New and interesting species in the family <i>Graphidaceae</i> (Ascomycota: <i>Ostropales</i>) from Vietnam

다국어 초록 (Multilingual Abstract)

<B>Abstract</B><P>The lowland area of southern Vietnam contains a high diversity of corticolous, crustose lichens, particularly in the family <I>Graphidaceae</I>. Two species, <I>Acanthothecis verrucosa</I> S. Joshi, Upreti & Hur and <I>Graphis exuta</I> S. Joshi, Upreti & Hur, are described new to science. <I>Acanthothecis verrucosa</I> is characterized by a verrucose, olive green thallus containing irregular to shortly lirellate apothecia, hyaline to brownish proper exciple apically lined by robust periphysoids, muriform ascospores, 30-70 × 15-20 μm, and the presence of psoromic and subpsoromic acids. <I>Graphis exuta</I> is characterized by a smooth, greenish white thallus, simple lirellae lacking thalline margin, entire labia coarsely white pruinose towards slit, muriform ascospores, 20-35×10-13 μm, and norstictic acid in the thallus. A new name, <I>Acanthothecis yokdonensis</I> S. Joshi & Hur, is proposed here for the species <I>Acanthothecis salazinica</I> S. Joshi & Hur, a later homonym of <I>A. salazinica</I> van den Boom & Sipman. In addition, 34 species from Vietnam are newly reported. A world key to the group of <I>Graphis</I> species characterized by short, simple and sessile lirellae lacking or with basal thalline margins (<I>nuda</I>-morph) is presented.</P>