Pyrenula thailandicoides M.Z. Dou & Z.F. Jia, 2024

Dou, Mingzhu, Liu, Shengnan, Li, Jiechen, Aptroot, Andre & Jia, Zefeng, 2024, Three new Pyrenula species with 3 - septate ascospores with red or orange oil when over-mature (Ascomycota, Pyrenulales, Pyrenulaceae) from China, MycoKeys 102, pp. 107-125 : 107

2. Pyrenula thailandicoides M.Z. Dou & Z.F. Jia sp. nov.

Fig. 3

Diagnosis.

The new species can be distinguished from the most closely-related species Pyrenula thailandica by the IKI+ red hamathecium and an unidentified lichen substance.

Type.

China. Yunnan Province: Mengla County, Xishuangbanna Tropic Botanical Garden, Chinese Academy of Sciences , Rainforest Valley , 21°54′51′′N, 101°11′28′′E, alt. 626 m, on bark, 26 January 2018, X.H. Wu YN18212 (LCUF: holotype: YN18212; GenBank OR 578589 for ITS and OR578570 for LSU) .

Description.

Thallus corticolous, crustose, olive-green, corticate with few pseudocyphellae, UV-. Ascomata perithecioid, emergent, dispersed, conical, 0.8-1.6 mm diam., with crystals, KOH-. Ostioles apical, white, 0.25-0.45 mm. Hamathecium not inspersed (close-up in Suppl. material 3), IKI+/I+ red (Fig. 2 and Suppl. material 4). Ascospores 8 per ascus, irregularly biseriate, with gelatinous halo before becoming old, 3-septate, (30-)35-55 × (12-)15-23 μm; middle lumina diamond-shaped, end lumina triangular, with a thick layer of endospores in the spore tips; hyaline when young, reddish-brown when mature, over-mature ascospores with red oil.

Chemistry.

Thallus K+ orange-brown, C-, KC+ yellow, UV-, hamathecium IKI+ red, TLC showed an unidentified substance at Rf four of solvent C (Suppl. material 5).

Ecology and distribution.

The new species is currently only known from the tropical and subtropical regions of southern China on bark.

Etymology.

The specific epithet thailandicoides refers to the similarity to Pyrenula thailandica .

Additional specimens examined.

China. Yunnan Province: Mengla County, Xishuangbanna Tropic Botanical Garden, Chinese Academy of Sciences , 21°55′37′′N, 101°15′27′′E, alt. 555 m, on bark, 25 January 2018, X. Zhao YN18015 (LCUF; YN18015; GenBank OR 578590 for ITS and OR578571 for LSU) . China. Fujian Province: Longyan City, Dongxiao National Forest Park, Frog Stone , 24°58′07′′N, 117°01′14′′E, alt. 679 m, on bark, 12 July 2022, Z.G. Ma FJ220208 (LCUF; GenBank OR 578593 for ITS) .

Notes.

This new species is similar to Pyrenula thailandica , P. bahiana and P. concastroma in having 3-septate ascospores with red or orange oil when over-mature. The colour reaction of hamathecium of Pyrenula species in IKI is negative (such as Pyrenula thailandica and P. bahiana ) or IKI+ red/orangish (such as P. concastroma ) or IKI+ blue (such as P. massariospora ). This new species differs from P. thailandica by its IKI+ red hamathecium and an unidentified lichen substance ( Aptroot 2012; Aptroot et al. 2012, 2013; Ingle et al. 2018). This new species differs from P. bahiana by its IKI+ red hamathecium, an unidentified lichen substance and larger ascospores, the latter 26-33(-35) × 10-13(-15) μm ( Malme 1929; Aptroot 2012; Aptroot et al. 2013; Ingle et al. 2018). P. concastroma differs from the new species by the mostly aggregated ascomata with fused walls, but separate ostioles ( Aptroot 2012; Schumm and Aptroot 2021).

Figures

Figure 2. Pyrenula inspersa (LCUF HN 17058) A thallus with apothecia B apothecia and pseudocyphellae C, F-H ascospores at different developmental stages, over-mature ascospores with orange-oil can be seen in C, F and H D section of apothecium E section visualised with polarised light showing cortex of apothecium with crystals, red stars in D-H show the inspersion in hamathecium I-K young ascospores, red arrows show gelatinous halo. Scale bars: 2 mm (A); 1 mm (B); 10 μm (C, I); 200 μm (D, E); 50 μm (F, H); 35 μm (G); 20 μm (J, K).

Figure 3. Pyrenula thailandicoides (LCUF YN 18212) A, B thallus with apothecia C, D ascospores at different developmental stages, over-mature ascospores with red-oil can be seen in C, red arrows in D show gelatinous halo E IKI + red hamathecium. Scale bars: 2 mm (A); 1 mm (B); 30 μm (C); 20 μm (D); 50 μm (E).