Lecanora terpenoidea Bungartz & Elix, 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 : 71

Lecanora terpenoidea Bungartz & Elix sp. nov. MycoBank no. 833379

Diagnosis. Characterized by a leproid thallus similar to Lecanora orosthea (Ach.) Ach. and L. perconfusa Printzen , but differs in lacking xanthones and in containing a conspicuous series of terpenes (the same terpenes as in Lecanora dissoluta Nyl. ) in addition to usnic acid and zeorin.

Type:— ECUADOR. GALÁPAGOS: Santiago, along the trail from Bucanero to Jaboncillos, ca. 3 km SE of Bucanero, 0˚10’52’’ S, 90˚48’33’’W, 362 m alt., transition zone, open woodland of large Bursera graveolens and smaller Psidium galapageium trees, grassland and basalt boulders in between, on lava, 22-Mar-2006, Aptroot, A. 65410 ( CDS 31996– holotype).

( Fig. 18F )

Thallus saxicolous, leproid, primary thallus indistinct, almost entirely dissolved into ecorticate, granular soredia on a byssoid arachnoid (‘fluffy’, ‘cottony’) hypothallus, effuse, not distinctly delimited, granules yellowish green, somewhat paler where eroded, ecorticate, ill-defined, mealy, very variable in size, rarely extremely finely farinose (4.5–)9.5–22(–42) µm in diam. especially where eroded, but usually larger, (82–)91–133(–142) µm in diam., occasionally irregularly aggregating, generally loosely packed, becoming covered by a coating of needle-shaped crystals after prolonged storage in the herbarium; photobiont green, coccoid, 6–12 µm in diam. Apothecia and pycnidia unknown.

Chemistry: Thallus cortex P−, C−, KC± yellowish brown, K± yellowish brown, UV−(dull); with usnic acid [major], zeorin [minor], and an extensive array of unidentified terpenes [minor] (the same, characteristic terpenes occur in Lecanora dissoluta and form a coating of needle-shaped crystals in old herbarium specimens, giving the thallus an overall moldy appearance) [specimens analyzed with TLC: Aptroot, A. 65410 ( CDS 31996 – holotype), 65401 ( CDS 31987 ), 65588 ( CDS 32177 ); Bungartz, F. 4860 ( CDS 29056 )] .

Etymology: Named for its characteristic series of terpenes.

Ecology and Distribution: Known only from the Galapagos; all specimens occur on ±sheltered and shaded rocks in the transition zone.

Notes: This species, formally described here, has previously been reported as Lecanora sp. by Bungartz et al. (2013) in their key to the leprose and leproid Galapagos lichens. Lecanora dissoluta contains the same set of terpenoids, but produces atranorin instead of usnic acid and an unknown pigment ( Elix & Lumbsch 1996).

Additional specimens examined (paratypes). ECUADOR. GALÁPAGOS: Santiago, along the trail from Bucanero to Jaboncillos, ca. 3 km SE of Bucanero, 0˚10’52’’ S, 90˚48’33’’W, 362 m alt., transition zone, open woodland of large Bursera graveolens and smaller Psidium galapageium trees, grassland and basalt boulders in between, lava, on rock, 22-Mar-2006, Aptroot, A. 65410 ( CDS 31996); along the trail from Bucanero to Jaboncillos, ca. 3 km SE of Bucanero, 0˚10’52’’ S, 90˚48’33’’W, 362 m alt., transition zone, open woodland of large Bursera graveolens and smaller Psidium galapageium trees, grassland and basalt boulders in between, lava, on rock, 22-Mar-2006, Aptroot, A. 65401 ( CDS 31987); 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, vertical, SE-exposed cliff face with ferns ( Blechnum polypodioides and Pityrogramma calomelanos var. calomelanos ) growing in crevices, on rock, 25-Mar- 2006, Bungartz, F. 4860 ( CDS 29056); Guayabillos nuevo abierto, 0˚14’0’’ S, 90˚43’52’’W, 625 m alt., transition zone, open woodland of Psidium galapageium , Zanthoxylum fagara , Bursera graveolens , Trema micrantha and shrubs of Clerodendrum molle in between, on rock, 25-Mar-2006, Aptroot, A. 65588 ( CDS 32177).

Figures

FIGURE 18. Species in the L. varia-group.A–E. Lecanora strobilina. A–B. Thallus variation.A. thick rimose-areolate,pale yellow thallus with adnate apothecia, farinose soredia developing irregularly from the thallus surface and along the apothecial margin, discs epruinose, golden yellow (Nugra, F. 124, CDS 32778). B. scant rimose thallus on a black hypothallus, farinose soredia forming irregular from the surface and apothecial margin, discs epruinose, golden yellow (Bungartz, F. 7859, CDS 38368). C–E. Apothecial section (Nugra, F. 124, CDS 32778). C. Exciple abundantly filled with minute crystals and yellowish brown pigment, pigment and crystals extending across epihymenium, hypothecium hyaline (in water, DIC). D. After treatment with 10% KOH, crystals and pigments dissolved, trebouxioid photobionts more easily distinguished (in KOH, DIC). E. Characteristically small, narrowly oblong ascospores (in KOH, DIC). F. Leproid thallus of Lecanora terpenoidea, sorediate granules embedded among cottony thallus hyphae, with prolonged herbarium storage forming abundant terpenoid crystals that give the thallus a conspicuous ‘fluffy’ appearance (Aptroot, A. 65410, CDS 31996–holotype). Scales: A, B & F= 5 mm; C & D =100 µm; E = 10µm.