THAILAND, Ubon Ratchathani Province, Pha Tam National Park, Sang Chan waterfall, 15°30'N, 105°35'E, 124 m, dry evergreen forest, on bark; 12 April 2013, K. Papong 8560 (holotype: MSUT; isotype: F).

Characterized within the genus by having submuriform ascospores.

The specific epithet refers to the country where the type specimen was collected.

Thallus endophloeodal to epiphloeodal, up to c. 120 µm thick, pale green to yellowish green, smooth. True cortex ±continuous, to c. 25 µm thick. Algal layer poorly to well developed, ±continuous; calcium oxalate crystals sparse to abundant, large and clustered; medulla usually distinct. Vegetative propagules not seen. Ascomata conspicuous, to c. 0.8–1.2 mm diam., often larger when fused, ±rounded to irregular, apothecioid to somewhat chroodiscoid, solitary to more often fused, becoming slightly to distinctly emergent, mostly irregularly or regularly urceolate. Disc usually partly visible from above, rarely completely exposed, pale yellowish to whitish green. Pores broad to gaping, to c. 0.6–08 mm wide, ±rounded to irregular, entire to slightly ragged; thalline exciple often becoming apically visible, rarely completely visible from above, ±free, whitish. Thalline rim margin broad to gaping, ±rounded, more commonly irregular, thick, entire, concolorous to whitish. Thalline exciple fused to partly or entirely free, thick, hyaline internally, pale yellowish or greenish marginally, with calcium oxalate crystals. Hymenium to c. 120 µm thick, clear, strongly conglutinated; paraphyses thick, irregular and often distoseptate, ±interwoven, with thickened irregular tips; lateral paraphyses absent; columella whitish and reticulate. Epihymenium hyaline, with fine crystals. Asci 8-spored; tholus initially thick, thin when mature, 100–110 × 10–12 µm. Ascospores submuriform with 3 × 0–1 septa, hyaline, slightly amyloid, 15–20 × 7.5 µm. Pycnidia not seen.

Figure 3. 

Morphology and anatomy of Glaucotrema thailandicum (A–E) A–B habitat of ascoma C cross-section of ascoma show whitish and reticulate columella D asci with spores and E submuriform ascospores (holotype), Ocellularia klinhomii (F–K) F–G ascomata immersed in verrucae and surrounded by a black ring H cross-section of ascoma with carbonized columella and apically carbonized exiple I–K ascus and ascospores (holotype). Scale bar A–B, F–G = 1 mm, H = 100 µm, C–D, I = 50 µm, E, J–K = 20 µm.

Thallus K+ yellowish, C–, P+ yellow; containing psoromic acid.

The new species was found in northeastern Thailand, growing on bark in a dry evergreen forest. It is known only from the type locality.

This new species is unique within the genus in having submuriform ascospores, whereas all other described species have transversely septate ascospores. In addition, the ascospores in G. bahianum, G. costaricense and G. stegoboloides are smaller than in the new species. Molecular data support the distinction of the new taxon. In morphology it resembles G. bahianum and G. stegoboloides.

THAILAND, Ubon Ratchathani Province, Pha Tam National Park, Sang Chan waterfall, 15°30'N, 105°35'E, 124 m, dry evergreen forest, on bark; 12 April 2013, K. Papong 8566 (holotype: MSUT; isotype: F).

Differing from the similar O. krathingensis in having a whitish grey, rimose thallus.

The specific epithet refers to the collector Mr. Winia Klinhom, mycologist from Thailand.

