Septotrapelia .

A second species, morphologically very similar, but with granules of more homogenous size and more bluish green color, represented in CDS by two collections only, also appears to be present in Galapagos. It is chemically distinct containing oxodidymic acid and its accessories (for details about these secondary metabolites see Johansson et al. 2005), substances known from Letrouitia and Bapalmuia , another genus in the Pilocarpaceae (unpublished data by J. A. Elix). This species will not be described until more material is available.

Fertile material from continental Ecuador. ECUADOR. TUNGURAHUA: Southern slope of Mount Tungurahua north of Baños ; 1°28’S, 28° 26’W; 1800 m alt., on a humid, shaded earth bank [Südhang des Mt. Tungurahua N von Baños, an einem feuchten und schattigen Erdanriss], 16-Aug-1987, Kalb, K. & A. s.n. (Lichenes Neotropici, Fasc. XV; to be distributed) .

Additional, sterile specimens examined from Galapagos. ECUADOR. GALAPAGOS: Floreana Island, at the base of Cerro Comunista , 1˚17’22.89” S, 90˚28’22.39” W, 158 m alt., on small basalt rock, 16-Jan-2011, Bungartz, F. 9689 (CDS 47006) ; lower S-slope of Cerro Ventanas , 1˚16’36.10” S, 90˚25’41.10” W, 295 m alt., on small basalt rock, 18-Jan-2011, Bungartz, F. 9862 (CDS 47200) . San Cristóbal Island, Cerro Colorado summit, around the viewpoint, 0˚54’54.89” S, 89˚26’1.5” W, 159 m alt., dry zone, on basalt rocks, slope 15° SWW, 24-Aug-2008, Clerc, P. 08-274 (CDS 40128) ; Cerro Colorado , enclosure for Calandrinia galapagosa near the viewpoint on the top, 0˚54’58” S, 89˚26’5” W, 130 m alt., on weathered tuff outcrop 29-Apr-2007, Bungartz, F. 6739 (CDS 34983) ; Bungartz , F. 6741 (CDS 34985) . Santa Cruz Island, along the road from Bellavista to Los Gemelos, 0˚38’12” S, 90˚23’46” W, 574 m alt., on lava, 12-Feb-2006, Aptroot, A. 63926 (CDS 30482) ; along the road from Bellavista to Los Gemelos, 0˚38’12” S, 90˚23’46” W, 574 m alt., on vertical soil bank, 12-Feb-2006, Bungartz, F. 3463 (CDS 27178) ; Bungartz , F. 3467 (CDS 27222) ; 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., growing over Frullania sp. , 21-Jan-2010, Jonitz, H. 32 (CDS 44653) ; near Los Gemelos craters, 0˚36’31” S, 90˚22’4” W, 350 m alt., on lava, 31-May-2005, Aptroot, A. 63376 (CDS 30122) ; Aptroot , A. 63373 (CDS 30119) ; Aptroot , A. 63369 (CDS 30115) ; near Puntudo , 0˚38’41” S, 90˚20’13” W, 750 m alt., 27-May-2005, Aptroot, A. 63165 (CDS 29896) ; Puerto Ayora , cliff N of the town, 0˚43’59” S, 90˚18’45” W, 20 m alt., on lava, 11-Feb-2006, Aptroot, A. 63731 (CDS 30288) ; Puerto Ayora , near start of road to Baltra, 0˚44’34” S, 90˚18’45” W, 25 m alt., on lava, 26-May-2005, Aptroot, A. 63096 (CDS 29826) ; tras del Puntudo , ex finca de Don Benito, 0˚38’27.10” S, 90˚19’59.39” W, 732 m alt., on Cinchona pubescens , 07-Jul-2006, Nugra, F. 31 (CDS 32684) . Santiago Island, 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. on basalt outcrop, 22-Mar-2006, Bungartz, F. 4681 (CDS 28768) ; along the trail from Cerro Gavilan