Mycobank MB 518279
Thallus areolate to squamulose (subsquamulose), forming dispersed patches of one to few areoles associated with thalli of, among areoles or overgrowing it, Protoparmelia montagnei (Fr.) Poelt & Nimis and occasionally with nearby Dimelaena oreina (Ach.) Norman. Areoles irregular, rounded to angular by pressure, sometimes lobulate, 0.5–3.5 mm in diam, up to 2.25 mm thick, commonly forming a short stipe and becoming squamulose; upper surface yellow to pale yellow or greenish yellow, usually dull, convex to concave, smooth to rough, sometimes fissured; lateral/lower surface ± smooth, yellow-brown to dark brown or carbonized black. Upper cortex paraplectenchymatous, (35–)40–125 µm thick depending on development of areoles, cells usually indistinct, ± globular, in several layers, upper layers brown-yellow pigmented, lower layers hyaline, containing granules of various sizes; syncortex lacking or up to 25 µm; lateral/lower cortex continuous with upper cortex, but with brown or dark brown to commonly carbonized black pigmented upper layers. Algal layer continuous, up to 200 µm, usually uneven lower; photobiont chlorococcoid, cells 6–15 µm in diam. Medulla hyaline to dirty white, continuous with broad to forming stipe attaching tissue. Apothecia immersed, aspicilioid, up to 0.7 mm in diam, 1–8 per areole, sometimes confluent, punctiform to round or irregular; disk brown to red, concave to ± plane, rough. Proper excipulum cupular, surrounded by algae, ± prosoplechtenchymatous, 12–30 µm wide, fan expanding around surface, hyaline to yellowish. Hymenium hyaline to yellowish, 125–250(–300) µm tall; paraphyses 1.5–3 µm wide at the base, up to 4.5 µm at slightly pigmented apices; epihymenium brownish-yellow, coherent, with yellowish granules, up to 20 µm tall. Hypothecium, including subhymenium, hyaline to slightly yellowish, up to 150 µm. Asci clavate, 70–130 × 18–30 µm, more than 100-spored, outer wall K/I + blue, tholus K/I–. Ascospores hyaline, simple, elongate to cylindrical, 4–6.01–7.5 × 1.5–2.78–3.5 µm, long/breath ratio 1.66–3, l/b mean value 2.21 (n = 150). Pycnidia immersed, punctiform, ± spherical, up to 210 µm in diam, ostiole inconspicuous or yellow to red-brown, wall hyaline to yellowish, surrounded by algae. Conidia hyaline, bacilliform, 2.5–5 × 1–2 µm. Spot tests in cortex and medulla: K–, C–, KC–, P–, I–; thallus: UV ± orange. Secondary chemistry: epanorin (major) with or without rhizocarpic acid (traces) (8 TLC, 3 HPLC).
The new taxon falls into the mediterranean Acarospora species group (Clauzade & Roux, 1981) with yellow, non effigurate margin, silicolous thalli, associated with other lichens, brown to red apothecia and K–, C–, white medulla. Acarospora flavisparsa is probably closest to A. microcarpa (Nyl.) Wedd. (Magnusson, 1929, 1936; Poelt & Vezda, 1977; Clauzade & Roux, 1981; Egea & Llimona, 1981), apparently a juvenile or specific parasite on silicolous Diploschistes actinostomus (Ach.) Zahlbr. also growing on close lichens (Poelt, 1958; Clauzade & Roux, 1981; 1985; Sipman & Rausch, 1999; Roux et al., 2006). Furthermore, A. microcarpa differs in having: areoles never lobulate, squamulose or shortly stalked and with yellowish to pale lateral surface, smaller areoles and apothecia (up to 2 and 0.4 mm respectively), shorter cortex, algal layer, hymenium and hypothecium (up to 70, 100, 140 and 35 µm respectively), narrow paraphyses at the base (up to 2 µm), ellipsoidal ascospores [3–6 × 2.5–4 µm, length/width ratio 1.28–1.85, l/b mean value 1.6 (n = 