Mangoldia australiana Lücking, Parnmen & Lumbsch, 2012

Lücking, Robert, Parnmen, Sittiporn & Lumbsch, Thorsten, 2012, Mangoldia, a new lichen genus in the family Graphidaceae (Ascomycota: Ostropales), Phytotaxa 69 (1), pp. 1-5 : 3-4

Mangoldia australiana Lücking, Parnmen & Lumbsch , sp. nov. ( Fig. 1 ) MycoBank No.: 801429

Characterized by small, white thalli and small ascomata (up to 0.25 mm diam.), which are irregularly angular to elongate in shape with a blackish brown disc and white, split thalline margin; ascospores muriform, of the Graphis - type, hyaline, I+ violet-blue.

Type:— AUSTRALIA. New South Wales: Mungo Brush Camping Area, Myall Lakes National Park ; A. Mangold 27zB (holotype CANB!, isotype F!) .

Thallus corticolous, up to 2 cm diameter, 40–60 µm thick, continuous, in part endoperidermal; surface uneven, white; in section with indistinct, very thin, corticiform layer and irregular algal layer. Apothecia erumpent, angular to slightly elongate, 0.15–0.25 mm diam. or up to 0.5 mm long; disc exposed, blackish brown to black, epruinose; thalline margin thin, white, fissured to lobulated; proper margin thin, prominent, black, in section very thin, prosoplectenchymatous, 20–30 µm thick, pale yellowish to brownish in outer parts; periphysoids absent. Hymenium 100–120 µm high, not inspersed; paraphyses unbranched. Ascospores 4–8 per ascus, muriform with (5–)7(–9) transverse and 1–3 longitudinal septa per segment, 25–35 × 8–12 µm, ellipsoid, with thickened septa and rounded lumina, colourless, the septa I+ violet-blue. Secondary chemistry: no substances detected by TLC.

Distribution and habitat: —So far the new species and genus is only known from the type locality in New South Wales ( Australia).

Notes: — Mangoldia australiana resembles a diminutive Phaeographis lecanographa due to its angular ascomata with split thalline margins, but can immediately be separated by the not inspersed hymenium and colorless, I+ violet-blue ascospores of the Graphis type. Mangoldia atronitens (see below) has distinctly lirellate, longer ascomata with more or less entire margins and larger ascospores.

Figures

FIGURE 1.Mangoldia australiana (holotype). A–B, thallus with ascomata. C, section through ascoma showing hymenium with asci and ascospores and lateral excipulum. D, asci with young (left) and mature (right) ascospores. E, two mature ascospores. F, ascus with mature ascospores staining violet-blue in Iodine solution. Scale in A and B = 1 mm, in C–F = 10 µm.