to La Central, 0˚13’2” S, 90˚46’33” W, 890 m alt., on on open soil, 24-Mar-2006, Bungartz, F. 4832 (CDS 29006) ; 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., on small rock, 18-Jul-2006, Bungartz, F. 5218 (CDS 29431) ; small hill ca. 1 km inland from the E-coast, at the same latitude as Isla Bartolomé , 0˚17’40” S, 90˚35’10” W, 77 m alt., on N-exposed overhang, 20-Jul-2006, Bungartz, F. 5257 (CDS 29473) ; Bungartz , F. 5291 (CDS 29507) ; Bungartz , F. 5292 (CDS 29508) ; summit of Cerro Gavilan , inner N- and NE-exposed crater rim, 0˚12’20” S, 90˚47’3” W, 840 m alt., on lava, 23-Mar-2006, Aptroot, A. 65643 (CDS 32233) ; trail from Cerro Gavilan to summit of Jaboncillos, 0˚12’30” S, 90˚46’59” W, 850 m alt., 23-Mar-2006, Aptroot, A. 65502 (CDS 32091) . Isabela Island, Volcán Alcedo, cerca las fumarolas, 0˚26’22.10” S, 91˚8’35.39” W, 900 m alt., sobre ramas, 1-Dec-2006, Nugra, F. 162 (CDS 32816) ; on inner crater rim above the fumaroles, 0˚27’29” S, 91˚7’19” W, 1089 m alt.,, on top of basalt boulder, 5-Mar-2006, Bungartz, F. 4060 (CDS 27990) ; on top of the crater rim, 0˚27’33” S, 91˚6’49” W, 1051 m alt., on basalt boulder, 5-Mar-2006, Bungartz, F. 4095 (CDS 28063) ; outer SE-exposed slope, ca. 2 km below the crater rim, 0˚26’16” S, 91˚4’36” W, 798 m alt., on small rock on the ground, 07-Mar-2006, Bungartz, F. 4200 (CDS 28242) ; Bungartz , F. 4180 (CDS 28222) ; upper NNW-exposed slope inside the crater, 0˚27’27” S, 91˚7’23” W, 1055 m alt., on top of boulder, 05-Mar-2006, Bungartz, F. 4094 (CDS 28058) ; along the crest of a lava ridge emerging from the ash fields, 0˚56’6.5” S, 91˚24’30.30” W, 1622 m alt., over moss on basalt cliff, 05-May-2012, Bungartz, F. 10370 (CDS 52340) . Volcán Darwin, ca. 1.5 km from the southwestern crater rim, 0˚12’20.5” S, 91˚18’52.79” W, 1280 m alt., on overhang, 14-Nov-2007, Ertz, D. 11871 (CDS 37230) ; southwestern foothills, above Tagus Cove (1st campsite), 0˚14’50” S, 91˚21’29.89” W, 67 m alt., on overhang of basalt rock, 11-Nov-2007, Ertz, D. 11751 (CDS 37110) ; southwestern slope, above Tagus Cove , 0˚13’28.19” S, 91˚19’17.89” W, 872 m alt., on lava, 15-Nov-2007, Bungartz, F. 7747 (CDS 38253) ; southwestern slope, above Tagus Cove (2nd campsite), 0˚13’43.29” S, 91˚19’47.29” W, 724 m alt., on lava, 12-Nov-2007, Bungartz, F. 7435 (CDS 37922) ; Bungartz , F. 7424 (CDS 37911) ; close to Volcán Chico , along the trail, 0˚46’57.79” S, 91˚5’59.39” W, 944 m alt., on basaltic rocks, 14-Aug-2008, Clerc, P. 08-146 (CDS 40000) ; Truong , C. 1268 (CDS 39579) ; La Cueva Sucre, abandoned farm bought by the National Park , 0˚50’34.60” S, 91˚1’39.10” W, 362 m alt., agricultural area, on the ground, 15-Aug-2008, Bungartz, F. 8253 (CDS 40899) ; Muro de las Lagrimas, ca. 5 km W of Puerto Villamil, 0˚57’52.70” S, 91˚0’46.79” W, 78 m alt., on overhang, 17-Aug-2008, Bungartz, F. 8443 (CDS 41089) ; Bungartz , F. 8444 (CDS 41090) ; top of the northern crater rim, 0˚48’3” S, 91˚5’25.89” W, 968 m alt., on small basalt rock, 08-Sep-2007, Bungartz, F. 6780 (CDS 36199) .

