Arthoniaceae

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

Key to Arthoniaceae with reddish, K+ purple ascomata in Japan

1 Ascomata distinctly convex, adnate; disc covered by a bright red pruina; spores 1-septate, not brownish with age; unidentified quinoid pigments; Hokkaido, on bark of old Picea sp ............................................... Coniarthonia eos ( Frisch et al. 2014; Fig. 3F )

1′ Ascomata not convex, often lobed to lirellate; orange to red pruina concentrated along the ascomatal margin or an amorphous dark red pigmentation in the ascomata present; ascospores> 1-septate....................................................................................................2

2 Parasitic on Graphis spp. at least when young; apothecia lirellate, in stellate clusters; parietin and ± psoromic acid........................ ............................................................................................................................................................................ Arthonia lopingensis

2′ Not parasitic on Graphis spp. ; parietin absent...................................................................................................................................3

3 Ascomata covered by red to orange-red pruina at least along the margins; ascospores 4–5-septate with enlarged apical cell, 22–28 × 7–9 μm, brown with age; pigments A1, A2, A3................................................................................... Coniocarpon cinnabarinum

3′ Ascomata lacking red to orange-red pruina; pigment amorphous in the hymenial gels....................................................................4

4 Ascospores 26–35 × 9–12 μm, hyaline but brown with granular ornamentation in the perispore at late maturity; pigments A4, A5, A6 solvable in K but not in LCB.................................................................................................................................. Arthonia picea

4′ Ascospores 15–21 × 5–7 μm, hyaline; pigments A7 not solvable in K, but solving in LCB by forming clusters of needle-like, prismatic crystals; confluentic and ± psoromic acids........................................................................................ Arthonia sanguinaria

Figures

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.