Pyrenula rubrolateralis Aptroot & M. Cáceres, 2015

Aptroot, André, Andrade, Dannyelly Santos, Mendonça, Cléverton, Lima, Edvaneide Leandro De & Cáceres, Marcela Eugenia Da Silva, 2015, Ten new species of corticolous pyrenocarpous lichens from NE Brazil, Phytotaxa 197 (3), pp. 197-206 : 205

Pyrenula rubrolateralis Aptroot & M. Cáceres , sp. nov. ( Fig. 5C–D )

Mycobank #811024

Pyrenula with eccentric red ostioles, ascospores 3-septate, 20–24 × 8–10 μm.

Holotype: — BRAZIL. Sergipe: Santa Luzia do Itanhy, Mata do Crasto ; 11˚22’S, 37˚25’W; alt. c. 10 m; on bark of tree; 26 March 2014, M.E.S. Cáceres & A. Aptroot 18783 ( ISE; isotype: ABL).

Thallus rather thin (up to 0.1 mm thick), rather irregular in thickness, corticate, olive green, closely following the cracks and fissures in the bark, without pseudocyphellae, surrounded by a c. 1 mm wide black prothallus line. Ascomata immersed in raised areas of the bark, almost completely covered by the thallus, pyriform, 0.6–0.9 mm diam., single. Wall carbonized all around. Ostiole eccentric, red brown to bright red, flush to distinctly convex. Hamathecium not inspersed with oil droplets. Ascospores 8/ascus, irregularly biseriate, brown, 3-septate, 20–24 × 8–10 μm, lumina mostly rounded to somewhat diamond-shaped, separated from the wall by a thick layer of endospore, ends pointed. Pycnidia not observed. Chemistry: Ostiole K–; thallus UV –; no substances detected with TLC.

Ecology and distribution: —On smooth bark in undisturbed Atlantic rain forest. Only known from Brazil.

Discussion: —This species is characterized by the eccentric red ostioles. It would key out in couplet 31 in key B in the world key (Aptroot 2012: 20). The closest species is the North American Pyrenula wetmorei R.C. Harris (1990: 69) , which differs by the inspersed hamathecium and the Pyrgillus -like ascospores with black pigment bands obscuring the septa.

Figures

FIGURE 5. Pyrenula musaespora (isotype ABL); A, habitus showing black ascomata emerging from ochraceous thallus; B, ascospore; C–D, P. rubrolateralis (isotype ABL); C, habitus showing a red ostiole; D, ascospores; E–F, Thelenella lateralis (isotype ABL); E, habitus