Coenogonium geralense (P. Henn.) Lücking

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 : 112

Coenogonium geralense (P. Henn.) Lücking , Flora neotrop. Monogr. 103: 579 (2008). ( Fig. 6F )

Ombrophila geralensis P. Henn., Hedwigia 38 (Beibl.): 65 (1899); Dimerella flavicans Vězda & Farkas, Folia Geobot. Phytotax. 23: 189 (1988); Coenogonium flavicans (Vězda & Farkas) Kalb & Lücking, In : Lücking & Kalb, Bot. Jahrb. Syst. 122 (1): 32 (2000).—For further synonyms see Lücking (2008).

Thallus crustose, foliicolous, continuous, thin, smooth, yellowish green to grey green, 10–50 mm diam., without a distinct corticiform layer; prothallus thin, white or absent. Photobiont Trentepohlia , cells angular to rounded, mostly in irregular plates, partly short threads, cells 10–20 × 5–7 μm. Apothecia epiphyllous or marginally hypophyllous, sessile, rounded in outline, 0.4–0.8 mm diam., 125–175 μm high; disc plane, concave in young apothecia, pale to golden yellow; margin thin, prominent, smooth or slightly denticulate, concolorous with disc or paler, wax-colored or white. 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, 5–10 × 4–7 μm. Hypothecium 10–13 μm high, colorless to pale yellowish. Hymenium 50–60 μm high, colorless, I+ blue, then quickly reddish brown then greyish brown. Asci 45–55 × 6–7 μm. Ascospores irregularly biseriate, narrowly ellipsoid, 1-septate, 6–8 × 1.8–2.5 μm, 3–4 times as long as broad. Pycnidia common, applanately wart-shaped, 0.12–0.25 mm diam., yellowish green. Conidia ellipsoid, non-septate 3 × 1.7–2 μm. Chemistry: no substances detected by TLC.

Distribution and habitat:—Pantropical. Central America, South America, Africa, Thailand, Philippines and Australia. In Thailand, C. geralense (recorded as C. flavicans by Papong et al. 2007 and Neuwirth et al. 2014) is rare. It has been found at various places in Khao Yai National Park in the understory of tropical rainforests ( Papong et al. 2007) and mixed deciduous forests from 340– 830 m.

Remarks:— C. geralense is similar to C. dilucidum , but the latter species is distinguished by much broader and longer ascospores (6–12 × 2.5–3.5 μm). Also similar is C. siquirrense (Lücking) Lücking from the Neotropics, which differs in having orange apothecia with a darker marginal zone.

Material from Thailand examined:— Nakhon Ratchasima Province: near Nang Rong waterfall, in a mixed deciduous forests, 340 m, 14°20’31.93’’ N, 101°18’49.64’’ E, K. Papong RU-16969 ( RAMK 009055).

Figures

FIGURE 6. Habitus photographs of Coenogonium species. A. Coenogonium convexum (KK 41133), scale 1 mm. B. Coenogonium coronatum (KK 41136), scale 0.5 mm, scale of inlet 0.15 mm. C. Coenogonium dilucidum (KJ 41439), scale 0.25 mm. D. Coenogonium epiphyllum (RAMK 009100), scale 0.25 mm. E. Coenogonium frederici (Isotype, KK 41445), scale 0.5 mm. F. Coenogonium geralense (KK 41446), scale 1 mm.