Pyrenula celaticarpa 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 : 201-202

Pyrenula celaticarpa Aptroot & M. Cáceres , sp. nov. ( Fig. 4A–C )

Mycobank #811020

Pyrenula with deeply immersed ascomata with red ostioles, ascospores 3-septate, 21–24 × 10–11 μm.

Holotype: — BRAZIL. Sergipe: Areia Branca, Parque Nacional Serra de Itabaiana ; 10˚45’37”S, 37˚22’15”W; alt. c. 250 m; on bark of tree; 18 September 2013, M.E.S. Cáceres & A. Aptroot 18593 ( ISE; isotype: ABL).

Thallus rather thick (0.1–0.2 mm thick), corticate, olive green, minutely cracked throughout, without pseudocyphellae, without prothallus. Ascomata 1–2 mm deep immersed in the bark underneath the thallus, pyriform, 0.6–0.9 mm diam., single. Wall carbonized all around. Ostiole apical, usually red brown to red, rarely pale brown or almost black, flush to distinctly convex. Hamathecium inspersed with hyaline oil droplets. Ascospores 8/ascus, irregularly biseriate, dark brown, 3-septate, 21–24 × 10–11 μm, lumina diamond-shaped, separated from the wall by a thick layer of endospore, ends pointed, often slightly constricted at the septa. Pycnidia not observed. Chemistry: Ostiole K+ crimson, with unidentified anthraquinone (too little for TLC); thallus UV –, K+ orange brown, possibly due to traces of the same anthraquinone.

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

Discussion: —This species is characterized by deeply immersed ascomata which are only visible by the ostioles, which are bronw and convex when well developed. The orange brown reaction of the thallus is also unusual, although positive K-reactions are present in more species, especially anthrquinone-containing species of the group around the type species, Pyrenula nitida (Weigel) Ach. ( Acharius 1814: 125). There are so far only two other Pyrenula species described with ostioles that contain anthraquinones, viz. P. rubrostoma R.C. Harris ( Tucker & Harris 1980: 16) and P. rubrostigma Aptroot & M. Cáceres ( Aptroot et al. 2013: 190); both species have superficial, conical ascomata. Pyrenula celaticarpa is closest to an undescribed species collected in Puerto Rico, which mainly differs by the absence of inspersion and somewhat larger ascospores.

Figures

FIGURE. 4. Pyrenula celaticarpa (isotype ABL); A, habitus showing convex, dark red to almost black ostioles; B–C, ascospores; D–E, P. inspersicollaris (isotype ABL); D, ascospore; E, habitus showing a raised shared ostiole surrounded by immersed ascomata;. A, E: bar = 0.5 mm; B: bar = 10 μm; C–D: bar = 5 μm.