Description.Thallus thin, light to dark grey, often with a bluish or brownish tinge, areolate; areoles scattered or contiguous, to 0.40-0.60(-0.80) mm wide; surface plane to slightly convex, matt; margin indeterminate; prothallus lacking (or brown, around areoles Tønsberg 1992); vegetative propagules present; areole surfaces rapidly breaking into soredia, forming discrete soralia, the same size as the areoles but tending to form a continuous crust over bryophytes; soredia sometimes dark grey at first, usually bluish- or greenish-grey, rarely light grey, always lighter than thallus. Apothecia very rare, narrowly attached, mainly poorly developed (poriform), contiguous or not, to 0.50-0.55 mm in diam.; disc mostly concave, becoming plane, brown, becoming dark brown to black; margin concolourous with thallus, prominent, 0.05-0.10 mm wide, entire, persistent; excipular ring sometimes present, confluent. Apothecial Anatomy. Thalline exciple 70-80 µm wide laterally; cortex ca. 10 µm wide laterally, structure often occluded by crystals; epinecral layer absent; crystals present in cortex, absent in medulla; cortical cells to 5.0-5.5 µm wide, pigmented or not; algal cells to 11.0-14.5 µm long; thalline exciple 20-110 µm below; cortex ca. 10 µm wide, cellular; proper exciple hyaline, ca. 15 µm wide laterally, expanding to ca. 30 µm above; hypothecium 40-60 µm deep; hymenium 110-120 µm high, not inspersed; paraphyses ca. 2.5 µm wide, conglutinate, apices to 5.0-5.5 µm wide, lightly pigmented, immersed in dispersed pigment forming a light red-brown epihymenium. Ascospores 8/ascus but intact, mature asci not seen, Pachysporaria-type I, (18.5-)21.0-23.0(-26.0) x (10.0-)12.0-13.5(-15.5) µm, average l/b ratio 1.6-1.9, mature spores lightly pigmented with a tendency to become mucronate, overmature spores deformed and much larger; torus present, narrow; walls not ornamented. Pycnidia not seen.
Chemistry. Spot tests all negative or thallus K+ y, C-, KC-, P+ light yellow like soralia; secondary metabolites, atranorin and zeorin.
Substrate and Ecology. Collected on Acer, Baccharis pilularis, Platanus, Populus, Quercus garryana, Salix and Ulmus in oceanic habitats, at elevations of 0-250 m. Two specimens (Tønsberg 14941, 14973) were collected on a roadside Platanus and Ulmus respectively, concordant with its occurrence in eutrophic habitats in Europe (Mayrhofer and Moberg 2002). The second of these collections was accompanied by R. santae-monicae.
Distribution. In North America the species has a western, oceanic distribution, scattered from southern California to western Alaska. First recorded from North America by Tønsberg (1993). In Europe it is known from southwestern Norway, the British Isles and Austria (Mayrhofer and Moberg 2002).
Notes. The species is characterized by its bluish- or greenish-grey soredia, lighter in colour than the thallus, and by the presence of atranorin and zeorin which is also found in R. degeliana. The latter species is distinguished by its generally lighter thallus colour and its whitish, labriform soralia. The Pachysporaria-type I spores suggest that R. griseosoralifera may be related to R. willeyii, a sorediate eastern species readily distinguished by its lighter coloured thallus and the presence of pannarin.
The apothecial characters above are described from two fertile specimens (Tønsberg 11944, Norway and Tønsberg 15410a, Alaska). Both agree with the type description and that of Tønsberg (1992). The slightly larger spore dimensions reported by Coppins (1989) suggest that some overmature spores may have been included in the measurements. Illustrations accompanying the type description show the same range of spore structure as that found in the material studied here. The only notable feature of the apothecia is the small size of the hypothecium relative to the hymenium also reported by Tønsberg (1992).
Specimens examined. CANADA. BRITISH COLUMBIA. Haida Gwaii (Queen Charlotte Islands), Moresby Island, Bag Inlet, T. Tønsberg 32376 (BG). U.S.A. ALASKA. Juneau Borough, Douglas Island, T. Tønsberg 16141; Kodiak Island Borough, Buskin Lake, T. Tønsberg 15212; S Kodiak, T. Tønsberg 15410a; Yakutat Borough, Yakutat Foreland, T. Tønsberg 29938. CALIFORNIA. Santa Barbara Co., San Miguel Island, T. Tønsberg 25430 (all BG); Sonoma Co., Sugar Loaf Ridge State Park, S.C. Tucker 37795 (SBBG). OREGON. Benton Co., Corvallis, T. Tønsberg 14937, 14941 (BG); Paul Dunn Forest, B. McCune 20065 (personal herb.). WASHINGTON. Snohomish Co., Edmonds, T. Tønsberg 14556 (BG).
Selected References. Tønsberg (1992), Fox & Purvis (1992), Giralt et al. (1995), Sheard (1995), Giralt (2001), Mayrhofer & Moberg (2002 p. 103), Sheard (2004).
Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.
Thallus: crustose, thin, areoles scattered or contiguous, up to 0.4-0.6 mm wide, plane to slightly convex, or forming a continuous crust over bryophytes surface: light to dark gray, often with a bluish or brownish tinge, dull; margin: indeterminate; prothallus: lacking; areoles rapidly becoming sorediate soredia: usually bluish or greenish gray, lighter than thallus, in discrete soralia the same size as areoles Apothecia: not reported from North America, elsewhere, rare, sessile, 0.3-0.4 mm in diam. disc: usually poriform thalline margin: prominent, sometimes sorediate asci: clavate, 8-spored ascospores: brown, 1-septate, ellipsoid, type A development, Pachysporaria-type, (18-)20.5-23.5(26) x (9.5-)11-13(-15) µm Pycnidia: not seen Spot tests: thallus and soralia K+ yellow, C-, KC-, P+ faint yellow Secondary metabolites: atranorin and zeorin. Substrate and ecology: on bark and mosses, collected on Acer sp., Baccharis pilularis, and Quercus garryana, in humid habitats World distribution: southwestern Norway, British Isles, central Europe and oceanic western North America Sonoran distribution: known only from San Miguel Island, Santa Barbara County, California, its southernmost North American locality. Notes: Rinodina griseosoralifera is characterized by its discrete blue-gray soralia, and presence of atranorin and zeorin. It is unlikely to be confused with other Rinodina species possessing vegetative propagules in the study area. One of a number of vegetatively reproducing species with transatlantic disjunct distributions discussed by Sheard (1995) and now shown to have a wider latitudinal distribution in western North America.