Pyrenula aurantiacorubra 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 : 201

Pyrenula aurantiacorubra Aptroot & M. Cáceres , sp. nov. ( Fig. 3A–C )

Mycobank #811019

Pyrenula with orange red thallus, ascospores muriform, 3(–5) × 1–2-septate, 9–18 × 5–10 μm.

Holotype: — BRAZIL. Sergipe: Ribeirópolis, Serra do Machado ; 10˚33’S, 37˚22’W; alt. c. 250 m; on bark of tree; 9 May 2014, M.E.S. Cáceres & A. Aptroot 21677 ( ISE; isotype: ABL).

Thallus thin, somewhat granular, orange red mottled with some grey, without pseudocyphellae, without prothallus. Ascomata superficial, globose, 0.2–0.35 mm diam., single, distinctly brown, generally with orange with red pruina. Wall barely carbonized. Ostiole apical, black. Hamathecium not inspersed. Ascospores 8/ascus, brown, irregularly biseriate, muriform, 3(–5) × 1–2-septate, 9–18 × 5–10 μm, lumina mostly rounded. Pycnidia not observed. Chemistry: Pigment K+ deep crimson, UV + orange. TLC revealed several anthraquinones including 7-chloroemodin as major compound, and one or more derivatives of it as minor compounds; the lower part of the TLC plate is streaked with purple until as high as Rf 4.

Ecology and distribution: —On smooth bark in disturbed Atlantic rain forest. So far only known from Brazil.

Discussion: —This species is internally very similar to Pyrenula ochraceoflava (Nyl.) R.C. Harris (1989: 96) . For instance, it also shows a large variation in ascospore size, even within one ascus. However, its thallus is spectacularly red orange, and it was already recognized in the field (fig. 3A) as a species new to science, which is no often possible. Pyrenula ochraceoflava grows at the same location (collecting numbers 2149 & 21654), and clearly differs by the yellow orange thallus. These two species were co-chromatographed and P. ochraceoflava contains only 7-chloroemodin as major compound, and one or more derivatives of it as minor compounds; no further anthraquinones. The purple streak is never formed on the TLC plate.

Figures

FIGURE 3 Pyrenula aurantiacorubra; A, field picture of a tree covered with the species in the field; B, ascospores showing the variation in size even within a single ascus (isotypeABL); C, habitus showing brown, raised ascomata (isotype ABL); D–F, P.cinnabarina (isotypeABL); D, twig