Jocatoa R.Miranda, gen. nov. Fig. 4
Index Fungorum number: MB 834677; Facesoffungi number: FoF 13846
A new genus in the family Graphidaceae, subfamily Graphidoideae, tribe Graphideae, differing from Diorygma in that the paraphysis tips are simple, thin and do not form an epithecium. Thallus ecorticate; ascocarps solitary to pseudostromatic; excipulum not carbonized; spores muriform, Iþ strongly violet; chemistry of the stictic acid complex.
Type species: Jocatoa agminalis (Nyl.) Lu¨cking, Herrera-Camp. & R.Miranda.
Etymology: The genus is named in honour of the late Prof. Jose´ Castillo Tovar (1935–2012), for educating the current generation of Mexican mycologists and for introducing the first author to the study of lichens.
Remarks: The new monospecific genus strongly resembles species of Diorygma in the ecorticate thallus, spore type, chemistry, and in the laterally branched and anastomosed paraphyses that are embedded in a thick gelatinous matrix. Nonetheless, in Diorygma the paraphysis tips are reticulately branched, anastomosed and thickened, which form a clear epithecium (Kalb et al. 2004), while in the new genus the paraphyses tips are simple, thin and do not form an epithecium. The genus Glyphis differs by having a heavily carbonized exciple with dark brown paraphysis tips intermingled with brown granules.
The younger names of genera that are synonyms with Diorygma (Type Diorygma hieroglyphicum) are: Solenographa (Type Diorygma confluens), Glaucina- ria (Type Diorygma poitaei), and Cyclographina (Type Diorygma pruinosum). Of these, D. poitaei and D. pruinosum cluster in a monophyletic group with D. hieroglyphicum. Diorygma confluens has not been sequenced yet, but it differs from the new genus in the carbonized exciple and in the presence of the epithecium. As the genus Jocatoa is outside the Diorygma clade (Fig. 1), none of those names are available.
The type species of Jocatoa was previously included in Medusulina, a polyphyletic genus no longer recognized and loosely characterized by having aggregate lirellae, carbonized excipulum and muriform ascospores (Lu¨cking 2013; Zahlbruckner 1926). However, the name is no longer available because its type species, Medusulina nitida, belongs to Fissurina (Staiger 2002). Medusulina was previously believed to be the hyaline ascospore counterpart of Sarcographa (Mu¨ller 1894) or close to Glyphis but with muriform ascospores (Zahlbruck- ner 1926). Besides Fissurina and the new genus Jocatoa, another species previously described in Medusulina is now a member of Redonographa (Lu¨cking et al. 2013). None of these genera is particularly close to Sarcographa or Glyphis, although these last two genera and Jocatoa belong to the same tribe, Graphideae.
Figure 1. Phylogeny of the family Graphidaceae based on a Maximum Likelihood analysis of the markers mtSSU, nuLSU and RPB2. Support values are shown as numbers if Maximum Likelihood bootstrap values ≥70 and as bold branches if Bayesian posterior probabilities ≥0.95. Bold names show new sequences from this study. For collapsed branches refer to Supplementary Figure S1.
Figure 4. Jocatoa agminalis. A–D. Habit showing lirellae. E. Section of lirella showing anastomosed paraphyses towards the exciple. F. Section of lirella showing tips of paraphyses in KOH. G. Muriform ascospore. H. Section of lirellae showing uncarbonized excipulum (appearing black due to presence of abundant crystals that dissolve in KOH). Scale: A–D 1 mm; E–G 40 lm; H 100 lm. Specimens: A A. Lindig 143 (isotype of Graphis agminalis, G); B J. W. Eckfeldt 56A (holotype of Medusulina texana); C, F R. Miranda-Gonza´lez 2040; D R. Miranda-Gonza´lez 5005; E, G, H R. Miranda-Gonza´lez 5004.