Introduction
Pisutiella phaeothamnos (Kalb & Poelt) S.Y. Kondr., Lőkös & Farkas (= Caloplaca phaeothamnos Kalb & Poelt) is a muscicolous species growing amongst moss (primarily Grimmia spp.) on base-rich volcanic rocks under arid or semiarid environmental conditions (Malíček et al. 2021). The known distribution range of the species extends to a few localities in Türkiye (Poelt and Kalb 1985, Vondrák et al. 2012), Greece (Malíček et al. 2021), Iran (Sohrabi and Sipman 2020) and the Canary Islands (Hafellner 1995). Herein, we document the first record of Pisutiella phaeothamnos in the Iberian Peninsula, thereby broadening its known range to encompass the southwestern region of Europe.
Material and methods
Specimens were collected in 2023 and 2024, in the volcanic area “Campo de Calatrava” in Mediterranean Spain. The samples were deposited in the MACB Herbarium (Faculty of Biology, Complutense University of Madrid). The nomenclature followed the Index Fungorum Partnership (2024).
Localities of sampling: Spain: Ciudad Real province, Ballesteros de Calatrava, la Conejera, 38º48’0.2’’N, 3º56’20.5’’W, 830 m a.s.l., among mosses on volcanic rocks, G. Aragón & G. F. Giménez, nº 1566, November 16, 2023, MACB. Ciudad Real province, Almagro, Granátula de Calatrava, Cerro Gordo, 38º49’51.8’’N, 3º44’23’’W, 785 m a.s.l., G. Aragón, G. F. Giménez & V. Negrón, nº 1610, January 29, 2024, MACB
Results and discussion
Pisutiella phaeothamnos is distinguishable from other crustose species of Caloplaca s. l. by the brown, minutely fruticulose thallus composed of branched lobes (4–5 mm tall), K–, ochraceous brown to orange apothecia (Fig. 1), and its ellipsoid and polarilocular spores of (7) 9–10 (11) × (4) 5–6 µm, and septum 3 µm wide. A comprehensive description of the species is documented in Poelt and Kalb (1985).
Fig. 1. Pisutiella phaeothamnos. A – volcanic rocks in “Cerro Gordo”, B – P. phaeothamnos among mosses in volcanic rock (scale bar = 1 cm), C – ochraceous brown apothecia (scale bar = 2 mm), D – minutely fruticulose thallus (scale bar = 2 mm) (Photo: G. Aragón).
The species grows among bryophytes (Grimmia decipiens (Schultz) Lindb.) on volcanic rocks, under dry and sunlit conditions, at elevations ranging from 750 to 850 meters (Fig. 1). It is found on moderately inclined surfaces together with Caloplaca stillicidiorum (Vahl) Lynge and small thalli of Cladonia foliacea (Huds.) Willd. and Protoparmeliopsis bolcana (Pollini) Lumbsch, which partially cover the bryophyte surface (Fig. 1).
The habitat was similar to that previously reported for Pisutiella phaeothamnos. The species appears solely amongst mosses in volcanic rocks at altitudes of 500–1700 m a.s.l. in Eastern Europe (Poelt and Kalb 1985, Vondrák et al. 2012, Malíček et al. 2021) and at elevations from 1500 to 1850 m a.s.l. in the Canary Islands (Hafellner 1995).
The new site is located within a vast volcanic region in central Spain, about 5,000 square kilometers in area (Becerra-Ramírez et al. 2020). The volcanic formations resulted from low-explosivity events dated to between 700,000 and 800,000 years ago and are primarily composed of alkaline rocks from the basalt series (Becerra-Ramírez et al. 2020). The predominant land use in this area is extensive agriculture of cereals, olive and almond trees, and sheep livestock management (Becerra-Ramírez et al. 2020).
Pisutiella phaeothamnos is reported here from SW Europe for the first time and its distribution area is now enlarged to include the Iberian Peninsula (Fig. 2). The nearest locality is situated in the Canary Islands (Hafellner1995).
Fig. 2. Global distribution of Pisutiella phaeothamnos. White cross: the new localities. Scale bar = 1000 km (derived and adapted from Google Earth).