Introduction
The genus Tapellaria is characterized by mostly black, lecideine apothecia with a dark brown, K+ purplish hypothecium, branched and anastomosing paraphyses and campylidia producing filiform conidia, present in numerous species of the genus. It is a predominantly foliicolous genus with only a small number of species growing on bark (Kalb & Vězda Reference Kalb and Vězda1987; Kalb & Hafellner Reference Kalb and Hafellner1992) or on rock (Vězda & Poelt Reference Vězda and Poelt1988). The genus was introduced by Müller Argoviensis (Reference Müller Argoviensis1890) for the single species T. herpetospora, now a synonym of T. moelleri. Two additional names in Tapellaria, based on material collected during research expeditions in New Guinea and Samoa, were described by Rechinger (Reference Rechinger1905 a,Reference Rechinger b ), namely T. gilva and T. samoana which are, however, synonyms of species in the unrelated genus Echinoplaca (Gomphillaceae), Echinoplaca pellicula and E. diffluens (Lücking Reference Lücking2008). A comprehensive study by Santesson (Reference Santesson1952) included eight foliicolous species of Tapellaria. Much later, an important contribution was made by Kalb & Vězda (Reference Kalb and Vězda1987) who discovered two corticolous species in Brazil. Lücking (Reference Lücking1992) treated seven species of Tapellaria from Costa Rica, while Kalb & Hafellner (Reference Kalb and Hafellner1992) described another corticolous species from the island of Madeira. Somewhat surprising was the discovery of the only known saxicolous species in the Himalaya region by Vězda & Poelt (Reference Vězda and Poelt1988). Lücking (Reference Lücking1999) provided further additions in his treatment of the family Ectolechiaceae (now a synonym of Pilocarpaceae) for Costa Rica. Cáceres (Reference Cáceres2007) reported a species from Brazil, whereas Breuss & Neuwirth (Reference Breuss and Neuwirth2007) presented six species in a collection from Costa Rica. In a complete revision of neotropical foliicolous lichens Lücking (Reference Lücking2008) discussed a wide range of features, ecological aspects and distribution patterns of Tapellaria. In the same year Flakus & Lücking (Reference Flakus and Lücking2008) published a new species from Bolivia. Lücking (in Lumbsch et al. Reference Lumbsch, Ahti, Altermann, Amo de Paz, Aptroot, Arup, Bárcenas Peña, Bawingan, Benatti and Betancourt2011) described another new Tapellaria species in an assembly of 100 new species and two new corticolous species from Florida (Lücking et al. Reference Lücking, Seavey, Common, Beeching, Breuss, Buck, Crane, Hodges, Hodkinson and Lay2011). A list of all known lichen species from the Golfo Dulce Region in Costa Rica (Neuwirth et al. Reference Neuwirth, Breuss, Huber and Weissenhofer2011) included Tapellaria species from the area. A new species list from the Galapagos Islands comprised six Tapellaria species (Bungartz et al. Reference Bungartz, Ziemmeck, Yánez Ayabaca, Nugra and Aptroot2016).
As a result, the genus Tapellaria currently comprises 20 species (13 foliicolous, five corticolous, one saxicolous and one species known to be both foliicolous and corticolous) occurring in tropical regions of America, Asia, Australasia, tropical Africa and the Hawaiian Islands. While collecting lichens in the Seychelles a foliicolous species of Tapellaria new to science was discovered growing on leaves of shrubs on the summit of Mt. Brulée and is described here.
Material and Methods
Morphological and anatomical investigations were carried out with a Euromex Mic 1642 ZHT dissecting microscope and a Reichert Neovar compound microscope. The chemistry of the type material was tested by spot reactions with KOH. Photographs of Tapellaria palaeotropica were taken using a Canon EOS 600D-camera connected to an LM-Scope camera adapter. Specimens were collected in February 2015 and the holotype is now deposited in LI and an isotype in the private herbarium of the second author.
