Description.Thallus thin, light grey to dark grey, continuous, rimose or rarely areolate; areoles to ca. 0.50 mm wide; surface rugose, matt; margin indeterminate; prothallus lacking; vegetative propagules absent. Apothecia narrowly attached, frequent, contiguous or not, to 0.60-0.70 mm in diam.; disc brown to black, usually pruinose, persistently plane except some of largest and oldest; thalline margin concolourous with thallus, 0.05-0.10 mm wide, very prominent in young apothecia, entire and persistent; excipular ring absent. Apothecial Anatomy. Thalline exciple 60-80 µm wide laterally; cortex 10-15 µm; epinecral layer absent; crystals present in cortex, absent in medulla; cortical cells to ca. 4.5 µm wide; algal cells to 10.0-13.0 µm long; thalline exciple 60-90 µm below; cortex 25-40 µm, columnar; proper exciple hyaline, 10-15 µm wide laterally, expanded to 10-30 µm at periphery; hypothecium hyaline, 50-70 µm deep; hymenium 70-100 µm high, not inspersed; paraphyses 1.5-2.0 µm wide, not conglutinate, with apices to 3.5-4.5 µm wide, hardly pigmented, immersed in dispersed pigment forming a light red‑brown epihymenium, typically with crystals on surface, P+ developing red crystals; asci 50-70 x 18-23 µm. Ascospores 8/ascus, Type A development, Dirinaria-type, (15.0-)17.5-18.5(-21.0) x (7.5-)9.0-10.0(-11.5) µm, average l/b ratio 1.8-2.0, lumina angular at first (Physcia-like), becoming irregularly rounded but mostly retaining thick apical walls, sometimes inflated at septum, particularly young spores, more so in KOH; torus absent; walls lightly ornamented. Pycnidia not seen.
Chemistry. Spot tests, K+ yellow, C-, P‑ or P+ faint yellow; secondary metabolites, atranorin in cortex; typically with pannarin on surface of epihymenium and adjacent proper exciple, P+ red needles (in alcoholic P).
Substrate and Ecology. Found on twigs and small branches of deciduous and coniferous trees and shrubs at elevations of 300-600 m. Found on Acer glabra, Alnus rhombifolia, A. rubra, Bacchus pilularis, Betula, Quercus agrifolia, Q. garryana, Pinus muricata, Pseudotsuga menziesii. It has been collected with R. californiensis, R. capensis, R. degeliana, R. hallii, R. laevigata and R. santae-monicae.
Distribution. A western North American endemic, with a Californian distribution and northern outliers in the coastal British Columbia-Washington state area. First recorded for Canada by Noble (1978, 1982).
Notes.Rinodina marysvillensis is characterized by its grey thallus, atranorin containing cortex, apothecia with prominent margins, and typically pruinose discs due to the presence of pannarin crystals on the surface of the epihymenium. Rinodina aurantiaca from mainly higher elevations in the Cascades and Rocky Mountains also has pannarin but within the epihymenium rather than on its surface. That species also has a similar thallus morphology and chemistry, but has significantly larger Physcia-type spores. It also has less prominent apothecial margins and the discs often become slightly convex. Rinodina marysvillensis is probably more closely related to R. californiensis than to R. aurantiaca because the spores of both species belong to the Dirinaria-type, although both lack the typical Type B development of this spore type. The spores of R. californiensis cannot be distinguished by length but they are mostly more broadly ellipsoid. The very prominent thalline margins, particularly of young apothecia, are not found in R. californiensis. The two species are found together in some duplicates of Lich. Exs. COLO 474.
The type, as Magnusson (1953) has noted, is not well developed but other material indicates that the species is not as closely related to R. excrescens (= R. marysvillensis var. thujae) as he supposed. Although that taxon also has pannarin in the epihymenium, it is also present in the thallus. Rinodinaexcrescens, a species of eastern North America, further differs in its distinctive thallus composed of discrete, convex and sometimes blastidiate verrucae, often crenulate apothecial margin and Physcia-type spores.
