Cryptophaea phaeospora Van den Broeck & Ertz, 2016

Broeck, Dries Van Den & Ertz, Damien, 2016, Cryptophaea, a new genus of byssoid Arthoniaceae (lichenized Ascomycota) and its phylogenetic position, Phytotaxa 261 (2), pp. 168-176 : 171-172

Cryptophaea phaeospora Van den Broeck & Ertz , sp. nov. ( Fig. 1 )

MycoBank #MB 816628

Sequence accessions: KX077540 (mtSSU, Van den Broeck 5964); KX077542 (RPB2, Van den Broeck 5964); KX077541 (mtSSU, Van den Broeck 5809); KX077543 (RPB2, Van den Broeck 5809)

Similar to some species of Cryptothecia and Herpothallon , but with tomentose brownish ascomata, (sub)muriform ascospores of 9–13 × 6–8 μm and with the presence of parietin.

Type: — DEMOCRATIC REPUBLIC OF THE CONGO. Orientale Province: Tshopo District, Yangambi, free standing tree in a garden along the road between the herbarium of Yangambi and the WWF, on an unidentified tree species, 436 m, 0°45’40” N, 24°29’53” E, 13 November 2013, Van den Broeck 5964 (holotype BR!).

Thallus corticolous, crustose, firmly attached to the substrate, whitish grey-green, slightly byssoid, continuous, pseudoisidia or pseudoisidoid structures absent, ca. 20–40 μm thick, hydrophobic; a reddish borderline observed in contact with other lichens, otherwise prothallus distinct, byssoid, white, composed mainly of interwoven and radiating hyphae. Photobiont trentepohlioid (I+ dark blue), in unbranched or branched chains of angular-rounded cells, 7–30 × 4–7.5 μm, abundant within the ascigerous areas and often visible as white to brownish hair like structures on the ascomata. Ascomata distinctly visible as ± regularly rounded to irregularly elongate ascigerous areas, abundant, not evenly dispersed, brownish, tomentose, emergent, convex, hydrophobic, 0.2–1.2 × 0.15–0.5 mm; young ascomata covered or surrounded by a bright orange pruina. Excipulum not observed. Hymenium not inspersed, 60–90 μm tall, I–, KI–. Interascal filaments few, throughout hyaline, branched, wavy, 1.1–2.7 μm wide, not widening or coloured at tips. Hypothecium not observed. Epihymenium not observed. Asci obovoid to ellipsoid, without a distinct ocular chamber, 20–30 × 10–18 μm (N = 5), I–, KI–, Arthothelium - type. Ascospores 9–13 × 6–8 μm (N = 50), hyaline, soon becoming greyish to brownish without ornamentation and with a dark wall of 0.3–0.5 μm thick, mostly brown septa and some brown darker spots, ellipsoid, 8/ascus, (sub)muriform, 6–9 loculate, locules ± rounded, upper and lower terminal cells often larger and undivided, with hyaline perispore, ca. 0.5 μm, I–, KI–. Pycnidia not observed.

Secondary chemistry: —Thallus K–, C–, KC–, PD –, UV –; apothecial sections K–, except for young ascomata surrounded or covered by an orange K+ purplish pruina; medulla I–; calcium oxalate crystals not observed after treatment with H 2 SO 4. TLC (solvents B’, C and G) revealed the presence of three substances: an UV + bright yelloworange spot before heating, corresponding to parietin (an anthraquinone), and two unknown substances: an UV + pinkish-red spot before and after heating, and a second substance visible in short wavelength ultraviolet light before heating.

Etymology:—The name phaeospora refers to the brown colour of the ascospores.

Distribution and ecology: — Cryptophaea phaeospora is presently known only from the village of Yangambi situated in the Congo basin, where it was collected in two localities that are close to each other. The species grows on the bark of free standing exposed trees in gardens close to the road. The species was not encountered in dense tropical forest along the Congo River and is thus probably absent in more shady habitats. The presence of parietin, known for his photoprotective role at UV-B and/or blue wavelengths ( Gauslaa & Ustvedt 2003), is also indicative of a species growing in exposed conditions.

Additional specimen examined (paratype): — DEMOCRATIC REPUBLIC OF THE CONGO. Orientale Province: Tshopo District,Yangambi, free standing tree in the garden of the herbarium of Yangambi, on an unidentified tree species, 440 m, 0°45’33” N, 24°29’47” E, 10 November 2013, Van den Broeck 5809 (paratype BR!).

Figures

FIGURE 1. Cryptophaea phaeospora (holotype). A. Habitat: well exposed trees in a garden. B. Morphology of the thallus and ascomata (scale = 1 mm). C. Ascus with young hyaline ascospores in water (scale = 10 μm). D. Ascospores in water (scale = 10 μm).