Jocatoa agminalis (Nyl.) Lu¨cking, Herrera-Camp. & R.Miranda, comb. nov. Fig. 4
MycoBank number: MB 834678; Index Fungorum number: IF 834678; Facesoffungi number: FoF 13845;
” Graphis agminalis Nyl., Ann. Sci. Nat., Bot., Sér. 5 7: 334 (1867); ” Graphina agminalis (Nyl.) Zahlbr., Cat. Lich. Univers. 2: 394 (1923); TYPE: COLOMBIA. Near Magdalena River, elev. 100 m, on bark, 1863, A. Lindig 143 (holotype: H- NYL 7602!; isotypes: BM!, G!, M!). ¼ Medusulina texana Müll. Arg., Bull. Herb. Boissier 2: 93 (1894); TYPE: U.S.A. TEXAS: Brownsville, on bark, 1881, J.W. Eckfeldt 56A (holotype: G!).
Description. Thallus crustose, corticolous, epiperidermal, ecorticate, light yellowish brown to olive-green, sometimes not continuous and then with endoperidermal parts but always well developed near the ascocarps, UV–, with a black prothallus present at contact lines with other lichens. Photobiont trentepohlioid, in a continuous layer surrounded by small crystals that appear beige in polarized light and that dissolve in KOH, as well as insoluble coarse crystals. Ascocarps abundant, lirelliform to rounded, erumpent, straight to curved, unbranched when young to stellate or in groups forming white to cream-colored pseudostromata, individual lirellae 0.2–1.5 × 0.2–0.25 mm, in groups up to 1 cm long; thalline margin lateral, raised above disc, concolorous with the thallus; disc black to brown black, sometimes with remnants of thallus that give the impression of coarse pruina, immersed, exposed when mature but sometimes partly covered by the thalline margin. Exciple not striate, hyaline to light brown, with small crystals and a granular appearance POL that originates from the thallus margin, 22–30 lm wide; hypothecium hyaline 30–50 lm deep; hymenium hyaline, not inspersed with oil droplets, embedded in a strong gelatinous matrix, 175–250 lm high, I–, epihymenium golden brown, with a granulose appearance; paraphyses simple to anastomosed specially towards the exciple, tips simple and not swollen, periphysoids absent. Epithecium absent. Ascospores 1 per ascus, hyaline, strongly muriform, ellipsoid, inner cells larger than peripheral cells, (110–)150–192(–217) × (45–)50– 70(–85) lm, I strongly violet, frequently with a hyaline gelatinous perispore.
Chemistry. Hypostictic, stictic, cryptostictic, and constictic acids, plus three unknown substances with Rf 5–6 (solvent A) and Rf 5 (solvent C) that react UVþ red and white on TLC plates before the acidþheat treatment.
Ecology and distribution. In the study area this species is mostly found in the mature tropical dry forests of the Chamela-Cuixmala Biosphere Reserve, but one depauperate sample (R. Miranda-Gonza´lez 3080) was found in a secondary forest in an area surrounding the Reserve. It is a rare species in the study area, found on the main trunk of the phorophytes Apoplanesia paniculata, Cordia alliodora, Thouinia paucidentata, and in the canopy of Amphipterygium adstringens. The species was previ- ously known from the type locality of Graphis agminalis in Colombia, a low altitude interandine dry valley along the Magdalena River, and from the type locality of Medusulina texana in Brownsville, Texas (Müller 1984). Further collections (not seen by us) are registered in the Consortium of North American Lichen Herbaria (CNALH) from Louisiana (USA) and Tamaulipas (Mexico) (Accessed through Consortium of North American Lichen Herbaria (CNALH) Data Portal, http//:lichenporta- l.org/portal/index.php, 2018-07-16). Thus, through- out its range, J. agminalis appears to be a corticolous species associated with dry forest and semi-arid areas.
Remarks. Jocatoa agminalis is overall similar to Diorygma monophorum (Nyl.) Kalb, Staiger & Elix, which has smaller ascospores (105–165 × 35–60 lm), anastomosing paraphysis tips, lacks stictic acid, and does not have aggregate ascocarps. Notably, D. monophorum was described as having a slightly different nature of the paraphyses, as hardly anastomosing, thinner towards the tips and forming a mostly distinctly developed epithecium (Kalb et al. 2004), which might be explained by the observation that in many species of Diorygma, only the paraphyses lateral to the excipulum show distinct anastomoses. The original description of Medusulina texana by Müller (1894) and subsequently the treatment by Fink (1935) mention soredia for this taxon; however, neither the type collection nor our samples have soredia, so this possibly referred to the crumbling remnants of the thallus margins of the ascomata.
Additional specimens examined. MEXICO. JALISCO: La Huerta Mun., Chamela-Cuixmala Biosphere Reserve, Estación de Biología Chamela, on Tejón trail, elev. 57 m, on bark of Apoplanesia paniculata, Jun. 2009, R. Miranda-González 1451, 2040, on bark of Thouinia paucidentata, May 2015, R. Miranda-González 5004, on bark of Apoplanesia paucidentata, Jun. 2015, R. Miranda-González 5005, on bark of fallen branch from canopy of unknown tree, Dec. 2015, R. Miranda-González 4745; ibid.; on Eje Central road 430 m, elev. 62 m, on bark of fallen branches from the canopy of Amphipterygium adstringens, Dec. 2015, R. Miranda-González 4744; ibid.; Surrounding areas of the Chamela-Cuixmala Biosphere Reserve, Ejido Caimán, elev. 72 m, on bark of Cordia alliodora, Sep. 2010, R. Miranda-González 3080. (all specimens in MEXU).
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-González 2040; D R. Miranda-González 5005; E, G, H R. Miranda-González 5004.