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Family: Teloschistaceae
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Thallus pale to medium grey or whitish grey, 0·03–0·5(–0·7) mm thick, rimose to irregularly cracked areolate with +/- verruculose surface; areoles varying much in size, 0·1–1·8 mm. Apothecia always present and usually abundant, adnate to sessile, round to irregular, biatorine but usually with some algae at the base of the excipulum, 0·3–1·2 mm wide; disc slightly concave to strongly convex, dark orange to brownish or dark reddish orange in young apothecia, later more ferruginous brown to dark brown to brown-black, with or without orange pruina; proper margin in flat to moderately convex apothecia 20–100 μm, but in strongly convex apothecia reflexed and +/- excluded, sometimes with oil-droplets, raised above or level with disc, rather even, concolorous with disc or darker, sometimes black, with radiating hyphae in the proximal part, but +/- isodiametric cells with rather thick cell walls below the hypothecium, hyaline in interior parts but often bluish black near surface, with varying amounts of orange external crystals; thalline margin absent, but algae are sometimes present at the base, occasionally filling most of it; epithecium with varying amounts of Lecidea-green, in young stages usually with granular epipsamma of brownish orange crystals, but these often decrease with age; hymenium (65–)80–100(–120) μm thick, hyaline; hypothecium (30–)50–100(–150) μm thick, usually with oil-droplets, hyaline; paraphyses simple to somewhat branched above, 1–2·5 μm, upper cells moderately widened to 3–4(–5) μm. Asci clavate, c. 60 X 20 μm, 8-spored; ascospores polaribilocular, broadly ellipsoid to ovoid, (12·0–)14·0–18·0(–19·0) X (6·0–)7·0–9·0(–11·5) μm, septum (3·0–)4·0–7·0(–8·0) μm, ratio septum/spore length width (0·21–)0·29– 0·41(–0·50) μm. Pycnidia not observed. Chemistry. The thallus is K-, C-, P-and UV-. The apothecia contain dominant proportions of parietin, emodin and 7-chloroemodin and their oxidation products as well as minor proportions of fragilin, emodinal and citreorosein based on the absorbtion at 270 nm. This chemistry corresponds to the groups C3 and C4 of Søchting (2001). The excipulum and epithecium also contain varying amounts of Lecidea-green(K-, N+ brownish purple). Habitat and distribution. Caloplaca fuscorufa grows on various kinds of rock, often on slightly calciferous types, but also on pure acidic rocks and limestone. It usually grows on vertical to horizontal surfaces of solid rock, but it has also been found on pebbles. In Sweden and Norway most collections have been made near water, mainly by streams or minor brooks or from seepage surfaces. On Svalbard it seems to occur in drier situations. Almost all habitats are more or less sun-exposed, although there are collections from N-facing situations. In the northern part of its distribution it occurs from sea level up to c. 800 m altitude, but in the southern part it has been found from c. 500 m up to 1420 m (Finse in Norway). Caloplaca fuscorufa is probably rather common in south of Sweden, Norway and on Svalbard. It is not yet known from Finland and may not occur there. A study of all the material under C. crenularia in H did not reveal any specimens belonging to C. fuscorufa. The species has clearly been misunderstood and neglected, and its full distribution range is probably yet to be established. Remarks. From both the statistical and the molecular analyses it is clear that C. fuscorufa differs from C. crenularia and other similar species. It differs from C. crenularia in the larger spores with larger septa and in the colour of the apothecia. The proper margin also differs in often being more flexuose in C. crenularia and slightly thinner. In addition, C. crenularia usually has conspicuous, ferruginous pycnidia while no pycnidia have been observed in C. fuscorufa. Forms of C. fuscorufa with blackish proper margin and orange disc are similar to C. exsecuta, however, the chemistry of this species lacks all chlorinated anthraquinones. The apothecia in C. exsecuta are usually smaller with more yellowish, or greenish orange discs and the hypothecium is brownish instead of hyaline. Finally, the spores are clearly smaller with smaller septa in C. exsecuta. Some forms of C. conciliascens (Nyl.) Zahlbr. with orange discs (mainly young apothecia) are similar to C. fuscorufa, but the spores in this species are clearly smaller, 10–14 X 4·5–6 μm, with shorter septa, 3·5–6 μm. However, the taxonomy of C. conciliascens and similar species is not yet clarified and will be dealt with separately. Caloplaca fuscorufa is also separated from C. ammiospila, as this taxon has a poorly developed, granular thallus, and has shorter, 2–5 μm, spore septa, and usually grows on mosses, plant debris or wood and only very rarely on stone. Most of the material of C. crenularia present in the Nordic herbaria from Sweden, Denmark, Norway and Finland has been included in the present study. We can therefore say that it is likely that C. crenularia is absent from northern Sweden, except for a few places near the coast. In Norway C. crenularia is also found in the far north, but again only relatively close to the coast. In Sweden Caloplaca fuscorufa has mainly been determined as C. crenularia, but in Norway and on Svalbard often as C. exsecuta or referred to as an ‘‘unknown’’ taxon. There seems to be a small overlap in distribution ranges between the species, at least in central and northern Norway (Fig. 3). |