Resolving the genus Phaeographina Müll . Arg . in China

As part of ongoing studies of the lichen family Graphidaceae in China, the status of all taxa traditionally assigned to the genus Phaeographina reported from China is resolved in the present paper. Five new combinations are proposed: Phaeographis pleiospora (Zahlbr.) Z.F. Jia & Lücking, comb. nov., Platygramme elaeoplaca (Zahlbr.) Z.F. Jia & Lücking, comb. nov., Platythecium maximum (Groenh.) Z.F. Jia & Lücking, comb. nov., P. pyrrhochroa (Mont. & Bosch) Z.F. Jia & Lücking, comb. nov., and Sarcographina heterospora (Nyl.) Z.F. Jia & Lücking, comb. nov. Six new synonyms are established: Phaeographina callospora Zahlbr. [= Diorygma hieroglyphicum (Pers.) Staiger & Kalb], P. fukiensis Zahlbr. [= Pallidogramme chrysenteron (Mont.) Staiger, Kalb & Lücking], P. fukiensis var. substriata Zahlbr. [= Pallidogramme chrysenteron (Mont.) Staiger, Kalb & Lücking], P. granulans Zahlbr. [= Platygramme platyloma (Müll. Arg.) M. Nakan. & Kashiw.], P. pluvisilvarum Zahlbr. [= Graphis alpestris (Zahlbr.) Staiger], and P. valida Zahlbr. [= Thecographa prosiliens (Mont. & Bosch) A. Massal.]. Two additional synonyms are reported: Phaeographina subrigida (Nyl.) Zahlbr. is synonymized under Platygramme platyloma (Müll. Arg.) M. Nakan. & Kashiw., and Platythecium dimorphodes (Nyl.) Staiger under Platythecium pyrrhochroum (Mont. & Bosch) Z.F. Jia & Lücking.


Materials and methods
Type specimens and other material investigated for this study are deposited in BRSL, H, HMAS-L, KUN, LCU-L, PC, TNS, UPS, and W. For several of the names included here that have already been treated by Kalb et al. (2004), Staiger (2002), and Lücking et al. (2009), we do not provide full synonymies and type specimen citations but give the corresponding reference.A dissecting microscope (Olympus SZX12) and a light microscope (Olympus BX51 and Nikon Eclipse-55i) were used for the morphological and anatomical studies.Measurements were taken from manual cross sections of fruit bodies in water.Amyloidity of the ascospores was tested using Lugol's solution.
In cases where the chemistry of the type material had not been studied previously, lichen substances were identified by thin-layer chromatography (Culberson and Kristinsson 1970;Culberson and Kristinsson 1972;White and James 1985).

Taxonomy
Annotated checklist of Chinese species previously reported under the name Phaeographina Müll.Arg.
Based on the Diorygma-like thallus and ascomata, this taxon belongs in Diorygma.
It has a clear hymenium, single-spored asci, hyaline, muriform ascospores 90-100 × 29-32 µm (Zahlbruckner 1933), and stictic acid.These characters, as well as the immersed lirellae with a split between excipulum and thalline margin, agree with D. hieroglyphicum (Pers.)Staiger & Kalb and hence, we propose this name as a synonym of the latter.The ascospores in this material are partially old and become brownish, which is the reason why it was described in Phaeographina.Phaeographina callospora Zahlbr.
Following Lücking et al. (2008), this taxon was transferred to the genus Pallidogramme.
Due to the characteristics of thallus and ascomata, this taxon belongs in Pallidogramme.
According to the original description and excellent illustrations, this is a species of Platythecium, agreeing with P. serpentinellum (Nyl.)Staiger in the brown ascospores and with P. allosporellum (Nyl.)Staiger in the carbonized hypothecium.Groenhart (1958) beautifully illustrates the enormous extension of the thallus of the specimen in the field, with over 100 cm covering a large boulder.This is consistent with our observations that Platythecium species often form large thalli on rocks near streams.Since the type material is different from any known in the genus, it is here recombined as separate species, Platythecium maximum (Groenh.)Z.F.Jia & Lücking.It is a saxicolous species, within China reported from Hong Kong (Thrower 1988).

Phaeographina valida
Notes.This species is very similar to Sarcographina cyclospora Müll.Arg., but the latter differs in having a brownish to apically carbonized excipulum.