Key to leprose and leproid lichens of the Galapagos

1. Thallus, at least in parts, brightly colored; vivid neon-yellow or neon-green .............................................................. 2

- Thallus dull; greenish grey, dark green, bluish green or bluish grey, pale green, ivory white, pale yellow, never vivid neon-yellow or neon-green .......................................................................................................................................... 5

2. Thallus bright neon-yellow (pulvinic acid, pulvinic dilacetone, pinastric acid, and/or vulpinic acid); coarse to fine granules (typically> 15 µm in diam.)........................................................................................................................... 3

- Thallus bright neon-green (rhizocarpic acid); very fine, farinose granules (10–15 µm in diam.); apothecia, if present, biatorine-lecidine, not stalked (not observed in the Galapagos specimens); photobiont trebouxioid ( Fig. 1c ) ............. .......................................................................................................... Psilolechia lucida (Ach.) M. Choisy (1949: 142)

3. Thallus mostly pale green, rarely in parts with a bright neon green pruina (vulpinic acid), pruina typically restricted to the stalked, mazaediate apothecia, rarely traces of the pruina also present in the thallus; photobiont trebouxioid ( Fig. 1a–b ) ............................................................................................. Chaenotheca chloroxantha Tibell (2008: 727)

- Thallus bright neon-yellow ........................................................................................................................................... 4

4. Thallus a fine farinose dust of minute, evenly sized soredia [(15–)20–30(–40) µm in diam.]; with pinastric acid ( Fig. 1d ) ....................................................................................................... Chrysothrix xanthina (Vain.) Kalb (2001: 144)

- Thallus of coarse, compact, pseudocorticate granules (240–280 µm in diam.) that sometimes aggregate into a thallus with almost bullate-areolate appearance (pseudoareolate), secondarily developing smaller-sized, soredia-like granules [(20–)40–60(–80) µm in diam.]; lacking pinastric acid ( Figs. 1e–f ) ...................................................................... ................................................................................. 1 Chrysothrix galapagoana K. Knudsen & Bungartz (2013: 175) 1 In Bungartz et al. (2013a) this Galapagos material was previously reported as C. aff. occidentalis Elix & Kantvilas (2007: 361) , a species that also has pseudoareolate granules. Granules of C. galapagoana are, however, generally much larger (often over 500 µm), ecorticate and do not secondarily form smaller-sized soredia-like granules. Unlike C. occidentalis , which is typically fertile, no fertile matrial of C. galapagoana has so far been found. At first glance superficially similar is C. insulizans R.C. Harris & Ladd (2008: 35) , but this species does not develop pseudoareolate thalli, instead its “islands” are secondarily aggregating granules.

5. Thallus finely granular to microsquamulose; lacking secondary metabolites; all spot tests negative (P, K −, KC −, C −), no UV fluorescence (UV −) ..................................................................................................sterile thalli of Bacidia s.l.

- Thallus with secondary metabolites (sometimes only detected by TLC); typically with at least some positive spot test reactions and/or distinct UV fluorescence ............................................................................................................. 6

6. Thallus when well developed with stalked, mazaediate apothecia covered by scant bright neon-yellow pruina (vulpinic acid); pruina restricted only to the apothecia and stalk, typically absent from the thallus granules; thallus with unknown pulvinic acid derivates (R f 62, 63, 65, UV+ bright greenish yellow after charring with H 2 SO 4), rarely also with traces of vulpinic acid ( Fig. 1a–b ) .............................................................................. Chaenotheca chloroxantha

- Thallus lacking apothecia, pulvinic acid derivates absent .......................................................................................... 7

