Umbilicaria deusta
≡Lichen deustus L., Sp. Pl.: 1150 (1753) nom. cons. (see Jørgensen et al. 1994a, 1994b; Gams 1996).
Description : Thallus monophyllous, occasionally appearing polyphyllous, central parts flat or obscured by squamiform isidia near umbilicus, the lobes free or somewhat overlapping, 2–4 cm diam., rosette-forming and ±flat when young, becoming irregularly lacerate, and contorted with age, margins slightly thickened, irregularly notched or incised, noticeably curled under, coarsely granular to isidiate, without rhizinomorphs, flabby, pliable when moist, rigid, cartilaginous, brittle when dry. Upper surface deep olive-green suffused brownish when moist, dark greenish black to brown-black when dry, grey-white and granular-roughened above umbilicus, when central parts are free of isidia, generally densely isidiate; sometimes with superficial, gall-like pustules of * Clypeococcum. Isidia minute, granular, globular at first, soon becoming flattened-squamulose, squamules irregularly lobed, 0.1–1.5 mm diam., scattered to crowded-imbricate, margins irregularly incised, concolorous with upper surface or darker. Lower surface brown-black in patches, to pale-fawnish, often piebald, smooth to irregularly pitted or minutely and irregularly cracked in places, or split in parallel radiating lines from umbilicus to margins, rarely with broad fenestrations, to 2 mm diam., and often with noticeable invaginations corresponding to * Clypeococcum infections on upper surface, but without wrinkles or ridges. Umbilicus compact, 2–3 mm diam., without radiating narrow ridges or lamellar structures. Rhizinomorphs absent. Apothecia and pycnidia not seen.
Chemistry : Gyrophoric acid (major), lecanoric acid (minor), and umbilicaric acid (minor).
S: Otago (Mt Pisgah, Kakanui Mts). It is a rather rare lichen, which grows on horizontal to weakly sloping schist surfaces receiving periodic seepage or water trickles ( it has this particular ecology in the Northern Hemisphere), or on the floors of shallow overhangs where it co-occurs with the more commonly encountered U. grisea (characterised by marginal parasoredia). It associates with the following lichens: Bryoria austromontana, Lecanora bicincta, Rhizocarpon geographicum, R. grande, Sporastatia testudinea, Umbilicaria cylindrica, U. decussata, U. durietzii, U. grisea, U. hyperborea, U. nylanderiana, U. polyphylla, Usnea acromelana, U. ciliata, U. subcapillaris and U. torulosa (Galloway & Ledingham 2006). The upper surface of all of the thalli seen of U. deusta were infected with the characteristic, blister-like galls of the lichenicolous fungus * Clypeococcum grossum (Galloway 2002c). Known also from Great Britain, Europe, Scandinavia, Greenland, Svalbard, the Ukraine, Asia, Japan, and North America (Lynge & Scholander 1932; Frey 1933; Dahl et al. 1937; Dahl 1950; Llano 1950; Hakulinen 1962; Krog 1968; Dahl & Krog 1973; Yoshimura 1974; Poelt 1977; Creveld, 1981; Degelius 1982; Purvis et al. 1992; Nimis 1993; Santesson 1993; Türk et al. 1993; Goward et al. 1994b; Esslinger & Egan 1995; Elvebakk & Hertel 1997; McCune & Geiser 1997; Geiser et al. 1998; Glew 1998; Hinds & Hinds 1998; McCune 1998; Diederich & Sérusiaux 2000; Scholz 2000; Brodo et al. 2001; Hafellner & Türk 2001; Llimona & Hladun 2001; Coppins 2002b; Kondratyuk et al. 2003; Kurokawa 2003; Nimis & Martellos 2003; Hestmark 2004; Santesson et al. 2004; Sérusiaux et al. 2004; Elvebakk & Bjerke 2006). It is not known from Africa, South America, New Guinea, Australia or Antarctica.
Bipolar
Illustrations : Llano (1950: 257, pl. 18, fig. 3); Yoshimura (1974: pl. 23, fig. 206); Jahns (1980: 219, fig. 526); Moberg & Holmåsen (1982: 154); Goward et al. (1994b: 128, fig. 1a); Wirth (1995a: 933; 1995b: 600, pl. 60A, fig. C); McCune & Geiser (1997: 293); Brodo et al. (2001: 702, fig. 862).
Umbilicaria deusta is characterised by: the laminal and marginal minutely granular to flattened-squamulose isidia, a unique character for the genus.
