Ramalina alisiosae Pérez-Vargas & Pérez-Ortega, 2014

Ramalina alisiosae Pérez-Vargas & Pérez-Ortega View in CoL , sp. nov. ( Fig. 1 View FIGURE 1 & 2 View FIGURE 2 )

MycoBank MB803780

Type:— SPAIN. Canary Islands: El Hierro, Sabinosa, Camino hacia la Fuente de Mencáfete , 27°43’59”N, 18°05’14”W, 1121 m, 29 July 2011, S. Pérez-Ortega & M. Arróniz-Crespo 1690 (holotype TFC Lich 13283 ! GoogleMaps ; paratype, ibidem, 1692; TFC Lich 13284 ! GoogleMaps ).

Thallus corticolous, yellowish-greenish, shrubby to subpendulous ( Fig. 1A View FIGURE 1 ), up to 12 cm long, with a number of moderately branched laciniae from a common holdfast. Laciniae stramineous, smooth, quite rarely fenestrate ( Figs. 1G & H View FIGURE 1 ), slender and fragile, subterete, flattened into branching points, up to 1mm wide but usually less and tapering gradually; apices not hook-shapped. Sometimes the diameter of the terete branches varying, given a pseudonodose appearance. Occasionally neighbouring branches are merged and some fenestrations are present; cracks and pseudocyphellae absent but short, divergent branchlets present, scattered along the thallus, with fine apices that sometimes develop small granules ( Fig. 1E View FIGURE 1 ). Soralia present ( Figs. 1C & D View FIGURE 1 ), numerous, orbicular to hemispherical, convex, efflorescent, frequently giving rise to minute blanchlets ( Fig. 1F View FIGURE 1 ) producing branchlets. Soredia granular, of 40–70 µm diam. Anatomy farinacea - type ( Krog & Østhagen 1980a). Epinecral layer 4-8 µm thick ( Fig. 2B View FIGURE 2 ), cortex prosoplechtenchymatous well developed, 25–45 µm thick ( Figs. 2A, C & E View FIGURE 2 ), composed of hyphae with very thin lumina (ca. 0.5 µm in diam.); cortical layer shows refringent granules ( Fig. 2B View FIGURE 2 ) that disappear in K. Beneath the cortex there is a paraplechtenchymatous chondroid cylinder of uneven thickness with ridges jutting into the medulla ( Figs. 2A, C & D View FIGURE 2 ), hyphae, running parallel to the thallus surface, are organized in bundles ( Fig. 2D View FIGURE 2 ). Medulla very lax and highly hydrophobic. Apothecia very rare, lateral, up to 1 mm in diam. shortly stalked, not or shortly spurred ( Fig. 1B View FIGURE 1 ). Disc pale yellow to flesh coloured, plane, slightly pruinose; thalline margin present, persistent, contorted, constructed by entwined hypha. Paraphyses simple to forked ( Fig. 2F View FIGURE 2 ), not or only slightly enlarged apically. Asci elongate-clavate, 8-spored 36–44 (–50) × (10–) 15–23 µm ( Fig. 2G View FIGURE 2 ). Ascospores 1-septate, colourless, broadly ellipsoid to slightly kidney-shaped (9.8–) 13.9–15.1 (–19.1) × (3.9–) 5.8–6.3 (–7.9) µm (n= 30), ( Figs. 2H, I & J View FIGURE 2 ). Pycnidia not seen.

Chemistry:— Cortex K+ yellowish, C–, KC+ yellow, Pd–, UV–. Medulla and soralia K+ yellow turning red, C–, KC–, Pd+ orange, UV–; norstictic and usnic acids detected by TLC.

Etymology:— The specific epithet alisiosae is derived from alisios, the Spanish word for moisture-laden Atlantic winds with high humidity blowing from the NE, and the responsible for the frequent low-level cloud cover and the existence of the laurel forest and the lush lichen communities in these places, where this new species was collected.

Distribution and ecology:— The new species grows epiphytic on Morella faya together with other species of Ramalina and Usnea Dill. ex Adanson (1763: 7) in the laurel forest. This type of forest is characterised by perennial broadleaf laurel leaf trees, although at the top of the ridges ericoid species can dominate ( Del Arco et al. 2010). It shows a high biodiversity, a high degree of endemism, and relatively stable and mild temperatures with high humidity due to the trade winds (alisios). So far, the new taxon is only known from the type locality in El Hierro Island (Canary Islands). In spite of intensive sampling that we have carried out in most of the Macanonesian islands we have not found this species in other areas.

Notes:— The new species is characterized by having slender and mainly subterete branches tapering gradually, the presence of branchlets, efflorescent soralia and apothecia, cortex and ascospores size and chemistry. The phylogenetic analyses showed the phylogenetic affinity of the new species to the R. farinacea group ( Fig. 3 View FIGURE 3 ), especially with R. implectens Nylander (1870: 116) , which is not forming a different clade from R. alisiosae in the phylogenetic tree inferred from ITS sequences. However, in the ITS sequences of both R. alisiosae specimens we found 10 nucleotides differing from R. implectens , supporting the independence of the new species. Morphologically, the new species resembles some taxa in the R. farinacea group (table 2). Ramalina farinacea (L.) ( Acharius 1810: 606) is a corticolous species with flattened laciniae and orbicular, farinose, delimited and concave soralia ( Krog & Østhagen 1980a; Fletcher et al. 2009). Chemically it is a very diverse species ( Álvarez et al. 2001; Stocker-Wörgötter et al. 2004). However, all chemotypes with norstictic acid have salazinic as accessory substance, whereas we have not detected the latter in samples of R. alisiosae . Although the anatomy of R. alisiosae belongs to the farinacea - type, the cortex is thicker (25–45 µm vs 15–20 µm in R. farinacea ). Also, the ascospores of the new species are longer and wider than the Canarian specimens of R. farinacea . Other corticolous species of Ramalina with similar morphology include R. dendriscoides Nylander (1876: 412) and R. peruviana Acharius (1810: 599) . The former has a shrubby and smaller thallus, thinner cortex, different chemistry and lacks apothecia ( Swinscow & Krog 1988; Kashiwadani & Kalb 1993). The latter is a densely and intricately branched small fruticose species, weakly striate in basal parts, with punctiform soralia, and different chemistry (substances of the sekikaic acid chemosyndrome). The presence of these species in the Canary Islands is doubtful. Hernández-Padrón & Pérez-Vargas (2009) included both species in the Checklist of the Lichen Biota of the Canary Islands. However, a review of these records has shown some problems. Ramalina dendriscoides is mentioned for the Canaries by Klement (1965) but in its form nodulosa . The taxonomic position of this taxon is uncertain, so, we consider, agreeing with Hafellner (1995) the presence of this species very doubtful in the Canary Islands. The most recent and only record of R. peruviana in the Canarian Archipelago was reported by Aptroot & Schumm (2008) but no information about the locality was given.

The fertile Ramalina implectens is closely related to the new species. It is known from Macaronesia and the Southern part of the Iberian Peninsula. It is mainly a corticolous species, although rarely found on rocks. The main distinguishing feature is the absence of soralia in R. implectens . In addition, the laciniae do not develop branchlets; the cortex is thinner (10–15 µm vs 25–45 µm in R. alisiosae ); apothecia are numerous and frequently in geniculate branches and spurred; moreover, the spores have a subterminal pseudoseptum ( Krog & Østhagen, 1980a) not seen in R. alisiosae and they are larger and wider in the new species.