7. Thallus granules soon budding into branched gnarled, pseudocorticate pseudopodetia ( Fig. 6c–d ) ............................ .............................................................................................................................................................. Lepraria tenella

- Thallus granules occasionally budding, but not forming distinct pseudopodetia ....................................................... 8

8. The main thallus of leproid appearance, i.e., not composed entirely of granules, but with a compact, cottony-ecorticate to smooth-corticate surface from which abundant soredia or pseudoisidia are formed, which often obscure the structure of the thallus below; an arachnoid prothallus may be present or absent along the margin .......................... 9

- The main thallus truly leprose, i.e., granules forming the main thallus itself, either scattered and developing among prothalline hyphae or developing upon a loose to dense, arachnoid to byssoid hyphal matt (hypothallus); an arachnoid prothallus is always present along the margin ................................................................................................... 17

9. Thallus conspicuous, well developed, surface cottony, ecorticate ........................................................................... 10

- Thallus often ±immersed in the substrate and poorly developed, where visible forming a smooth, corticate surface. .................................................................................................................................................................................... 12

10. Thallus with sparse to abundant granular soredia, typically also in part with pustulate ascigerous areas; medulla at least in parts I Lugol’s + blue .................................................................................................................. Cryptothecia spp.

- Thallus with sparse to abundant pseudisidia (i.e., ecorticate isidia), medulla I − throughout .................................... 11

11. Thallus P+ red, with protocetraric acid; prothallus deep brown, rarely with distinct ascomata that contain fusiform, septate ascospores ( Figs. 3b–d ) ............................................................. Syncesia leprobola Nyl. ex Tehler (1996: 37)

- Thallus P or P+ golden yellow, protocetraric acid absent, but often with other substances; prothallus white, rust red or carmine red, not brown; ascospores muriform, not formed in distinct ascomata 2 ........................ Herpothallon spp. 2 Ascospores have so far only been reported from one species ( H. fertile ) in the genus; not known from Galapagos (Bungartz et al. 2013).

12. Thallus C −, UV −, lacking xanthones ........................................................................................................................ 13 - Thallus C+ orange, UV+ deep orange, with xanthones.............................................................................................. 15

13. Thallus with atranorin, K+ yellow, P+ yellow; pale greenish white to yellowish white; growth aspect dominated by coarsely granular, compact, smooth, pseudocorticate soredia .................................................................................. 14

- Thallus with usnic acid, K± sordid yellow, P −; pale yellowish green to pale yellow; growth aspect dominated by fine to coarse, cottony ecorticate soredia ( Fig. 2e ) ........................................................................................ 3 Lecanora sp. 3 The specimens contain a conspicuous array of unidentified terpenoids (in old herbarium material often forming needle-shaped crystals extruding from the granules, giving the thallus a moldy appearance); the same series of terpenoids occur also in Lecanora dissoluta, Nyl. (1866: 131) but that species contains atranorin rather than usnic acid. Morphologically the specimens are close to L. perconfusa Printzen (2001: 400) , though clearly leproid, i.e., very abundantly sorediate. The Galapagos material is exclusively saxicolous, whereas L. perconfusa s.str. is more commonly encountered on bark and wood. Galapagos Lecanora species will be treated in detail in a separate publication.

14. Apothecia, if present, lecanorine, with a deep orange margin and a dark, brown orange disk ( Figs. 2a–b ) ................. ... sorediate thalli of Brigantiaea leucoxantha (Spreng.) R. Sant. & Hafellner , in Hafellner & Bellemère (1982: 246) - Apothecia, if present, biatorine-lecideine, initially unpigmented (“paraffineous”), soon tainted by a bluish black pigment ( Fig. 2c ) ................................................................................. 4 Catillochroma pulverea (Borr.) Kalb (2007: 303) 4 Sterile thalli of the two species can typically not reliably be distinguished. Both Catillochroma and Brigantiaea contain atranorin and zeorin. Fumarprotocetraric acid has been reported from C. pulverea , but this secondary metabolite is not present in the Galapagos material. The exciple of the specimens contains an abundance of characteristic, minute crystals that do not dissolve in K, N or C. These crystals are evenly dispersed throughout the distinct outer layer of a prosoplectenchymatous exciple of thin walled, mostly unpigmented, parallel hyphae. This outer layer is clearly separated from an inner exciple part of interwoven hyphae [without entering into the recent discussion about the distinction of Catillochroma from Megalaria ( Fryday & Lendemer 2010) , we here follow Kalb 2007].

