Introduction
In Aracaju, the capital of Sergipe State in north-eastern Brazil, the only patch of Atlantic forest in an intermediate stage of regeneration is the Área de Proteção Ambiental (APA) Morro do Urubu, with c. 214 hectares. It is an area of environmental protection delimited to the north by the Sal River and to the east by the Sergipe River, and surrounded to the south and west by urban areas of the northern part of the city (Matos & Gomes Reference Matos and Gomes2011).
The APA Morro do Urubu was originally dominated by the Atlantic forest which is now much reduced, with only a very small patch of the forest remaining. It is considered the only urban Mata Atlântica remnant in Aracaju, with mesophytic deciduous and semi-deciduous forest, and cerrado enclaves in isolated points (Souza Reference Souza, Araújo, Vilar, Wanderley and Souza2006). Part of the APA also houses the State Park José Rollemberg Leite, and a Zoo, also known as the City Park (Parque da Cidade) (Souza Reference Souza, Araújo, Vilar, Wanderley and Souza2006; Matos & Gomes Reference Matos and Gomes2011).
The lichen flora of NE Brazil is still incompletely known, despite the pioneering work by Cáceres (Reference Cáceres2007). During a floristic lichen survey of the APA Morro do Urubu under guidance of the first author, undescribed species of Byssoloma and Porina were found. They are described below.
The genus Byssoloma comprises c. 40 species worldwide (Lücking Reference Lücking2008). The present those differs from all species known so far in the genus by the combination of the following characters: apothecia dark grey, margin white, byssoid, and ascospores consistently 1-septate. The genus Porina comprises c. 250 species worldwide (Lücking Reference Lücking2008). The present species differs from all those known so far in the genus by the combination of the following characters: thallus with isidia, black perithecia, and relatively large, 3-septate ascospores.
Material and Methods
Identification and descriptive work were carried out in Itabaiana, Universidade Federal de Sergipe, using a Leica EZ4 stereomicroscope and a Leica DM500 compound microscope, and also in Soest using an Olympus SZX7 stereomicroscope and an Olympus BX50 compound microscope with interference contrast, connected to a Nikon Coolpix digital camera. Sections were mounted in tap water, in which all measurements were also taken. The specimens from this study are preserved in ISE. The chemistry was investigated by performing thin-layer chromatography (TLC) using solvent A (Orange et al. Reference Orange, James and White2001).
The Species
Byssoloma catillariosporum M. Cáceres, M. W. O. Santos & Aptroot sp. nov.
MycoBank No.: MB 802581
Byssoloma with dark grey apothecia, margin white, byssoid, and ascospores consistently 1-septate, 9–11×3·5–4·0 µm.
Type: Brazil, Sergipe, Aracaju, APA Morro do Urubu (Parque da Cidade), on bark of tree, c. 10 m alt., 12 August 2011, M. E. S. Cáceres & M. W. O. Santos 13697 (ISE—holotype).
(Fig. 1)
Byssoloma catillariosporum (holotype). A & B, habitus; C, section through ascoma; D, hyphae of apothecium margin; E, ascospores. Scales: A & B=1 mm; C=50 µm; D=10 µm; E=3 µm. In colour online.
Thallus thin, not corticate, dull, starting as isolated granules of c. 50 µm, soon aggregating to form a nearly continuous pale greenish grey crust on a thin whitish byssoid hypothallus, greenish grey. Algae green, c. 7 µm diam.
Apothecia appressed, 0·2–0·5 mm diam.; disc flat, dull, brownish grey, not pruinose, margin whitish to chamois-coloured, dull, felty, c. 0·05 mm wide. Hymenium hyaline, but greenish at the bottom by the diluted pigment of the hypothecium, KOH−, IKI+ blue; paraphyses branched; hypothecium black due to high concentration of a greenish pigment, KOH; excipulum hyaline, with anastomosing hyphae of c. 3 µm wide. Ascospores 8 per ascus, hyaline, ellipsoid, 1-septate, 9–11×3·5–4·0 µm.
Pycnidia not observed.
Chemistry
Thallus UV−, C−, K−, KC−, P−. No substances detected with TLC.
Ecology and distribution
On smooth bark of trees in forest remnant. Known only from Brazil.