Thallus corticolous, epiperidermal, up to c. 5 cm diam., continuous; surface rimose, whitish grey, medulla white; prothallus absent. Thallus in section 30–40 µm thick, with prosoplectenchymatous cortex, 5–10 µm thick, photobiont layer 15–20 µm thick, and medulla 20–25 µm thick, with scattered clusters of calcium oxalate crystals. Photobiont Trentepohlia; cells rounded to irregular in outline, in irregular groups, green, 7–9 × 6–8 µm. Ascomata rounded, verrucae and surrounded by a black ring, erumpent to immersed, with complete thalline margin, 0.4–0.7 mm diam., 0.15–0.2 mm high; disc covered by 0.05–0.1 mm wide pore more or less filled with black-tipped columella but columella often immersed; proper margin indistinct, entire to slightly fissured, visible as whitish rim around the pore; thalline margin entire to slightly fissured, smooth, yellowish green. Excipulum entire, prosoplectenchymatous, brown with apically carbonized, 15–20 µm wide, fused with thalline margin and difficult to separate from the bordering periderm; laterally covered by algiferous, corticate thallus containing periderm layers; columella present, finger-like, carbonized, up to 100 µm broad and 120–140 µm high; hypothecium prosoplectenchymatous, 5–10 µm high, light brown; hymenium 125–150 µm high, hyaline, clear; epithecium indistinct, 5–7 µm high, hyaline. Paraphyses unbranched, apically smooth; periphysoids absent; asci cylindrical to narrowly clavate, 110–115 × 12–15 µm. Ascospores 8 per ascus, ellipsoid, 6–9-septate, 25–38 × 7–8 µm, hyaline, distoseptate with lens-shaped lumina, I+ violet-blue. Pycnidia not seen.

No substances detected by TLC.

The new species was collected in northeastern Thailand, growing on bark in a dry evergreen forest. It is known only from the type locality.

Similar in ascospore size, lack of secondary metabolites and only apically carbonized exciple to O. krathingensis but differing in having a whitish gray, rimose thallus with ascomata in verrucae and surrounded by a black ring, reminiscent of O. wirthii (Mangold et al. 2008). The latter species is readily distinguished by having a broader, carbonized columella and the presence of the psoromic acid chemosyndrome. The species would key out at alternative 60 in the Ocellularia key for Thailand (Sutjaritturakan and Kalb 2015).

THAILAND, Ubon Ratchathani Province, Pha Tam National Park, Sang Chan waterfall, 15°30'N, 105°35'E, 124 m, dry evergreen forest, on bark; 12 April 2013, K. Papong 8568, 8552, 8567, 8570, 8542, 8541, 8573, 8574 (MSUT), K. Papong 8557 (RAMK).

THAILAND, Ubon Ratchathani Province, Pha Tam National Park, Sang Chan waterfall, 15°30'N, 105°35'E, 124 m, dry evergreen forest, on bark; 12 April 2013, K. Papong 8574 (holotype: MSUT; isotype: F).

Differing from the similar O. krathingensis in having an a grayish, thick and rimose thallus.

The specific epithet refers to the name of the Pha Tam National Park in Ubon Ratchathani Province, Thailand.

Thallus corticolous, epiperidermal, up to c. 5 cm diam., continuous; surface uneven-verrucose to rimose, grayish, medulla white; prothallus absent. Thallus in section 60–75 µm thick, with prosoplectenchymatous cortex, 5–8 µm thick, photobiont layer 20–25 µm thick, and medulla 35–40 µm thick, with scattered clusters of calcium oxalate crystals. Photobiont Trentepohlia; cells rounded to irregular in outline, in irregular groups, green, 8–10 × 6–7 µm. Ascomata rounded, erumpent, with complete thalline margin, 0.4–0.7 mm diam., 0.15–0.2 mm high; disc covered by 0.07–0.1 mm wide pore more or less filled with black-tipped columella but columella often immersed; proper margin indistinct; thalline margin entire to slightly fissured, smooth, light yellowish green. Excipulum entire, prosoplectenchymatous, apically carbonized, 15–20 µm wide, fused with thalline margin and difficult to separate from the bordering periderm; laterally covered by algiferous, corticate thallus containing periderm layers; columella present, finger-like, carbonized, up to 110 µm broad and 120–135 µm high; hypothecium prosoplectenchymatous, 5–10 µm high, light brown; hymenium 120–150 µm high, hyaline, clear; epithecium indistinct, 5–10 µm high, hyaline. Paraphyses unbranched, apically smooth; periphysoids absent; asci cylindrical to narrowly clavate, 100–110 × 12–15 µm. Ascospores 8 per ascus, ellipsoid, 7–8-septate, 25–30 × 7.5–8 µm, hyaline, distoseptate with lens-shaped lumina, I+ violet-blue. Pycnidia not seen.

