Phytotaxa 284 (4): 231–262 http://www.mapress.com/j/pt/ Copyright © 2016 Magnolia Press Article PHYTOTAXA ISSN 1179-3155 (print edition) ISSN 1179-3163 (online edition) Accepted by Jian-Kui Liu: 1 Nov. 2016; published: 18 Nov. 2016 http://dx.doi.org/10.11646/phytotaxa.284.4.1 231 A revision of the genus Orbilia in the Canary Islands LUIS QUIJADA 1* , HANS-OTTO BARAL 2 & ESPERANZA BELTRÁN-TEJERA 1 1 Departamento de Botánica, Ecología y Fisiología Vegetal, Universidad de La Laguna, Tenerife 38200, Canary Islands, Spain. 2 Blaihofstr. 42, D-72074 Tübingen, Germany. * Corresponding author; Email: lquijull@gmail.com Abstract Based on field work and herbarium studies, a taxonomic revision of the genus Orbilia in the Canary Islands was carried out. Eighteen species of the genus are recognized in the present study. Eight of these are new records for the archipelago (Orbilia cejpii, O. euonymi, O. flavida, O. flavidorosella, O. hesperidea, O. scolecospora, O. vinosa and O. vitalbae). Three of them are here described in detail (O. cejpii, O. flavida and O. vitalbae), because they were not reported again since their first publication. Corrections and clarifications about the identity of four previously reported species (O. alnea, O. auricolor, O. delicatula and O. epipora) are provided, being renamed to O. eucalypti, O. tenuissima, O. xanthostigma, and O. dryadum, respectively, the last one being a new combination for O. alnea var. dryadum. Two species with a rather short original diag- noses reported for the Canary Islands are redescribed in detail (O. corculispora and O. gambelii), and those being endemic for the archipelago are illustrated and briefly discussed (Orbilia adenocarpi, O. asomatica, O. pisciformis and O. succulenti- cola). A key for the identification of these species, a discussion about closely related taxa, notes on their global distribution, and ecological data are provided. Key words: Biodiversity, Macaronesia, Orbiliomycetes, Spain, taxonomy Introduction In less than a decade, the genus Orbilia Fr. has been subjected to an important transition with systematic and taxonomic changes, combined with new ecological and economic aspects. Historically placed in Helotiales Nannf., the genus was transferred in 2003 to a newly erected order and class (Orbiliales Baral, O.E. Erikss., G. Marson & E. Weber and Orbiliomycetes O.E. Erikss. & Baral). Nowadays, the morphological concept of the genus has changed considerably, resulting in (1) the synonymization of presently six teleomorphic genera (Hyalinia Boud., Habrostictis Fuckel, Cheilodonta Boud., Radotinea Velen., Orbiliaster Dennis, Orbiliella Kirschst; Baral in Eriksson et al. 2003), (2) the separation of the new genus Hyalorbilia Baral & G. Marson (Baral & Marson 2001), (3) the discovery of new infrageneric boundaries (for instance, Orbilia subgenus Hemiorbilia) based on ascus morphology (Baral 1994), and (4) the use of sensitive morphological elements of the living cells which have rarely been used in the past to differentiate species (cytoplasmic bodies, vacuolar bodies, and spore bodies; Baral 1992). Pfister (1994) and Pfister & Liftik (1995) reported the predacious capabilities of some anamorphs and their connection to members of Orbilia, which stimulated research on further anamorph-teleomorph connections and phylogenetic relationships in this group of fungi (Hagedorn & Scholler 1999, Liu et al. 2005, etc.). Since 1990, the exploration of xeric microniches and arid ecosystems has resulted in the discovery of a huge number of undescribed drought-tolerant species in comparison to a comparatively small number of drought-sensitive species, which will be described in a comprehensive monograph of Orbiliomycetes (Baral et al. in prep.), in which the authors recognized ca. 450 species with a known teleomorph (Baral 2015). This is in contrast to the deeply underestimated number of only ca. 58 previously recognized (Kirk et al. 2008). Orbilia is one of the most diverse fungal genera in the Canary Islands. The first work on the genus was done by Korf in 1992, who reported eight species from the archipelago: O. alnea Velen., O. auricolor (A. Bloxam ex Berk. & Broome) Sacc., O. delicatula (P. Karst.) P. Karst., O. epipora (Nyl.) P. Karst., O. luteorubella (Nyl.) P. Karst., O. lunata Korf, O. inflatula (P. Karst.) Sacc., and O. occulta (Rehm) Sacc. Two of them, Orbilia lunata and O. inflatula, have been transferred to the genus Hyalorbilia in the meantime (Baral & Marson 2001, Quijada et al. 2015a). Based on the re-examination of a part of these collections (Baral et al. in prep.), Korf’s report of O. occulta includes a mixture of two