80)], rhizocarpic acid as major secondary substance (5 TLC, 8 HPLC, Leuckert & Buschardt, 1978) and occurring below 700 m altitude in France, Greece, Italy, Morocco and Spain, with optimum in the Thermo-Mediterranean belt (Egea & Rowe, 1987; Nimis & Poelt, 1987). Although A. flavisparsa grows primarily dispersed within the areoles of P. montagnei and D. oreina, it does not appear to be an obligatory or host-specific juvenile parasite, but a close association with those lichens is assumed. On the contrary, in some specimens of A. microcarpa the thallus was observed growing endokapylically at first, becoming successively epikapylic and independent and forming little thalli up to 2 cm diam on D. actinostomus [Follmann, Lich. Exs. Sel. Cass. 182 (MAF)]. Acarospora heufleriana Körb., frequently invades other lichens but differs in its ellipsoid to subglobose ascospores, rhizocarpic with or without norstictic acid as major substances, and ± continuous thalli often with pruina (Clauzade & Roux, 1981; Knudsen, 2007). Acarospora charidema (Clemente ex Colmeiro) Llimona is a thermophilic pioneer, not a parasitic lichen, with robust convex squamules up to 4 mm wide, apothecia up to 1.5 mm wide and with a hymenium up to 140 µm tall (Clauzade & Roux, 1981; Egea & Rowe, 1987). Acarospora epithallina H. Magn. is also similar to A. flavisparsa, but grows as a juvenile parasite on Acarospora hilaris (Dufour) Arnold, forming up to 5 mm wide convex squamules, ± globose ascospores and producing rhizocarpic and gyrophoric acids (Leuckert & Buschardt, 1978; Clauzade & Roux, 1981).
The epithet refers to the scattered yellow squamules growing among other lichens.
Currently, Acarospora flavisparsa is known from continental mediterranean areas in Portugal (Tras os Montes) and Spain (Madrid, València and Zamora provinces). The species occurs on acid rocks in inland areas, at 550–1480 m, on exposed ± vertical rock walls from continental dry to sub-humid places, associated with Protoparmelia montagnei and sometimes with Dimelaena oreina.
Type:—SPAIN: Madrid: Sán Lorenzo de El Escorial, near Silla de Felipe II; 40º35’N, 04º09’W, 1080 m; associated with Protoparmelia montagnei on granite; Jul 1986, Florido & Rico 1133/1 (holotype MAF-Lich. 16463).
Additional specimens examined (paratypes):—PORTUGAL. Tras os Montes e Alto Douro: Bragança, IP4 road to the south, Sabor river valley, 3 km to Lagoa, Rico 3649/2 (MAF). SPAIN. Zamora: Pereruela, Las Enillas, Sep 1998, Crespo & Blanco s.n. (MAF). Madrid: between El Berrueco and Berzosa del Lozoya, El Villar dam, Barreno & Rico 275/1, 276/3 (MAF). La Cabrera, Sierra de La Cabrera, El Mojón summit, Rico & Florido 380/2, 385/1, 434/2, 451/2, 452/1 (MAF). Manzanares el Real, La Pedriza, Collado de Valdealcones, Rico & Barreno 589/4, 590/1, 621/3, 632/1 (MAF); ibid., El Chivato stream, Rico & Barreno 477/3, 489/2 (MAF). Lozoya, El Chaparral, Rico & Manrique 770/1 (MAF). Collado-Mediano, Cerro del Castillo, Rico 863/2, 901/6, 903/3 (MAF). Robledillo de la Jara, Collado de Fragüela, Rico & Manrique 1093/1 (MAF). Robledo de Chavela, El Almojón summit, Rico 805/1, 807/3 (MAF). Zarzalejo, Dec 1988, Valladares s.n. (MAF). València: Serra, Font del Berro, Dec 1990, Calatayud s.n. (VAB). Castelló: Alfondeguilla, Nevera summit, Jun 1989, Calatayud s.n. (VAB).
Sicut Acarospora microcarpa sed cum Protoparmelia montagnei consociata, squamulis et ascomatibus majoribus, squamulis latere carbonato nigro, paraphysibus crassibus, ascosporis elongate-cylindraceis et epanorinam continente differt.