Lecanora varia

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 : 62

Lecanora varia -group ( Figs. 15–17 )

A polyphyletic assemblage of taxa that have granular to rimose or rimose-areolate, faintly yellow to pale yellowish green or yellow-gray thalli. The apothecia may be biatorine or lecanorine with typically epruinose or weakly pruinose discs that are concolorous or slightly darker than the thallus. The thalline exciple, if present, lacks larger crystals but is usually densely filled with small brownish granules that are insoluble in K. The yellowish tinge of thalli and apothecia is caused by the production of usnic acid, occasionally supplemented by xanthones.

Figures

FIGURE 15. Other species in the L. subfusca-group. A–C. Lecanora kalbii (Bungartz, F. 6432, CDS 34647–holotype). A. Coarsely granular to bullate areolate, white thallus with crenate lecanorine apothecia and blackened epruinose disc. B. Apothecial section (in water, DIC): exciple with large crystals only, not dissolving in K (pulicaris-type), epihymenium brownish black, lacking crystals; subhymenium distinctly developed, pale yellowish brown (cf. glabrata-type). C. Filiform conidia. D–E. Lecanora ombligulata (Bungartz, F. 7008, CDS 36515–holotype). D. ±Cerebriform, minutely peltate-umbilicate thallus with blackened apothecia. E. Apothecial section (in water, DIC): exciple filled with abundant, minute crystals (allophana-type), epihymenium bluish-black (gangaleoides-type). Scales: A & D = 5 mm; B & E = 100 µm; C =5 µm.

FIGURE 16. Species in the L. varia-group. A–G. Lecanora confusoides. A–B. Thallus variation on different substrates. A. Thick, rimoseareolate thallus with ±adnate apothecia, disc brown, in parts with a dark grayish tinge, distinctly pruinose, on fibrous bark of Cordia (Bungartz, F. 8833, CDS 45651–holotype). B. Thin, endosubstratal to rimose, abundantly blastidiate-sorediate thallus with ±immersed apothecia, the apothecial margin blastidiate-sorediate (Bungartz, F. 7207, CDS 37691). C. Filiform conidia (Bungartz, F. 8833, CDS 45651). D. Asci with narrowly oblong ascospores (Bungartz, F. 8833, CDS 45651). E–G. Apothecial sections (in water, DIC). E. Proper exciple well developed, abundantly inspersed with small, orange granules, thalline exciple below reduced (Bungartz, F. 6044, CDS 33723). F. Proper exciple well developed, sparsely interspersed with small, orange granules, thalline exciple below moderately developed (Bungartz, F. 8833, CDS 45651). G. Proper exciple well developed, sparsely interspersed with small, orange granules, thalline exciple along the outside well developed, but ±disintegrating (Bungartz, F. 8833, CDS 45651). Scales: A & B = 5 mm; C = 20 µm; D = 10 µm; E, F & G = 100 µm.

FIGURE 17. Species in the L. varia-group. A–E. Lecanora pyrrhosporoides. A–B. Thallus variation on different substrates. A. Thick, granular leproid thallus with ±immersed to sessile apothecia, disc brown to darkened, coarsely pruinose, lecanorine margin either dissolved into blastidiate granules or excluded below; on decorticated branches of Prosopis (Aptroot, A. 64140, CDS 30703). B. Thallus of scattered clusters of coarse coralline blastidiate granules, with scarce apothecia; on smooth bark of Bursera (Bungartz, F. 5359, CDS 28443). C–D. Apothecial sections (in water, DIC). C. Exciple appearing biatorine, almost completely reduced to a layer of pale brown cells extending from the epihymenium to the outer exciple; lecanorine part not developed (Aptroot, A. 64140, CDS 30703). D. Exciple ±lecanorine, with a thin, inner, proper exciple, surrounded by a thick, disintegrating, outer, thalline part (Aptroot, A. 64140, CDS 30703). E. Filiform conidia (Aptroot, A. 64140, CDS 30703). F–G. Lecanora subaureoides (Aptroot,A. 65158, CDS 31741–holotype). F. Dispersed thallus squamules with marginal soredia extruding granular soredia, apothecia malformed, not clearly differentiated from thallus squamules. G. Section of poorly developed lecanorine apothecium lacking asci or ascospores. Scales: A, B & F = 5 mm; C, D & G = 100 µm; E = 20 µm.