Pyrenula apiculata 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

3. Pyrenula apiculata M.Z. Dou & Z.F. Jia sp. nov.

Fig. 4

Diagnosis.

The new species can be distinguished from the most similar species Pyrenula bahiana by the absence of endospore layers in the spore tips and the absence of pseudocyphellae.

Type.

China. Yunnan Province: Mengla County, Xishuangbanna Tropic Botanical Garden, Chinese Academy of Sciences , Green Stone Forest , Buttress Roots , 21°54′39′′N, 101°17′05′′ E, alt. 672 m, on bark, 26 January 2018, X. Zhao YN18172 (LCUF: holotype: YN18172; GenBank OR 578592 for ITS and OR578573 for LSU) .

Description.

Thallus corticolous, crustose, olive-green, corticate without pseudocyphellae, UV-. Ascomata perithecioid, emergent, dispersed, conical, flattened, 0.3-0.5 mm diam., with crystals, the sides partly covered by the thallus, KOH-. Ostioles apical, black. Hamathecium not inspersed, IKI-. Ascospores 8 per ascus, uniseriate, with gelatinous halo before becoming old, 3-septate, 18-34 × 10-15 μm; middle lumina triangular to round, end lumina triangular, without layer of endospore in the spore tips; hyaline when young, reddish-brown when mature, over-mature ascospores with red oil.

Chemistry.

Thallus K-, C-, KC-, UV-, hamathecium IKI-.

Ecology and distribution.

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

Etymology.

The specific epithet apiculata refers to the pointed bulge of the end locules of ascospores.

Additional specimens examined.

China. Yunnan Province: Mengla County, Xishuangbanna Tropic Botanical Garden, Chinese Academy of Sciences , Green Stone Forest , Buttress Roots , 21°54′39′′N, 101°17′05′′E, alt. 672 m, on bark, 26 January 2018, X. Zhao YN18173 (LCUF, GenBank for ITS and for LSU), same locality, YN18174 ; China.

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. It differs from P. thailandica by the absence of pseudocyphellae, the absence of endospore layers in the spore tips and reddish-brown and smaller ascospores, which measure in the latter (30-)35-51 × (10-)14-20 μm ( Aptroot 2012; Aptroot et al. 2012, 2013; Ingle et al. 2018). This new species differs from P. bahiana by the reddish-brown ascospores when mature, absence of endospore layers in the spore tips and absence of pseudocyphellae ( 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 4. Pyrenula apiculata (LCUF YN 18172) A, B thallus with apothecia C-E over-mature ascospores with red oil F-I ascospores at different developmental stages, red arrow in F shows gelatinous sheath. Scale bars: 2 mm (A); 1 mm (B); 5 μm (C, E, I); 10 μm (D, F, H); 20 μm (G).