The New Species
Tapellaria palaeotropica Neuwirth & Stocker-Wörgötter sp. nov.
MycoBank No.: MB 818730
Foliicolous Tapellaria close to T. nigrata with 3–5-septate, hyaline ascospores, 20–30×4–6 µm, a dark brown to reddish brown hypothecium 30–45 µm, and a purplish brown excipulum.
Type: Africa, Seychelles, Mahé, Montagne Posée Road, 4°42'S, 55°30'E, Mt. Brulée, Glacis La Reserve, Top Forest, 12 February 2015, E. Stocker-Wörgötter (LI 794441—holotype; hb. Stocker 107A—isotype).
Fig. 1 Tapellaria palaeotropica, holotype. A & B, habit of thallus and apothecia on leaf; C, section through apothecium showing epithecium, hymenium and hypothecium; D, apothecial margin and excipulum. Scales: A=10 mm; B=5 mm; C=0·15 mm; D=100 µm. In colour online.
Fig. 2 Tapellaria palaeotropica. A, 3–5-septate ascospores; B, ascospores in asci; C, campylidium; D, conidia. Scales: A & B=20 µm; C=0·3 mm; D=30 µm. In colour online.
Fig. 3 Tapellaria palaeotropica collecting site on Mt. Brulée, Mahé Island, Seychelles. In colour online.
Thallus crustose, epiphyllous, grey-green, smooth, shiny, dispersed in patches, K−.
Apothecia 0·1–0·4 mm diam., rounded, black, epruinose, flat, margin concolorous, constricted at the dark brown base; epithecium aerugineous, 10–15 µm; hymenium hyaline, 30–35 µm high; excipulum purplish brown; hypothecium dark brown to reddish brown, 30–45 µm, K+ purplish; paraphyses densely branched and anastomosing; asci clavate, 35–60×20–40 µm. Ascospores 6–8 per ascus, hyaline, 3–5-septate, narrowly ellipsoid to oblong with rounded ends, 20–30×4–6 µm.
Campylidia rare, 0·3–0·4 mm high, with large hood-shaped lobe, grey to white pruinose; conidia filiform, 3–7-septate, straight to curved, 15–45×1·5–2·0 µm.
Chemistry
Spot tests K−.
Etymology
The name refers to the discovery of this taxon in the Palaeotropics, in contrast to the similar, neotropical species Tapellaria major.
Ecology and distribution
So far the species has been collected only once on the summit of Mt. Brulée in the primary mountain rainforest of the Glacis La Reserve (Fig. 3) in an undisturbed area with a dense understory, surrounded by endemic palm trees. The lichen grew on smooth leaves of tropical shrubs between mossy granite boulders.
Discussion
Four species in the genus are similar to the new taxon as they share the foliicolous habit and transversely 3–5-septate ascospores. Tapellaria major differs by the aeruginous excipulum and its distribution in the Neotropics. Tapellaria albomarginata has a pale brown excipulum, smaller (14–20 µm long), 3(–4)-septate ascospores, distinctly grey-pruinose apothecial margins and neotropical distribution, whereas Tapellaria bilimbioides is palaeotropical and has pure black apothecia. Tapellaria nigrata has a brown excipulum lacking a purple tinge and larger ascospores (30–40 µm long) with 5–7 septa and is a pantropical species. Tapellaria nigrata is evidently the closest species and differs by its brown rather than purplish brown excipulum.
The authors are grateful to Robert Lücking for checking the characters, suggesting the description of the new species and reviewing the manuscript. We thank Elvis Nivette and the Seychelles Bureau of Standards for the research and collection permit which allowed the collection of specimens. We are also grateful to an anonymous reviewer for helpful comments and corrections. Josef Hafellner is thanked for providing important literature. ESTW is very grateful to the Austrian Science Foundation FWF for supporting the Projects P-23570-B06 and P-20887. ESTW would like to thank Katy Beaver (Conservation Action Group) and her husband for guiding us to the collection site.
