Vainionora aemulans (Vain.) Kalb (1991: 3) 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 : 73-75

Vainionora aemulans (Vain.) Kalb (1991: 3) MycoBank no. 362888

Type:— BRASIL. MINAS GERAËS: Carassa , 1885, Vainio, E.A. s.n. [= Lich. Bras. Exs. 1380] (Tur-V 5612– lectotype selected by Kalb, in herb.) .

( Fig. 20A–B )

Thallus corticolous or lignicolous (possibly also saxicolous, see comments below), leproid, almost entirely composed of coarse, granular soredia which develop on the surface of a thin ±contiguous, whitish, membranaceous prothallus over a discolored, ±blackened substrate; granules pseudocorticate, yellowish green to pale greenish beige, somewhat paler where eroded, coarse [±equal in size, (43–)57–71(–114) µm in diam., irregularly aggregating], usually forming a moderately thickened, granular verrucose crust or, if particularly well developed, granules becoming branched, coralloid and forming a thick, secondary, rimose-areolate crust. Apothecia and pycnidia not seen in the Galapagos specimens.

Chemistry: Thallus cortex P+ yellow, K+ yellow, KC+ orange, C+ orange, UV+ deep to bright orange; with atranorin [major], thuringione [major], arthothelin [minor], 3- O -methylthiophanic acid [minor]; [specimens analyzed with TLC: Bungartz, F. 4017 ( CDS 27947); Aptroot, A. 65707 ( CDS 32299), 65170 ( CDS 31754)].

Ecology and Distribution: Pantropical; first reported from the Galapagos by Bungartz et al. (2013); occurring in the humid and transition zones, on the bark of native trees and shrubs ( Zanthoxylum , Tournefortia ), in ±shaded to sheltered as well as sunny, exposed habitats; possibly also on rock (see comments below).

Notes: All the Galapagos specimens examined lack apothecia but are chemically identical to V. aemulans . However, only the corticolous collections could be identified with certainty. The two saxicolous specimens were previously tentatively identified as L. expallens Ach. ( Bungartz et al. 2011) . These specimens have more exuberant thalli composed of ±coralloid granules, more similar to a Leprocaulon than to typical V. aemulans .

Specimens of V. aemulans s.str.; on bark. ECUADOR. GALÁPAGOS: Isabela, Volcán Alcedo, outer SE-exposed slope and crater rim, 0˚27’29” S, 91˚7’19”W, 1089 m alt., humid zone, tortoise pasture with scattered trees ( Tournefortia rufo -sericea, Zanthoxylum fagara ), on bark of Zanthoxylum , 5-Mar-2006, Aptroot, A. 65060 ( CDS 31642); Bungartz, F. 4017 ( CDS 27947).

Specimens of V. aemulans s.l.; on rock. ECUADOR. GALÁPAGOS: Santiago, 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 , Doryopteris palmata , Adiantum concinnum , Blechnum polypodioides ) growing in crevices, on lava rock, 23-Mar-2006, Aptroot, A. 65707 ( CDS 32299). Isabela, Volcán Alcedo, outer E-exposed slope just below the crater rim, 0˚25’17” S, 91˚5’8”W, 1077 m alt., humid zone, basalt outcrops, SE-exposed slope with scattered shrubs of Tournefortia rufo -sericea, Opuntia insularis , Lantana peduncularis and occasional trees of Zanthoxylum fagara among basalt rubble, on lava rock, 8-Mar- 2006, Aptroot, A. 65170 ( CDS 31754).

Figures

FIGURE 20. Species of Vainionora. A–B. Thallus variation of Vainionora aemulans. A. Granular-leproid thallus growing on smooth bark of Zanthoxylon (Aptroot, A. 65060, CDS 31642). B. Granular-leproid thallus growing on coarse basalt lava (Aptroot, A. 65170, CDS 31754). C–D. Vainionora nugrae (Nugra, F. 279, CDS 33195–holotype). C. Thallus coarsely granular, pale yellowish green, with crenate lecanorine apothecia with blackened disc covered in a fine yellowish green pruina. D. Apothecial section (in water, DIC): exciple with large crystals only; epihymenium yellowish brown, lacking crystals; subhymenium well developed, distinctly yellowish brown. Scales: A, B & C = 5 mm; D =100 µm.