Coniocarpon cinnabarinum DC.

Frisch, Andreas, Grube, Martin, Kashiwadani, Hiroyuki & Ohmura, Yoshihito, 2018, Arthoniaceae with reddish, K + purple ascomata in Japan, Phytotaxa 356 (1), pp. 19-33 : 26-28

Coniocarpon cinnabarinum DC. in Lamarck & Candolle (1805: 323).

Arthonia cinnabarina (DC.) Wallroth (1831: 320) .— Type: [ France]. «Croit sur le charme» (not selected).

= Sphaeria gregaria Weigel (1772: 43) .— Arthonia gregaria (Weigel) Körber (1855: 291) , non Arthonia gregaria Fée (1825: 50) ; Coniocarpon gregarium (Weigel) Schaerer (1821: 34) ; Spiloma gregarium (Weigel) Turner & Borrer in Smith (1833: 167). — Type: [ Germany, Greifswald]. «In Ceraso frequentem legi nuperrime fine Februarii” (not selected).

= Spiloma? tumidula Acharius (1803: 11) .— Arthonia tumidula (Ach.) Acharius (1806: 3) .—Type: [ Spain]. Hispania, habitat in cortice Quercus cocciferae . Schousboë s.n., s.d. (H-Ach! holotype; BM (microscopical preparation)! isotype).

Taxonomic note.— Sphaeria gregaria Weigel is the oldest valid name for this lichen and, though not available in Arthonia due to the older homonym A. gregaria Fée , the specific epithet could be used in Coniocarpon . However, Sphaeria gregaria is accepted as a synonym of Coniocarpon cinnabarinum in the index to the Systema Mycologicum ( Fries 1832: 166), and we agree with Hawksworth (1986: 788) that the name C. cinnabarinum should be considered as sanctioned according to article 31.1 (d) ICN ( McNeill et al. 2012). Fig. 3B

THALLUS pale olive grey, matt to weakly glossy, continuous, smooth, in section up to 0.1 mm tall, largely endophloeodal; prothallus line dark brown, in contact with other lichens; photobiont trentepohlioid, the cells rounded to elliptical, 4–13 × 2–10 μm, in short chains or single cells; mycobiont hyphae 1.0–2.0 μm wide; calcium oxalate crystals not observed. ASCOMATA adnate, irregularly rounded to elliptical to weakly lobed, 0.15–0.3 × 0.1–0.3 mm, sometimes a few aggregated, with ± steep flanks; disc flat to weakly convex, purplish brown, ± white pruinose; margins level with the disc, with sparse orange-red pruina; proper exciple pale brown, 15–20 μm wide, of compacted and parallel paraphysoidal hyphae, with numerous pale, 1–4 μm large crystals in the outer parts; some hyphae extending from the exciple as short, dark brown, thick-walled, sparsely branched hairs; epithecium pale brown, 10–25 μm tall, conglutinated only in the lower portions; hymenium hyaline to pale reddish brown, 65–90 μm tall, strongly conglutinated, the asci closely spaced; hypothecium hyaline to pale reddish brown, 20–40 μm tall, strongly conglutinated, subparaplectenchymatic (cells 1–11 × 1–2(–3) μm); quinoid pigments sparse in proper exciple, epithecium and hypothecium, as clusters of ca 1–2 μm large orange red granules and as amorphous pigment in the hyphal walls and gelatinous matrix; paraphysoids branched and netted, 1.0–1.5 μm wide, loosely arranged, somewhat wavy; paraphysoid tips slightly widened to 2–3 μm, loosely intertwined, some projecting from the epithecium as short hairs, with brown pigmented walls. ASCI of the Arthonia-type, clavate, with broadly triangular ocular chamber, 65–90 × 20–28 μm (n=10), lateral walls ca 1 μm thick, base not abruptly deflected, 8-spored (spores in 2–3 irregular rows). ASCOSPORES narrow ovoid to slipper shaped with enlarged apical cell, (20.0–)21.8–26.0(–28.0) × (7.0–)7.7–9.1(–9.0) μm (n=12; l: mean=23.9, STD=2.10; w: mean=8.4, STD=0.67), 4–5-septate, pale brown to brown with smooth perispore. PYCNIDIA not observed.

