Coenogonium nepalense (G. Thor & Vězda) Lücking, Aptroot & Sipman

Kalb, Jutarat, Boonpragob, Kansri & Kalb, Klaus, 2016, New Coenogonium species (Ostropales: Coenogoniaceae) from Thailand, new reports and a revised key to the species occurring in the country, Phytotaxa 283 (2), pp. 101-122 : 115-116

Coenogonium nepalense (G. Thor & Vězda) Lücking, Aptroot & Sipman , Fungal Diversity 23: 297 (2006). ( Fig. 8A )

Dimerella nepalensis G. Thor & Vězda, Folia Geobot. Phytotax. 19: 74 (1984).

Thallus crustose, corticolous, continuous, thin, smooth, grey to greenish grey, dull or partly shiny, up to 50 mm diam., with a distinct hyaline, paraplectenchymatic corticiform layer in part, 5–12 μm thick; prothallus absent. Photobiont Trentepohlia , cells angular to rounded, mostly in short threads, cells 8–14 × 7–12 μm. Apothecia sessile, rounded, 0.4– 0.8 mm diam., 190–210 μm high; disc plane, to slightly convex, concave in younger apothecia, orange-yellow to orange; margin distinct, slightly prominent or depressed with age, ochre to cream-colored. Excipulum paraplectenchymatous with irregularly arranged cells, 50–70 μm broad, outer part I+ yellow-brown, inner part I–; cells globose to elongate, thin- or partly thick-walled, 3–8 × 3–7 μm. Hypothecium 10–15 μm high, colorless to pale yellowish. Hymenium 70–80 μm high, colorless, I+ blue then quickly greyish brown, then reddish brown. Asci 65–75 × 6–8 μm. Ascospores biseriate, fusiform to oblong-ellipsoid, 1-septate, 7–13 × 2.0–3.0 μm, 2.8–5.2 times as long as broad. Pycnidia not seen. Chemistry: no substances detected by TLC.

Distribution and habitat:—Occurs in the Neotropics and eastern Paleotropics, e. g. Nepal, Thailand, Australia. It grows on the bark of various trees (e. g. Micromelum sp. ) in dry Dipterocarp forests, tropical rainforests, secondary forests, dry evergreen forests and hill evergreen forests from 30–1400 m, thus exhibiting a broad ecological range.

Remarks:— C. nepalense belongs to a difficult group of species, centered around C. luteum and C. convexum . It is distinguished from C. luteum by having smaller apothecia (0.5–2 mm diam. and 200–300 μm high in C. luteum ) and asci with biseriate ascospores (uniseriate in C. luteum ) and ascospores with a larger LWQ (2.4–3.6 in C. luteum ), resulting in a different shape (fusiform to oblong-ellipsoid vs. broadly ellipsoid in C. luteum ). For the differences to C. convexum see under that species. The specimen from Australia mentioned below is a new addition to the lichen biota of this country.

Material examined:— THAILAND. Chiang Mai Province: Mae Rim district, in a dry Dipterocarp forests along a big pond called Huay Tueng Tao Reservoir, ca. 6 km NNW of Chiang Mai, 360 m, 18°52’11’’ N, 98°56’28’’ E, 16 March 2008, K. Kalb, K. Buaruang & S. Jariangprasert (herb. K. Kalb 36985); ibid. Doi Suthep-Pui National Park, Khao San Ku, in hill evergreen forests along Huai Kaew road, 1400 m, 18°48’58.29’’ N, 98°54’0.11’’ E, 18 November 2001, K. Boonpragob KBSS 1 ( RAMK 027814); Nakhon Ratchasima Province: Khao Yai National Park; in a hill evergreen forests, at the top of Khao Nom Nang, 1055 m, 14°31’3.30’’ N, 16°40’40’’ E, 29 June 2000, J. Sutjaritturakan RU-20472 ( RAMK 003521); ibid., in a tropical rainforest along Pha Klua Mai nature trail to Heo Suwat waterfall, 760 m, 14°26’7.19’’ N, 101°24’25.81’’ E, 14 February 2008, W. Polyiam RU-22518 ( RAMK 008273); ibid., secondary forests at Nhong Khing, 815 m, 14°25’7.07’’N, 101°22’18.48’’ E, 15 January 1999, C. Thunyagun RU-10202 ( RAMK 003016); ibid. in a secondary forests at reforestation area of Nhong Khing, 830 m, 14°25’7.29’’ N, 101°22’18.52’’ E, 23 June 1999, C. Thunyagun RU-12401 ( RAMK 006720); ibid., Bhan TV site, in a dry evergreen forests, 760 m, 14°25’43.56’’ N, 101°22’54.42’’ E, 16 June 1999, C. Thunyagun RU-14608 ( RAMK 003015); ibid., hill evergreen forests SE of main road 3077 between the park headquarter and Khao Khieo, 1393 m, 14°21’39.90’’ N, 101°23’35.19’’ E, 31 October 1997, W. Khamtim RU-9145 ( RAMK 008162); ibid., in a tropical rainforest along trail from main road 2090 to Pha Tabaek waterfall, 570 m, 14°21’54.03’’ N, 101°19’8.46’’ E, 9 January 1999, K. Khamtim RU-12230 ( RAMK 006836); ibid., in a tropical rainforest along trail from Nhong Prue to Check Point 19 khao Leam substation, 820 m, 14°26’01.1’’ N, 101°25’01.8’’ E, 23 April 2000, K. Noicharoen RU-18732 ( RAMK 004466).— AUSTRALIA. Queensland: Sunshine Coast; Noosa Heads, in a coastal tropical rainforest with Casuarina cunninghamiana, Syzygium spec., Archonthophoenix cunninghamiana, Asplenium nidus, Platycerium bifurcatum etc., 30 m, 26°23’02’’ S, 153°05’ 50’’ E, 20 August 1992, K. Kalb (herb. K. Kalb 35180).

Figures

FIGURE 8. Habitus photographs of Coenogonium species. A. Coenogonium nepalense (KK 35180), scale 1 mm. B. Coenogonium pineti (KK 38905), scale 0.3 mm. C. Coenogonium queenslandicum (KK 41131), scale 0.5 mm. D. Coenogonium subborinquense (KK 38820) thallus with apothecia and pycnidia (arrow), scale 1 mm. E. Coenogonium subluteum (KK 39803), scale 0.5 mm. F. Coenogonium verrucimarginatum (KJ 41288), scale 0.25 mm.