Huriella aeruginosa B.G. Lee & J.-S. Hur, 2021

Lee, Beeyoung Gun & Hur, Jae-Seoun, 2021, Two new calcicolous caloplacoid lichens from South Korea, with a taxonomic key to the species of Huriella and Squamulea, MycoKeys 84, pp. 35-55 : 35

Huriella aeruginosa B.G. Lee & J.-S. Hur sp. nov.

Fig. 7

Diagnosis.

Huriella aeruginosa differs from ' Squamulea ' Squamulea chelonia by dark greenish-grey to grey thallus without pruina (vs. yellow orange to deep orange thallus with white pruina), gold to yellow-brown epihymenium (vs. orange epihymenium), larger ascospores (7.5-12 × 4.5-7.5 μm vs. 8-10.4 × 4.7-6.0 μm) and the chemistry (thallus K-, KC- and no substance vs. thallus K+ purple, KC ± purplish and the presence of parietin, teloschistin, fallacinal, parietinic acid and emodin).

Type.

South Korea, Gangwon Province, Gangneung, Okgye-myeon, Mt. Seokbyung (summit), 37°35.21'N, 128°53.87'E, 1,072 m alt., on calcareous rock, 17 June 2020, B.G.Lee & H.J.Lee 2020-000872, with Bagliettoa baldensis , Catillaria lenticularis , Endocarpon subramulosum Y. Joshi & Hur, Laundonia flavovirescens , Rusavskia elegans and Verrucaria nigrescens (holotype: BDNA-L-0001072!; GenBank MW832829 for ITS) .

Thallus saxicolous (calcicolous), crustose, mainly areolate or slightly rimose, placodioid around edge, but without distinct lobes, thin, dark greenish-grey to grey, occasionally pale yellowish-grey when young, margin indeterminate or determinate when placodioid areoles are arranged around edge, vegetative propagules absent, areoles 0.3-0.7 mm diam., 150-200 μm thick; cortex hyaline with dark green pigment layer, 15-25 μm thick, cortical cells granular, coarsely anticlinally arranged, 5-10 μm diam., with epinecral layer, up to 5 μm thick; medulla 80-100 μm thick, below algal layer, with large crystals (materials of substrate possibly) and brown cells (dead algal cells possibly); photobiont coccoid, cells globose to oval, 5-25 μm. Small crystals in cortex, medulla and between algal cells, dissolving in K. Prothallus absent.

Apothecia abundant, scattered and not concentrated in centre, rounded, often contiguous when mature, emerging on the surface of thallus, immersed, adnate or rarely sessile, constricted at the base, 0.2-0.4 mm diam. Disc flat when young and flat or slightly convex when mature, not pruinose, orange from the beginning, 110-230 μm thick; margin persistent, even to disc or slightly prominent, generally entire or slightly crenulate, thalline margin concolorous to disc, proper margin inconspicuous. Amphithecium well-developed, with small crystals between algal cells, dissolving in K, 50-55 μm wide laterally, algal layers continuous to the base or solitarily remaining in amphithecium, algal cells 5-25 μm diam., cortical layer hyaline with gold to yellow-brown pigment concolorous to epihymenium at periphery, 15-20 μm thick. Parathecium inconspicuous, hyaline but gold to yellow-brown at periphery, ca. 10 μm wide laterally and ca. 20 μm wide at periphery. Epihymenium gold to yellow-brown, granular, pigment K+ wine red and dissolved, 10-20 μm high. Hymenium hyaline, 45-55 μm high. Hypothecium hyaline, 35-45 μm high. Oil droplets present, small, along paraphyses and more in the base of hymenium and hypothecium. Paraphyses septate, anastomosing, 2-3 μm wide, simple or branched at tips, tips swollen or slightly swollen, not pigmented, 3.5-5.5 μm wide. Asci clavate, 8-spored, 35-48 × 14-17 μm (n = 5). Ascospores generally ellipsoid, occasionally globose, 1-septate, polarilocular or narrow septum remaining, hyaline permanently, 7.5-12 × 4.5-7.5 μm (mean = 9.9 × 5.7 μm; SD = 0.9(L), 0.6(W); L/W ratio 1.2-2.3, ratio mean = 1.8, ratio SD = 0.2; n = 104), globose spores 7.5-9 × 7.0-9.2 μm (mean = 8.0 × 7.7 μm; SD = 0.8(L), 0.9(W); L/W ratio 1.0-1.1, ratio mean = 1.0, ratio SD = 0.1; n = 11). Pycnidia not detected.