Sorediate thalli of Brigantiaea are very common in the humid highlands of Galapagos and typically found at least with few, scattered apothecia; fresh thalli have a more yellowish green appearance than those of Catillochroma ; very rarely traces of anthraquinones can be found in the thalli of Brigantiaea , possibly from areas where apothecia later emerge.

15. Thalli with very minute, granular soredia [mostly less than 50(–75) µm in diam.] with a distinct brownish beige tinge; apothecia 5, if present, deep reddish brown to almost blackened, lecideine, disk soon strongly convex and the proper exciple soon excluded ( Fig. 2d ) ........................................... Pyrrhospora quernea (Dicks.) Körb. (1855: 209) 5 Apothecia not known from Galapagos specimens, but specimen morphology identical to fertile material of Vězda Lich. Sel. Exs. no. 549 (COLO 216762, L-45665).

- Thalli with small, granular, pale yellowish green soredia [typically larger than 35 µm in diam.], not brownish or beige; apothecia, if present, pale greenish, in parts blackening (bluish black, but never reddish), lecanorine, thalline exciple often poorly developed, but typically visible at least in parts, disk flattened to barely convex ................... 16

16. Thalli with 3- O -methylthiophanic acid and thuringione, always containing atranorin ( Fig. 2f ) ................................... ................................................................................................................ Vainionora aemulans (Vain.) Kalb (1991: 3)

- Thalli with thiophanic acid, rarely containing atranorin .......................................................... 6leproid Vainionora sp. 6 Galapagos specimens of this possibly undescribed taxon were previously identified as Lecanora expallens Ach. (1810: 374) , but consistently lack usnic acid and have a chemistry very similar to Pyrrhospora quernea . However, the specimens lack the brownish tinge characteristic for most specimens of Pyrrhospora and some of the Galapagos specimen are fertile with lecanorine apothecia. Chemistry. P −, K −, KC± pale orange, C+ orange; UV+ deep orange; ca. 50% of the specimens contain atranorin, thiophanic acid, arthothelin, 2,4-dichloronorlichexanthone and/or 4,5- dichloronorlichexanthone, a slow moving unknown xanthone at R f 4, an unknown spot at R f 13 (UV+ pale blue before charring). The species will be treated in an separate publication.

17. Hypothallus a loose arachnoid weft of hyphae, in part aggregating into distinct fibrous hyphal strands upon which large, ‘fluffy’, ecorticate granules develop [= granulose pseudisidia, very uneven in size, (28–)40–100(–200) µm in diam.]; thallus containing perlatolic acid ( Fig. 3a ) [ Herpothallon ] .......................................................................... 18

- Hypothallus not aggregating into fibrous strands; thallus granules smaller and ±of the same size [mostly 30–60(– 100) µm in diam.], if larger granules present (> 100 µm in diam.), then these distinctly pseudocorticate; thallus lacking perlatolic acid ....................................................................................................................................................... 19

18. Thallus K–, P– (perlatolic acid); on bark............... Herpothallon granulare (Sipman) Aptroot & Lücking (2009: 43) - Thallus K+ yellow, P+ yellow (brialmontin 1 & 2, confuentic acid); on rock ..............................................................

