Carbacanthographis iriomotensis (M. Nakan.) M. Nakan. & Kashiw.

Jiang, Shu-Hao, Hao, Cheng-Yue, Zhao, Xin & Jia, Ze-Feng, 2024, New species and record in the genus Carbacanthographis (lichenized Ascomycota, Graphidaceae) from China, Phytotaxa 670 (4), pp. 285-292 : 289-290

Carbacanthographis iriomotensis (M. Nakan.) M. Nakan. & Kashiw. , in Nakanishi, Kashiwadani & Moon, Bull. natn.

Sci. Mus., Tokyo, B 29(2): 86 (2003) Fig. 3

Type:— JAPAN. Yaeyama Islands: Pref. Okinawa, Taketomi-cho, Isl. Iriomote, Ohara-Mt. Goza-dake, 30 m elev. 1979, M. Nakanashi 20738 ( HIRO – holotype).

FIGTURE 3. Carbacanthographis iriomotensis ( HMAS-L 115445); A, B. Thallus with prominent to sessile, laterally carbonized lirellae (scale = 1.0 mm). C. Apothecia section and warty periphysoids (scale = 100 μm). D. Apothecia section (in polarized light) showing with prominent patches of calcium oxalate crystals (scale = 100 μm). E–H. Asci (scale = 25 μm). I. Paraphyse (scale = 20 μm). J–N. Ascospore (scale = 10 μm).

Description: —Thallus crustose, corticolous, ecorticate, brownish, epiperidermal, continuous, smooth, dull, tightly attached to the substratum; lacking isidia and soredia; prothallus absent. Ascomata lirellate, prominent to sessile, straight or sinuous, scattered, elongate and irregularly branched, not striate, 1.5–3 mm long, 0.2–0.3 mm wide, terminally acute or rounded. Thalline margin distinct, completely covering the proper excipulum, with prominent patches of calcium oxalate crystals. Labia well developed, covered by a thick, white pruina, entire. Disc concealed, with slit-like appearance. Proper excipulum not striate, convergent, laterally carbonized, 30–45 μm thick laterally, 28.5–43.5 μm thick at the base. Hymenium hyaline, not inspersed, 95–105 μm high, I–. Hypothecium hyaline, 13.5–16 μm high. Paraphyses parallel, simple, septate, 1.5–2 μm wide, smooth at the tips. Periphysoids develop from the lateral proper excipulum, 3–3.5 μm wide, distinctly warty at the tips. Asci clavate, 8-spored, 63–74 × 14–18.5 μm. Ascospores hyaline, ellipsoidal, 5–9-septate, 22–37 × 5–8 μm, I+ blue, not surrounded by a gelatinous layer. Pycnidia not observed.

Chemistry and spot tests: —Thallus K+ yellow, C–, P+ orange, UV–. TLC: stictic acid.

Distribution and habitat: — Carbacanthographis iriomotensis is a rare corticolous species, previously known only from Japan (Nakanishi 1981), reported here for the first time from China. This species grows on bark at low altitudes in the tropical area of China, in association with Ocellularia sp. spreading around the tree trunks.

Notes: —The morphological and chemical characteristics of the specimens agree with the protologue (Nakanishi 1981), except for the shorter lirellae (1.5–3 mm vs. 1–5 mm) and the I+ ascospores. Due to the increasing frequency of the I+ ascospores in this genus, we do not wish to treat it as a new species, but rather as an intraspecific variation. This species is characterized by the elongate and irregularly branched lirellae with complete thalline margin, entire labia, a laterally carbonized proper exciple, a clear hymenium, transversely septate ascospores and the presence of stictic acid. It closely resembles C. marcescens , but differs in having transversely septate ascospores (Nakanishi 1981).

Materials examined: — China. Hainan Province: Ledong County, Jianfeng Ridge, Mingfeng Valley. 900 m elev., 109°6′0″E, 18°26′24″N, on bark, 26 July 2009, M. Liu HN09419 ( HMAS-L 115445).