Figure 4. 

Morphology and anatomy of Ocellularia phatamensis (A–B) A habitat of ascomata B ascospores (K. Papong 8574, holotype MSUT!), O. rotundifumosa (C–E) C ascomata D hymenium with ascus and E ascospores (holotype MSUT), O. thailandica (F–H) F habitat of ascomata G ascus with ascospores and H ascospores (holotype). Scale bar A, C, F = 1 mm, D, G = 50 µm, B, E, H = 20 µm.

No substances detected by TLC.

The new species was collected in northeastern Thailand, growing on bark in a dry evergreen forest. It is known only from the type locality.

The new species is similar to O. krathingensis in having an apically carbonized exciple and columella, transversely septate, amyloid ascospores, and lacking secondary metabolites, but differs in having a grayish and thicker thallus (Homchantara and Coppins 2002). Another similar species is O. klinhomii, but differs in lacking a dark apothecial rim and the ascomata are not immersed in verrucae. Molecular data support the distinction of these two species (Fig. 2). Another similar and related species is O. diacida, which is readily distinguished by the presence of the hirtifructic acid chemosyndrome. The species would key out at alternative 60 in the Ocellularia key for Thailand (Sutjaritturakan and Kalb 2015).

THAILAND, Ubon Ratchathani Province, Pha Tam National Park, Sang Chan waterfall, 15°30'N, 105°35'E, 124 m, dry evergreen forest, on bark; 12 April 2013, K. Papong 8576 (holotype: MSUT; isotype: F).

Differing from O. fumosa in having ascospores with rounded ends.

The specific epithet refers to the ascospore shape with rounded ends and to the similarity with O. fumosa.

Thallus corticolous, endophloeodal to epiphloeodal, up to c. 200 µm thick, greenish gray to olive, slightly glossy, smooth, rarely continuous to usually ±verrucose. True cortex discontinuous, to c. 15 µm thick, formed by irregular hyphae. Algal layer well developed, continuous; calcium oxalate crystals moderately large, scattered. Photobiont Trentepohlia; cells rounded to irregular in outline, in irregular groups, green, 7–9 × 6–9 µm. Vegetative propagules not seen. Ascomata rounded with complete thalline margin, 0.4–0.9 mm diam., solitary to marginally fused, immersed to rather emergent, then verrucose-hemispherical to urceolate. Disc with the columella visible from above, entire, free, slightly pruinose, dark gray. Pores formed by the thalline rim margin, c. 0.5 mm diam., the apex of the proper exciple becoming visible from above as a brownish to dark gray line, moderately thick, concolorous with the thallus or brighter; thalline rim incurved. Proper exciple fused, dark brown to carbonized marginally and towards the tips, usually distinctly amyloid at the base. Hymenium to c. 150 µm thick, densely inspersed, distinctly conglutinated; paraphyses slightly bent, ±interwoven, unbranched, with moderately thickened tips; columellar structures moderately well developed, to 150 µm wide, entire, the upper parts brownish to carbonized. Epihymenium brownish, with grayish or brownish granules. Asci 8-spored; tholus initially thick, thin when mature. Ascospores 7–9-septate, fusiform to oblong-fusiform, rarely clavate, with rounded ends, 24–35 × 7–10 µm, hyaline, distoseptate with lens-shaped lumina, I+ violet-blue. Pycnidia not seen.

No compounds detectable by TLC.

The new species was collected in northeastern Thailand, growing on bark in a dry evergreen forest. It is known only from the type locality.

Similar to O. fumosa, but differing in having rounded ends of the ascospores instead of acute ones in O. fumosa. Molecular data support the distinction of the species (Fig. 2). Characters to separate the related O. natashae and O. thryptica are discussed above. The species would key out at alternative 23 in the Ocellularia key for Thailand (Sutjaritturakan and Kalb 2015).