Chemistry.— Pigments A1, A2 and A3 (all major) in solvents B′ and C detected by TLC. Thallus hyphae I–, KI–; ascomatal gels I dil + pale blue, I+ deep blue, KI+ deep blue; asci without KI+ blue ring structure in the tholus; ascospore walls and septa I–, KI–. The pigments dissolve in K with purple solution in which purple granules precipitate.

Ecology and distribution.— The limited data available on C. cinnabarinum in Japan indicate a south-western distribution from the Pacific coast of central Honshu to Ryuku and the Ogasawara (Bonin) Islands. All specimens were collected in the lowlands, from smooth bark of trunks and thin branches of broad-leaf evergreen and deciduous trees including Ficus spec.

Notes.— Coniocarpon cinnabarinum is a highly polymorphic species at the world level in terms of ascoma morphology and habitat ecology. It is separated from other Coniocarpon species by a combination of it’s rounded to lobate (not clearly lirellate) ascomata, 3–5-septate ascospores 19–31 × 5–10 μm, and the quinoid pigments A1–A3. Future revision may demonstrate that C. cinnabarinum represents a complex of closely related taxa. The specimens from Japan are quite homogeneous and fit well in the presently rather broad circumscription of the species. Molecular data of the mtSSU and nLSU gene loci ( Fig. 2 ) place Japanese specimens from the Ogasawara Islands as sister to C. cinnabarinum from Europe and eastern Africa. The genetic variation could indicate different species but in lack of clear discriminating morphological and chemical characters we refrain from taxonomic consequences here.

The aza-anthraquinones bostrycoidin and 8- O -methyl bostrycoidin together with the isofuranonaphthoquinones arthoniafurone A and B (minor novel yellow pigments) are reported for C. cinnabarinum from Japan ( Yamamoto et al. 2002; specimen not seen). No TLC data are given for these pigments in the cited literature.

Specimen examined.— Japan, Honshu. Prov. Tôtômi (Pref. Shizuoka): Saruwatari, Aikusa-mura, Ogasa-gun. 29. vii. 1932, Y. Asahina 64 (TNS). Ryuku Islands (Pref. Okinawa): Naha-city, Matsuyama-cho, 05. vii. 1922, s.coll., s.n. (TNS). Ogasawara Islands (Tôkyô Metropolis): Chichi-jima, along the road to Mt Mikazuki (27°05′23″N, 142°11′21″E), on large Ficus tree, elev. 146 m. 17. iii. 2013, A. Frisch 13/Jp127, 128 & Y. Ohmura (TNS); ibid., Y. Ohmura 9702 (TNS); ibid., Mt Yoake (27°04′58″N, 142°13′22.5″E), on branches of trees and shrubs at forest edge, elev. 300 m. 18. iii. 2013, A. Frisch 13/Jp226, 231, 232a & Y. Ohmura, H. Kashiwadani (TNS); ibid., Nagatani (27°03′43″N, 142°13′04″E), on tree in dense forest, elev. 146 m. 18. iii. 2013, A. Frisch 13/Jp71 & Y. Ohmura, H. Kashiwadani (TNS).

Figures

FIGURE 2. Best tree obtained from RAxML analysis showing the phylogenetic position of A. picea, A. sanguinaria and the Japanese specimens of Coniocarpon cinnabarinum (in bold and indicated by black bold supporting branches) in Arthoniaceae.Additional branches leading to taxa containing K+ reddish pigments are indicated in bold grey. Support values of the RAxML analysis (first) and Bayesian analysis (second) are indicated.

FIGURE 3. Thallus and ascomata. A. Arthonia lopingensis on Graphis handelii (Frisch 12/Jp5, TNS). B. Coniocarpon cinnabarinum (Frisch 13/Jp128, TNS). C, D. Arthonia sanguinaria (Frisch 13/Jp59, TNS): A margin of thallus, B ascomata. E. Arthonia picea (Kashiwadani 14142, TNS). F. Arthonia eos (Thor 26000, GZU). Scale bars:A, B=0.5 mm, C, E, F=1 mm, D=1.5 mm.