..................................................................................................... Herpothallon saxorum Bungartz & Elix (2013: 19)

19. Thallus initially composed of dispersed, isolated granules, secondarily forming larger thalli (aggregate leprose thalli sensu Lendemer 2011a) ............................................................................................................................................. 20

- Thallus granules embedded in and developing from a shared hypothallus, eventually expanding into larger thalli from which clusters of granules may secondarily be dispersed (placodioid leprose thalli sensu Lendemer 2011a) ..... ................................................................................................................................................................................... 21

20. Thallus yellowish green, usnic acid present, P−, K± sordid yellow; granules very irregular in size; initially scattered, small, immature granules with protruding hyphae, soon becoming larger, pseudocorticate and, with age, secondarily budding off soredia; apothecia blackish brown, lecideine-biatorine, not known from Galapagos ( Figs. 4a–e ) ............ ...................................................................................................................................................... Septotrapelia usnica

- Thallus bluish green to lead grey, with oxodidymic acid and accessories, P+ yellow, K+ yellow; granules minute, uniform in size [(35–)40–60(–70) µm in diam.], compact, pseudocorticate ( Fig. 4f ) ................... 7 Septotrapelia sp. 1 7 Only two Galapagos specimens of this leprose taxon containing 4,5-dichlorolichexanthone, oxodidymic, dioxocondidymic, dioxodidymic, and dioxosubdidymic acid have so far been collected. Oxodidymic acid and accessories have also been observed in the genus Bapalmuia , which, like Septotrapelia is also a member of the Pilocarpaceae .

21. Thallus beige to cream colored (in the herbarium ±yellowish beige), individual granules compact, pseudocorticate, with short extruding hyphae only where the thallus is damaged or in young, immature granules; thallus margin distinctly delimited, but lacking a well defined ‘cripsed’lip (similar to the xerophila - type sensu Lendemer 2011a); with pannaric acid 6-methylester .............................................................................................................. Lepraria vouauxii

- Thallus pale green to bluish green (in the herbarium ±pale whitish to ivory), individual granules loose, ‘fluffy’, always completely ecorticate, often with long, conspicuous extruding hyphae; thallus margin irregular to inconspicuously lobed, never ‘crisped’( finkii - type s.str. sensu Lendemer 2011a); always lacking pannaric acid 6-methylester. .................................................................................................................................................................................... 22

22. Thallus C+ bright red, with lecanoric acid; hypothallus thin, arachnoid; granules powdery ........ Lepraria achariana - Thallus C −; hypothallus thick, cottony; granules powdery or mealy ........................................................................ 23

23. Thallus with stictic acid; P+ orange, K+ yellow; granules mealy .......................................................... Lepraria finkii - Thallus lacking stictic acid; P −, K −; granules powdery or mealy ............................................................................. 24

24. Thallus with divaricatic acid, UV+ pale whitish yellow; granules mealy ..................................... Lepraria aff. incana - Thallus with methyl barbatate and 4,5-dichlorolichexanthone, UV± dull orange yellow (ochraceous); granules pow-

dery ................................................................................................................................................ Lepraria lendemeri

Figures

FIGURE 1. af Galapagos leprose and leproid lichens with brightly colored pigments; a–b Chaenotheca chloroxantha; a Overview of the granular leproid thallus; photograph of fresh material in the field, whitish to pale yellow pruina covering apothecial stalks intensifying with storage in the herbarium (Bungartz 8509; scale 1.5 mm); b Close-up of the thallus; stalked (‘calicioid’) apothecia with bright yellow pruina (vulpinic acid) confined to the stalks (Clerc 08-361; scale 1 mm); c powdery, dusty leprose thallus of Psilolechia lucida; close-up of bright neon green thallus grains (Aptroot 65143; scale 0.4 mm); d powdery, dusty leprose thallus of Chrysothrix xanthina; close-up of bright lemon yellow thallus grains (Bungartz 8832; scale 0.6 mm); e–f Chrysothrix galapagoana (scale bars 1 mm); e General thallus aspect of coarse almost subsquamulose leproid granules (Bungartz 9756; scale 2 mm); f Close-up of subsquamulose leproid granules with budding soredia (Bungartz 5256; scale 1 mm).

