Taxonomic Note. The description below, copied from Sheard (2010), refers to R. degeliana, which, according to Resl. et al. (2016), is a synonym of R. subparieta.
Rinodina degeliana Coppins, Lichenologist 15: 147 (1983). Type. SWEDEN. LULE LAPPMARK. Kvikkjokk parish, south east slope of Nammatj, 66 56', 17 42'E, alt 520m, on Salix bark in Picea woodlands, 28/7/1977, B.J. Coppins 6238 and L. Tibell (E ‑ holotype, UPS ‑ isotype).
Description.Thallus thin, typically light grey but sometimes ochraceous, usually composed of discrete areoles; to ca. 0.80 mm wide, sometimes merging to become continuous; surface plane, shining; margin indeterminate; prothallus absent; vegetative propagules present; becoming sorediate from underside of areole margins to form labriform soralia, subsequently spreading to the thallus surface, whitish (lighter than nonsorediate parts of thallus). Apothecia frequently absent, narrowly attached, rarely contiguous, to 0.50‑0.90 mm in diam.; disc dark brown or typically black, persistently plane; thalline margin concolourous with thallus, entire, 0.05‑0.10 mm wide, persistent, or thalline margin incomplete; excipular ring present when thalline margin incomplete, raised, concolourous with disc, ca. 0.05 mm wide. Apothecial Anatomy. Thalline exciple 60‑100 µm wide laterally; cortex 10‑20 µm wide laterally, sometimes with epinecral layer ca. 10 µm wide; crystals in cortex, absent in medulla; cortical cells to ca. 5.5 µm wide, not pigmented; algal cells to 10.0‑11.5 µm long; thalline exciple expanding to 65‑110 µm below; cortex then 30‑70 µm deep; proper exciple hyaline, ca. 10 µm wide laterally, to 20‑30 µm above, considerably wider when thalline exciple absent; hypothecium colourless, 70‑140 µm deep; hymenium 100‑110 µm high, not inspersed; paraphyses ca. 2.5 µm wide, conglutinate with apices to 4.0‑4.5 µm in diam., hardly pigmented but immersed in a diffuse pigment producing a light red‑brown epihymenium; asci 75-80 x 15-20 µm (after Coppins 1983). Ascospores 8/ascus, developmental type A, Physcia‑type, (5.0-)18.5-19.5(-23.0) x (8.5-)10.0‑11.0(-13.0) µm, average l/b ratio 1.7-1.9, canals only evident in young spores, lumina quickly becoming rounded but mostly retaining thick apical walls except when over mature; torus prominent; wall usually ornamented (x1250). Pycnidia not observed.
Chemistry. Spot tests, K+ yellow, C‑, P+ deep lemon‑yellow, medulla and soredia; secondary metabolites, atranorin and zeorin (Tønsberg 1992).
Substrate and Ecology. Corticolous on Abies grandis, Acer glabra, A. rubrum, Alnus rubra, Betula, Picea rubens, Populus P. tremuloides, Salix and Thuja, from sea level to 860 m. It has been collected with R. adirondackii, R. efflorescens, R. excrescens in the east and R. marysvillensis in the west.
Distribution.Rinodina degeliana has a Pacific and north Atlantic disjunct distribution (Sheard 1995). In North America it occurs in the Great Lakes-St. Lawrence region in the east and with an oceanic, Vancouverian type of distribution from northern California to Alaska in the west. Reported from North America for the first time by Wong and Brodo (1992). Known from Scandinavia, Scotland and Austria in Europe (Mayrhofer & Moberg 2002).
Notes. Rinodina degeliana is characterized by its light grey thalli, whitish, labriform soralia in early development, and the presence of atranorin. Coppins (1983) provides a very complete description of R. degeliana from its type locality in northern Sweden which agrees well with the specimens seen from North America. The spore wall may not be as heavily ornamented in North America. The spore lumina of the Physcia-type spores become rounded and over mature spores are reminiscent of the Milvina‑type. A relatively large number of spores become very broad and deformed while others develop without a septum.
Rinodina degeliana and R. efflorescens are typically poorly fertile or sterile and frequently occur together as in the type locality of R. degeliana and a number of eastern North American localities. Both species have similar disjunct distributions in humid regions of the northwest and northeast of the continent, and western Europe (Sheard 1995). Rinodina efflorescens is distinguished by the presence of pannarin but may have similar light grey thalli. However, the whitish soralia of R. degeliana contrast with the grey colour of the rest of the thallus, whereas there is less distinction between the colour of the soredia and thallus in light grey forms of R. efflorescens. Many collections of the latter species from Scotland (E) and North America have darker thalli with contrasting greenish soredia, states that have never been observed in R. degeliana.
Rinodina griseosoralifera is also characterized by the presence of atranorin and zeorin but is distinguished its bluish- or greenish-grey soralia over large areas of the thallus, and by its Pachysporaria-type spores. Other sorediate Rinodina species in North America have different chemistries.
Specimens examined. CANADA. BRITISH COLUMBIA. Bralorne, T. Tønsberg 12821, 12826; Brandywine Falls, T. Tønsberg 12750; Cheakamus River, T. Tønsberg 12934; Saltspring Island, T. Tønsberg 12102 (all BG); Wells Gray Prov. Park, Blackwater Creek, T. Goward 1191 (personal herb.). NEW BRUNSWICK. Kouchibouguac Nat. Park, E. Serousiaux 10195; Bruce Co., Sky Lake, P.Y. Wong 2141; Gloucester Co., P.Y. Wong 4525 (all CANL). QUEBEC. Abiti‑Ouest Co., S Lac Chicobi, I.M. Brodo 16942 (CANL, GZU); Gatineau Co., 7.5 km W Poltimore, I.M. Brodo 24969a (SASK); 24964 (CANL). U.S.A. ALASKA. N of Dyea, T. Tønsberg 32903; Chiklat Peninsula, T. Tønsberg 33279 ; Kodiak Island, S Monashka Bay, T. Tønsberg 15650. CALIFORNIA. Del Norte Co., Elk Creek, T. Tønsberg 14713b (all BG). MAINE. Aroostook Co., Nixon Siding, S. Selva 3410; Piscataquic Co., Pinkham Road, S. Selva 3405 (both personal herb.); Washington Co., Trail to Lead Mountain, B. Hodkinson 163 (WILLI). MICHIGAN. Baraga, Co., 5 mi NE Sidnaw, R.C. Harris 8096 (MSC); Cheboygan Co., W Hebron Mail road, R.C. Harris 9398 (UMBS); Emmet Co., Larks Lake, R.C. Harris 8872 (MICH). NEW YORK. Warren Co., Riparius Village, T. Tønsberg 17832. OREGON. Hood River Co., N Pollalie Creek Bridge, T. Tønsberg 29119. WASHINGTON. Kittitas Co., 23 km SSE Snoqualmi Pass, T. Tønsberg 25910; Whatcom Co., Diablo Lake Bridge, T. Tønsberg 18548 (all BG). WISCONSIN. Vilas Co., Eagle River, J.W. Thomson 2130 (WIS).
Selected References. Tønsberg (1992 Fig. 113), Wong & Brodo (1992), Giralt et al. (1995), Sheard (1995), Mayrhofer & Moberg (2002 p. 102), Thomson (2003).
Resl, P., H. Mayrhofer, S. R. Clayden, T. Spribille, G. Thor, T. Tönsberg & J. W. Sheard. (2016) Morphological, chemical and species delimitation analyses provide new taxonomic insights into two groups of Rinodina. Lichenologist48(5): 469-488.