THAILAND, Ubon Ratchathani Province, Pha Tam National Park, trail to Huai Sanom, 15°27'N, 105°34'E, 245 m, dry evergreen forest, on bark; 12 April 2013, K. Papong 8458 (holotype: MSUT; isotype: F).

Differing from the similar O. viridipallens in having broader ascospores with up to 7 septa.

The specific epithet refers to the country where the type specimen was collected.

Thallus corticolous, epiperidermal, up to c. 5 cm diam., continuous; surface uneven-verrucose to rimose, light yellowish green, medulla white; prothallus absent. Thallus in section 40–60 µm thick, with prosoplectenchymatous cortex, 5–7 µm thick, photobiont layer 15–25 µm thick, and medulla 20–30 µm thick, with scattered clusters of calcium oxalate crystals. Photobiont Trentepohlia; cells rounded to irregular in outline, in irregular groups, green, 7–8 × 5–9 µm. Ascomata rounded, erumpent, with complete thalline margin, 0.3–0.5 mm diam., 0.12–0.2 mm high; disc covered by 0.05–0.1 mm wide pore; proper margin indistinct, entire to slightly fissured, visible as whitish rim around the pore; thalline margin entire to slightly fissured, smooth, light yellowish green. Excipulum entire, prosoplectenchymatous, brown to dark brown, 15–20 µm wide, fused with thalline margin and difficult to separate from the bordering periderm; laterally covered by algiferous, corticate thallus containing periderm layers; columella present, finger-like, carbonized, up to 100 µm broad and 120–135 µm high; hypothecium prosoplectenchymatous, 5–10 µm high, hyaline; hymenium 125–140 µm high, hyaline, clear; epithecium indistinct, 5–10 µm high, hyaline. Paraphyses unbranched, apically smooth; periphysoids absent; asci cylindrical to narrowly clavate, 87–100 × 12–15 µm. Ascospores 8 per ascus, ellipsoid, 5–7-septate, 20–23 × 7–8 µm, hyaline, distoseptate with lens-shaped lumina, I+ violet-blue. Pycnidia not seen.

No substances detected by TLC.

The new species was collected in northeastern Thailand, growing on bark in a dry evergreen forest. It is known only from the type locality.

This new species is closely related to O. albocincta (Fig. 2). However, this species differs in lacking a columella (Papong et al. 2010). Morphologically it resembles O. viridipallens, which differs in having narrower ascospores. The species would key out at alternative 60 in the Ocellularia key for Thailand (Sutjaritturakan and Kalb 2015).

THAILAND, Ubon Ratchathani Province, Pha Tam National Park, trail to Huai Sanom, 15°27'N, 105°34'E, 245 m, dry evergreen forest, on bark; 12 April 2013, K. Papong 8439 (MSUT).

THAILAND. Ubon Ratchathani Province: Pha Tam National Park, trail to Huai Sanom, 15° 27’ 620” N, 105° 34’ 615” E, 245 m, dry evergreen forest, on bark; 12 Apr. 2013, K. Papong 8479 (epitype MSUT!).

In order to clarify the application of the name Ocellularia krathingensis, we propose an epitype for this species that agrees morphologically well with the holotype (RAMK!) and has been sequenced.

THAILAND, Ubon Ratchathani Province, Pha Tam National Park, trail to Huai Sanom, 15°27'N, 105°34'E, 245 m, dry evergreen forest, on bark; 12 April 2013, K. Papong 8496, 8478, 8483 (F, MSUT) (Figure 5A–C).

Figure 5. 

Morphology and anatomy of O. krathingensis (A–F); A habitat of ascomata B hymenium with ascus and C ascospores. (D–F) D erumpent ascomata E ascus and F ascospores A–C K. Papong 8483D–F K. Papong 8479 (epitype). Scale bar A, D = 1 mm, B, E = 50 µm, C, F = 20 µm.