Discussion
This is one of the relatively few corticolous species in the genus. It is reminiscent of B. leucoblepharum (Nyl.) Vain. in thallus and especially in apothecium colour (Lücking Reference Lücking2008) but differs, for example, by the consistently 1-septate ascospores. Five species of Byssoloma with 1-septate ascospores are keyed out in Lücking (Reference Lücking2008), but all differ at least in apothecium colour, a character mentioned in the key for all species. The ascospores remain 1-septate throughout their development.
Porina isidioambigua M. Cáceres, M. W. O. Santos & Aptroot sp. nov.
MycoBank No.: MB 802582
Porina with thallus with isidia, black perithecia, and 3-septate ascospores of 32–37×6–8 µm.
Type: Brazil, Sergipe, Aracaju, APA Morro do Urubu (Parque da Cidade), on bark of tree, c. 10 m alt., 12 August 2011, M. E. S. Cáceres & M. W. O. Santos 13698 (ISE—holotype).
(Fig. 2)
Porina isidioambigua (holotype). A & B, habitus; C, isidia; D, isidia at margin of bark flake; E, squash preparation of an isidium with single algal cells inside and cortex outside and one accidental Pyrenula ascospore attached; F, section through ascoma; G & H, ascospores. Scales: A & B=1 mm; C & D=0·1 mm; E=10 µm; F=50 µm; G & H=5 µm. In colour online.
Thallus corticate, smooth, continuous, thin, olive green, with dispersed but locally, especially at the margins of bark flakes, numerous simple cylindrical or gnarled corticate isidia of c. 50 µm high and c. 20 µm thick; algae trentepohlioid, cells single.
Ascomata perithecioid, simple, dispersed, globose, emergent, 0·2–0·3 mm diam., black, edges with thallus covering. Wall carbonized, thick above and in the upper half, very thin in the lower half, somewhat extending sideways as an involucrellum, without crystals, KOH−, c. 50 µm thick. Ostioles black, KOH−, apical. Hamathecium hyaline, not inspersed. Asci cylindrico-clavate, IKI−, with 8 ascospores. Ascospores hyaline, IKI−, 3-septate, fusiform, 32–37×6–8 µm, ends pointed.
Pycnidia not observed.
Chemistry
Thallus UV−, C−, K−, KC−, P−. No substances detected with TLC.
Ecology and distribution
On smooth bark of trees in forest remnant. Known only from Brazil. The species grows together with Pyrenula cubana (Müll. Arg.) R. C. Harris.
Discussion
This seems to be close to Porina ambigua Malme, from which it differs mainly by the presence of tiny isidia and the larger ascospores. Isidiate species are rare in the genus, even if taken in a wide sense, as is done here. The species belongs to Trichothelium in the sense of Harris (Reference Harris1995), Pseudosagedia in the sense of Hafellner & Kalb (Reference Hafellner and Kalb1995) and Zamenhofia in the sense of Clauzade & Roux (Reference Clauzade and Roux1985). The species differs also when sterile from all known isidiate species in Porina in the wide sense. Trichothelium isidiatum R. C. Harris (Harris Reference Harris1995) differs by the much more numerous and larger isidia. Porina (or Zamenhofia) rosei Sérus. (Smith et al. Reference Smith, Aptroot, Coppins, Fletcher, Gilbert, James and Wolseley2009) has somewhat similar isidia that, however, become branched, larger and heaped. Porina (or Zamenhofia) hibernica P. James has much larger, non-corticate isidia (Smith et al. Reference Smith, Aptroot, Coppins, Fletcher, Gilbert, James and Wolseley2009). Porina conspersa Malme and P. distans Vězda & Vivant can have somewhat similar isidia, but have the algal cells in plates or threads (Lücking Reference Lücking2008), not single as in the new species.
The CNPq – Conselho Nacional de Desenvolvimento Científico e Tecnológico (Processo 501633/2009-0) is thanked for a research grant to MESC and a student research scholarship to DAM. MWOS thanks the Universidade Federal de Sergipe for a student research scholarship. Leo Spier is thanked for performing thin-layer chromatography. AA is grateful to the Stichting Hugo de Vries-fonds for a travel grant.
