Leightoniomyces canariensis Etayo & Pérez-Vargas, 2013

Pérez-Vargas, Israel, Etayo, Javier & Hernández-Padrón, C., 2013, New species of lichenicolous fungi from the Canary Islands, Phytotaxa 99 (2), pp. 58-64 : 58-60

Leightoniomyces canariensis Etayo & Pérez-Vargas , sp. nov. ( Fig. 1 ) Mycobank MB 800608

Similar to L. phillipsii but with ellipsoid conidia with different ornamentation in transversal rows and narrower and larger conidiogenous cells.

Type:— SPAIN. Canary Islands: La Palma, Caldera de Taburiente National Park , “Hacienda El Cura, curva del Manzanillo”, 620 m, on crustaceous lichen on volcanic rocks, 27 December 1999, J. Etayo & M. Martín 17688 (holotype TFC-Lich!; isotype herb. Etayo!)

Mycelium immersed. Synnemata indeterminate, erect, rigid, black 180–250 µm tall; stipe 20–45 µm wide, abruptly expanded into a brown-black globose mass of conidiogenous cells and conidia, 70–125 µm diam. Stipe composed of vertically orientated, compacted, septate, dark brown (lighter near the base), smooth, 100– 120 µm long and ca. 1 µm wide hyphae. All structures are K – and I –. Conidiogenous cells holoblastic, annellidic, with 1–2 percurrent proliferations, integrated, terminal, arising only at the apices of the synnemata, densely crowded, cylindrical, sometimes enlarged in the centre, hyaline to brownish, rough-walled, 14–30 × 2.5–4 µm. Conidia arising single at the apices of the conidiogenous cells, dry, with schizolytic secession, adhering in a dense, globose head, not catenate, simple, ellipsoid to pyriform, with one or two large oil guttules, gold brownish to brown, (11–)12–16(–17) × 6.5–8 µm (n=25), with a persistent pore-like scar in the attachment; wall rugulate forming transversal rows, verrucae linear, smaller than 1 µm high.

Etymology:— The epithet canariensis is derived from the name of the area (the Canary Islands) where the new species occurs.

Distribution and ecology:— This new species is known only from the type locality, a Canary pine woodland in La Caldera de Taburiente National Park (La Palma island). Pine woodland is the largest forest community of the islands. It is an open formation characterized by Pinus canariensis Sweet ex Spreng. , growing above evergreen laurel forest in the northern windward cloud zone and directly above thermosclerophyllous woodland in the south of the islands. It extends over a wide territory with precipitation of 450– 550 mm and average annual temperature of 11-15ºC ( Del Arco et al. 2010). Leightoniomyces canariensis grows on crustaceous, very thin, greenish sterile lichen species on volcanic rocks. Other lichen species in the same rocks are Trapelia coarctata (Turner ex Sm.) M. Choisy , Moelleropsis nebulosa (Hoffm.) Gyeln. , Leptogium cf. teretiusculum and Diploicia sp.

Discussion:— Leightoniomyces canariensis resembles L. phillipsii (Berk. & Leight.) D. Hawksw. & B. Sutton , the only known species in this genus, so far. That species is known from the British Isles, the Azores and North and South America, and it has been treated in several papers (e.g. Ellis 1971, Hawkswoorth 1977, Mc. Cune & Stone 2009, Piccolo Grandi 2012, Seifert et al. 2011). Leightoniomyces phillipsii , however has darker (dark brown to almost black) and subsphaerical conidia (8–14 µm diam.) that are extremely coarsely verrucose, with individual angular, dark brown verrucae, 2–4 µm diam. ( Hawksworth 1977). Futhermore, in L. phillipsii the conidiogenous cells are wider and shorter (7–17 × 5–7 µm) and stipe cells are wider (of 1.5– 2.5 µm) ( Hawksworth 1977). Leightoniomyces phillipsii has been found to be lichenicolous on terricolous lichens: Thrombium epigaeum (Pers.) Wallr. and Steinia geophana (Nyl.) Steiner , both with Leptosira algae, which let Hawksworth (1977) point out that this fungus might be algicolous, and not lichenicolous. However, it has been also recorded growing on bryophytes and on bare patches of soil, and no clear intimate association with lichen, algae or bryophytes has been found in North America ( McCune & Stone 2009). Recently, it has been isolated from the decomposing roots of Calathea zebrina (Sims) Lindl. and Euterpe edulis Mart. in South America ( Piccolo Grandi 2012).

Superficially, the new species also resembles Arborillus llimonae Munt. -Cvet., but that species has larger synnemata (500–1000 × 175–400 µm), different conidial formation, greenish and smaller conidia and grows on Diploschistes thalli ( Muntañola-Cvetkovic & Gómez-Bolea 1998).

Figures

FIGURE 1. Leightoniomyces canariensis, holotype. A. Habit; scale: 0.25 mm. B. Synnema; scale: 100 µm. C-D. Conidiogenous cells and conidia; scale: 10 µm.