Specimens examined. CANADA. BRITISH COLUMBIA. Sidney, Vancouver Island, 1912, J. Macoun (FH, UBC); Victoria, W.J. Noble 3616 (SASK). U.S.A. CALIFORNIA. Amador Co., between Sutter Creek and Volcano, 1975, W.A. Weber (COLO, UAC); Contra Costa Co., Tilden Reg. Park, 1968, V. Duran; 1968, R. Russo; Glenn Co., Elk Creek, I. Tavares 1432a; Marin Co., I. Tavares 1037; Stinson Beach, I. Tavares 1064 (all UC); Napa Co., NNE Wooden Valley, S.C. Tucker 11008 (LSU); St. Helena, S.C. Tucker 6126 (SBBG); San Francisco Co., Lands End, I.M. Brodo 20481 (CANL); San Louis Obispo Co., Point Bouchon, S.C. Tucker 34247 (SBBG); Baywood Park, R.E. Riefner 9049 (IRVC); San Mateo Co., Cahill Ridge, W. Jordan 635 (WIS); Santa Barbara Co., Point Sal Ridge, S.C. Tucker 13718 (SBBG); Santa Cruz Island, J.W. Sheard 5105, 5124a (SASK); S.C. Tucker 35833 (SBBG); Santa Rosa Island, J.W. Sheard 5038a, 5047, 5049 (SASK); Santa Cruz Co., Bonny Doon, I. Tavares 2049 (UC). OREGON. Josephine Co., 10 mi N Grant's Pass, L.H. Pike 56962 (PMAE); 1973, L.H. Pike (BM); Lincoln Co., Ona Beach State Park, B. McCune 26278 (personal herb.). WASHINGTON. San Juan Co., San Juan Island, I.M. Brodo 15525 (CANL); Snohomish Co., Marysville, 1927, J.M. Grant (UPS).
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, continuous, rimose or rarely areolate, areoles up to c. 0.5 mm wide, rugose surface: light gray to dark gray, dull; margin: thallus indeterminate; prothallus: lacking; vegetative propagules: absent Apothecia: sessile, frequent, contiguous or not, up to 0.6-0.7 mm in diam. disc: brown to black, usually pruinose, persistently plane except for some of largest and oldest apothecia thalline margin: concolorous with thallus, 0.05-0.1 mm wide, prominent in young apothecia, entire and persistent thalline exciple: 60-80 µm wide laterally; cortex: 10-15 µm; cells: up to c. 4.5 µm wide; algal cells: up to 10-13 µm in diam.; thalline exciple: 60-90 µm below; cortex: 2540 µm, columnar; excipular ring: absent proper exciple: hyaline, 10-15 µm wide laterally, expanded to 10-30 µm at periphery hymenium: 70-100 µm tall; paraphyses: 1.5-2 µm wide, not conglutinate, with apices up to 3.5-4.5 µm wide, hardly pigmented, immersed in dispersed pigment forming a light red-brown epihymenium, typically with surficial crystals, P+, developing red crystals; hypothecium: hyaline, 50-70 µm thick asci: clavate, 50-70 x 1823 µm, 8-spored ascospores: brown, 1-septate, ellipsoid, type A development, Dirinaria-type, (15-)17.5-18.5(-21) x (7.5-)9-10(-11.5) µm, lumina angular at first, becoming irregularly rounded but retaining thick apical walls, sometimes narrowly inflated at septum with K, endospore wall becoming pigmented in overmature spores; torus: hyaline, developing late; walls: lightly ornamented Pycnidia: not seen Spot tests: K+ yellow, C-, KC-, P- or P+ faint yellow Secondary metabolites: atranorin in cortex; typically with pannarin on surface of disc and adjacent proper exciple. Substrate and ecology: on twigs and small branches of deciduous and coniferous trees and shrubs at low elevations World distribution: a western North American endemic with an oceanic distribution in the coastal ranges from California to southern British Columbia Sonoran distribution: Santa Barbara Co., California, the southern limit of its range. Notes: Rinodina marysvillensis is characterized by its gray, atranorin-containing thallus, apothecia with prominent margins, and typically pruinose discs due to the presence of pannarin crystals on the surface of the epihymenium. Rinodina aurantiaca from mainly higher elevations in the Cascades and Rocky Mountains also has pannarin associated with the epihymenium but within the epihymenium rather than on its surface. This species also has a similar thallus morphology and chemistry, but has significantly larger Physcia-type spores. It also has less prominent apothecial margins and the discs may become convex.