Mangoldia 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 : 2

Mangoldia Lücking, Parnmen & Lumbsch , gen. nov. ( Fig. 1 ) MycoBank No.: MB801428

A new genus in the family Graphidaceae , subfamily Graphidoidae , tribe Graphideae , characterized by a white, ecorticate thallus, ascomata with exposed disc and thin, split thalline margins, a non-inspersed hymenium, and distoseptate, hyaline, I+ violet-blue ascospores.

Type species: — Mangoldia australiana Lücking, Parnmen & Lumbsch.

Thallus corticolous, continuous, in part endoperidermal; surface uneven, white; in section with indistinct, very thin, corticiform layer and irregular algal layer. Apothecia erumpent, angular to lirelliform; disc exposed, blackish brown to black, epruinose; thalline margin thin, white, fissured to lobulated; proper margin thin, prominent, black, in section very thin, prosoplectenchymatous, pale yellowish to brownish in outer parts; periphysoids absent. Hymenium not inspersed; paraphyses unbranched. Ascospores 4–8 per ascus, muriform, ellipsoid, with thickened, I+ violet-blue septa and rounded lumina, colourless. Secondary chemistry: no substances detected by TLC.

Etymology: —This new genus is dedicated to Armin Mangold (Berlin) for his outstanding contribution to the knowledge of thelotremoid Graphidaceae in Australia.

Notes: —The new genus superficially resembles species of Phaeographis , such as P. dendritica (Ach.) Müll. Arg. ( Müller, 1882: 382) or P. lecanographa (Nyl.) Staiger (2002: 334) , in having ascomata with an exposed, dark brown disc and thin, thalline, partially split apothecial margins. However, the ascospores are of the Graphis type, being hyaline and I+ violet-blue. This situation is similar to that found in the recently described genus Halegrapha , which combines a Graphis - type morphology with a Phaeographis - type hymenium and ascospores ( Lücking et al. 2011). DNA sequence data of the nuclear LSU rDNA support the distinction of the new genus as discussed elsewhere ( Rivas Plata et al. 2012b).

There is a certain resemblance with species of Thalloloma Trevisan (1853: 13) , which share the Graphis - type ascospores, but their ascomata are usually larger and pruinose, with the disc having a light to chocolatebrown or dark red color ( Staiger 2002). One species of Thalloloma from Australia, T. atronitens (A. W. Archer) A.W. Archer (2005: 77) is, however, very similar to the new taxon in having a dark, non-pruinose disc and muriform ascospores, but its ascomata are lirelliform with distinct labia and entire thalline margins, and its ascospores are larger ( Archer 2009). This species is congeneric with the type species of Mangoldia and hence the new combination, M. atronitens , is proposed below.

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.