FIGURE 2. Galapagos leprose and leproid lichen species that occasionally bear apothecia; a–b Abundantly sorediate thalli of Brigantiaea leucoxantha s.l.; a Overview of the granular sorediate (leproid) thallus with rusty orange, lecanorine apothecia with olive orange, yellowish pruinose disk; photograph of fresh, humid material in the field (Bungartz 5602; scale 2 mm); b Close-up of the heavily granular sorediate thallus with few bright orange apothecia; herbarium material (Bungartz 3473; scale 2 mm); c Overview of the granular sorediate (leproid) thallus of Catillochroma pulverea with deep brownish to blackened apothecia (Bungartz 3964; scale 2 mm); d Overview of the brownish beige granular sorediate (leproid) thallus of Pyrrhospora quernea with deep reddish brown biatorine-lecideine apothecia; fertile material collected in California (Bungartz 8078; scale 4 mm); Galapagos material (not pictured) has so far only been found sterile; e Leproid thallus of Lecanora sp.; the fuzzy appearance of the granulose soredia caused by terpenoid crystals forming in the herbarium; the main thallus almost entirely dissolved; fertile material not known from Galapagos (Aptroot 65410; scale 0.5 mm); f Leproid thallus of Vainionora aemulans formed almost entirely by granular soredia; the main thallus almost entirely dissolved; fertile material not known from Galapagos (Aptroot 65060; scale 0.8 mm).

FIGURE 3. Galapagos lichen thalli with pseudisidia; a Leprose thallus of Herpothallon granulare with granular ‘pseudisidia’ developing on fibrous hypothallus strands (Nugra 889; scale 5 mm); b–d Syncesia leprobola; b Thallus densely covered in pinkish pseudisidia (ecorticate, isidioid outgrowths); the thallus along the margin often aggregating into ‘rhizomorphic’ thallus strands (which are not exclusive to Syncesia rhizomorpha!), and clearly delimited by a deep brown arachnoid hypothallus (Bungartz 5021; scale 2.5 mm); c Densely pseudisidiate thallus; the only areas not covered in pseudisidia are regions where immature pseudothecia begin to develop (Bungartz 4810; scale 2 mm); d Densely pseudisidiate thallus with mature pseudothecia (Bungartz 8213; scale 1 mm).

FIGURE 4. Galapagos species of Septotrapelia; a–e S. usnica; a Leprose thallus composed of dispersed granules with some tendency to aggregate, larger granules secondarily budding off soredia (Bungartz 8443; scale 1 mm). b Fertile thallus of pseudocorticate, aggregated granules with ±tendency to become subsquamulose; apothecial initial (arrow), mature apothecia (a) and large aggregated apothecia (ag) (Kalb s.n., Lichenes Neotropici, Fasc. XV; scale 2 mm); c–e Section of an apothecium (Kalb s.n., Lichenes Neotropici, Fasc. XV); c Overview of the apothecium with exciple, hymenium and hypothecium (scale 100 µm); d Exciple and hymenium with ascus (arrow; scale 50 µm); e 3-septate ascospores (scale 25 µm); f Septotrapelia sp. 1; granules growing on plant debris (Bungartz 8183, scale 1.5 mm).

FIGURE 6. Galapagos Lepraria species with pannaric acid 6-methylester. a–b Lepraria vouauxii; a Insular thalli delimited by a blackened, necrotic zone where merging surrounding ±damaged, grayish thalli of Lepraria finkii (Aptroot 65476 A—L. vouauxii, Aptroot 65476 B—Lepraria finkii; scale 3 mm); b Close-up of the thallus of compact thalline granules with a brownish beige pseudocortex, and damaged parts exposing a whitish ‘medulla” inside; closely packed together, but not forming the characteristic crisped lip otherwise typical of the xerophila-type (Aptroot 65666; scale 1 mm); c–d Lepraria tenella; c Overall growth aspect (Bungartz 8214; scale 3 mm). d Close up of the pseudopodetia with pseudocorticate granules (Bungartz 4857; scale 1 mm).