Chemistry.

Thallus K-, KC-, C-, Pd-. Apothecia K+ wine red. Epihymenium K+ wine red. Epihymenium and hymenium I+ blue. UV-. No lichen substance was detected by TLC.

Distribution and ecology.

The species occurs on the calcareous rock. The species is currently known from the type collection.

Etymology.

The species epithet indicates the lichen’s thallus colour, dark green, which is the key characteristic distinguished from all the species in the genus Huriella .

Notes.

The morphological classification of the new species is not clear between Huriella and Squamulea because the new species has some characteristics for the former genus and others for the latter, i.e. the new species represents mainly areolate thallus without lobed margin and smaller apothecia for the former, whilst showing some squamulose thallus and wider ascospores for the latter (Table 2 ). The molecular results concluded the new species classification into the former genus, Huriella .

The new species is unique with the key characteristics of green pigmented thallus (with a distinct green layer in a section) and the substrate preference to calcareous rocks amongst all Huriella species.

The new species is similar to ' Squamulea ' Squamulea chelonia , Squamulea galactophylla ,' Squamulea ' Squamulea humboldtiana , S. parviloba and S. subsoluta in the substrate preference to calcareous rocks. However, the new species is different from ' Squamulea ' Squamulea chelonia by dark greenish-grey to grey thallus without pruina (vs. yellow orange to deep orange thallus with white pruina), gold to yellow-brown epihymenium (vs. orange epihymenium), larger ascospores (7.5-12 × 4.5-7.5 μm vs. 8-10.4 × 4.7-6.0 μm) and the chemistry (thallus K-, KC- and no substance vs. thallus K+ purple, KC ± purplish and the presence of parietin, teloschistin, fallacinal, parietinic acid and emodin) ( Bungartz et al. 2020).

The new species differs from S. galactophylla by thallus colour (dark greenish-grey to grey vs. dirty white to yellowish-brown), flat to convex disc (vs. flat disc only), yellowish-orange apothecia (vs. cinnamon-brown apothecia), smaller ascospores (7.5-12 × 4.5-7.5 μm vs. 10-15 × 5-7 μm) ( Fink 1935; Arup 2013).

The new species is distinguished from‘ Squamulea ' Squamulea humboldtiana by dark greenish-grey to grey thallus without pruina (vs. yellow-orange to deep orange thallus with pruina), absence of prothallus (vs. presence of prothallus), larger ascospores (7.5-12 × 4.5-7.5 μm vs. 8.1-9.9 × 4.8-5.9 μm) and the chemistry (thallus K-, KC- and no substance vs. thallus K+ purple, KC ± purplish and the presence of parietin, teloschistin, fallacinal, parietinic acid and emodin) ( Bungartz et al. 2020).

The new species differs from S. parviloba by dark greenish-grey to grey thallus (vs. yellow-orange to orange thallus), absence of lobes (vs. short narrow elongated lobes around edge), convex and yellow-orange disc (vs. flat and deep orange disc), smaller ascospores (7.5-12 × 4.5-7.5 μm vs. 11-14 × 5.5-7 μm) and the chemistry (thallus K- vs. thallus K+ red) ( Wetmore 2003; Nash III TH et al. 2007).

The new species is different from S. subsoluta by dark greenish-grey to grey thallus (vs. yellow-orange, orange to reddish-orange thallus), absence of prothallus (vs. black prothallus), flat to convex, yellow-orange apothecia (vs. flat to concave, deep orange apothecia) and the chemistry (thallus K- and no substance vs. thallus K+ red, the presence of parietin, fallacinal, emodin and teloschistin) ( Wetmore 2003; Nash III TH et al. 2007).

The most distinctive characteristic of the new species is the thallus colour, i.e. dark greenish-grey to grey, which is different from all comparable calcicolous species in the genus Squamulea .

Figures

Figure 7. Huriella aeruginosa (BDNA-L- 0001072, holotype) in morphology A-C habitus and apothecia. Thallus dark greenish-grey to grey with no pruina. Thalline margin of apothecia concolorous to disc D apothecia adnate or rarely sessile. Amphithecium well-developed, but parathecium inconspicuous. E thallus with dark green pigment layer under cortex F-G clavate asci containing 8 - spores H ascospores generally ellipsoid, but occasionally globose, developing polarilocular in both types. Two blue coloured spores in lactophenol cotton blue. Scale bars: 1 mm (A-C); 100 μm (D); 10 μm (E-H).