Type. NORWAY. HORDALAND. Bergen, Store Milde, Fana Folkehøgskole, alt. 20-40 m, on mossy trunk of Prunus avium in an old garden, 14 October 1988, T. Tønsberg 11375 (BG - holotype, SASK - isotype!).
Description.Thallus thin, yellow, or greenish or brownish yellow, areolate; areoles scattered, sometimes becoming irregularly elongate, to 0.30 mm long; surface convex, quickly becoming plane, matt; margin indeterminate; prothallus absent; vegetative propagules present; areole surfaces dissolving into soralia concolourous with thallus, irregular in outline, flat to slightly convex, 0.30-0.80 mm wide; soredia loosely arranged, farinose, 20-30(-40) µm in diam. (This account of the vegetative characters is mainly summarized from Tønsberg, 1992). Apothecia broadly attached, rare, mostly broadly attached, with pore-like opening when immature; mature apothecia narrowly attached, sometimes contiguous, to ca. 0.65 mm in diam.; disc brown, persistently plane; thalline margin concolourous with thallus, entire, ca. 0.10 mm wide, persistent; disc brown; excipular ring present, confluent. ApothecialAnatomy. Thalline exciple 60-70 µm wide; cortex ca. 10 µm wide; epinecral layer absent; crystals in cortex and medulla; cortical cells to ca. 4.5 µm wide, not pigmented; algal cells to ca. 12.0 µm long; basal thalline exciple 50-60 deep; cortex 20-25 µm deep, intricate; proper exciple ca. 15 µm wide, expanding to ca. 30 µm above, hyaline; hypothecium hyaline, ca. 80 µm deep; hymenium 130-140 µm high, not inspersed; paraphyses ca. 2.0 µm wide, not conglutinate with apices to ca. 3.5 µm wide, lightly pigmented, forming a light to orange-brown epihymenium; asci mostly immature, ca. 105 x 25 µm when mature. Ascospores 8/ascus, Type A development, Pachysporaria-type I, (21.5-) 25.0-27.0(-30.0) x (11.5-)14.5-16.0(-19.0) µm, average l/b ratio 1.6-1.8, lumina rounded, mostly with satellite apical lumina, torus narrow; walls not ornamented. Pycnidia very rare; conidia bacilliform, 4.0-5.0 x ca. 1.0 µm.
Substrate and Ecology. Alaskan specimens on Alnus shrub and deciduous park tree, near the ocean (Tønsberg 2002). Californian material was collected on a Quercus branch at an elevation of 600 m, with R. badiexcipula and R. capensis.
Distribution. In North America R. flavosoralifera is known from the Alaskan panhandle (Tønsberg 2002) and California, the latter specimen being a new record for the lower states. The species is an addition to the disjunct vegetatively reproducing species discussed by Sheard (1995). The species is also scattered in the coastal lowlands of southwestern Norway, in Scotland, England and France (Tønsberg 2002) and recently discovered at ca. 1,175 m in the Canary Islands (Tønsberg 37707, BG). The wide separation of the Alaskan and Californian records is remarkable and suggests that it may also occur in intermediate localities. It may be more than coincidence that the only two specimens with mature apothecia and spores are from the southernmost localities recorded for the species, California and the Canary Islands, respectively. This suggests a relatively southern origin for this species which has a north temperate centre of distribution.
Notes.Rinodina flavosoralifera is well characterized by its yellowish areoles and soralia, due to its xanthone content, and by its lack of other secondary substances. Only R. lepida possesses the above characters although it lacks vegetative propagules, possesses thiomelin rather than arthothelin and thiophanic acid, and has tropical affinities. Rinodina flavosoralifera is rarely fertile and then typically with immature poriform apothecia. The above account contains the first detailed characteristics of mature apothecia, the spores belonging to Pachysporaria-type I. Rinodina sheardii also possesses xanthones and the same spore type. However, only the soredia are pigmented, secalonic acid A is the primary constituent and its spores are smaller. Most importantly, R. sheardii has a pigmented hypothecium, an unusual character in the genus. Tønsberg (2002) compared the species with R. griseosoralifera which has the same spore type but has a very different chemistry.
The spore lumina of R. flavosoralifera sometimes appear to be surrounded by oil globules in freshly collected material. These are similar to the globules illustrated by Mayrhofer et al. (1999) for R. dolichospora but immediately adjacent to the lumina rather than within the wall. They clear when Melzer’s reagent is applied to the slide preparation. The apical satellites are connected to the main lumina, at least in some stages of satellite formation.
Specimens examined. U.S.A. ALASKA. Borough of Juneau, Douglas Island N, Tønsberg 16157a; Borough of Sitka, Baranof Island, Sitka, Tønsberg 16368 (BG). CALIFORNIA. Marin Co., Mount Tamalpais Tate Park, Lendemer 5875 (personal herb.).