Type. U.S.A. CALIFORNIA. Sonoma Co., about 3 mi (5.8 km) E on Spring Mountain road from Calistoga-Santa Rosa road. Narrow canyon with Sequoia, Lithocarpus, Quercus agrifolia. On twigs of Q. agrifolia, 24 November, 1962, Isabelle Tavares 1323 with Phyllis Roskin (UC - holotype!, isotypes!).
Description.Thallus thin, light or dark grey, continuous or rimose; surface plane or minutely rugose, matt; margin usually indeterminate; prothallus lacking; vegetative propagules absent. Apothecia narrowly attached, frequent, often contiguous, sometimes angular by compression, to 0.30-0.70 mm in diam.; disc black, plane, occasionally becoming convex; thalline margin concolourous with thallus, 0.05-0.10 mm wide, entire, persistent or sometimes excluded; excipular ring absent. Apothecial Anatomy. Thalline exciple 45-70 µm wide laterally; cortex 5-10 µm wide; epinecral layer absent; crystals in cortex, absent in medulla; cortical cells to 4.5-5.0 µm wide, rarely pigmented; algal cells to 9.0-15.5(-17.0) µm long; thalline exciple 60-80 µm wide below; cortex 10-20(-30) µm deep, hyphae intricate; proper exciple hyaline, (5-)10-15 µm wide, expanding to 10-20 µm at periphery; hypothecium hyaline, 50-80 µm deep; hymenium 80-100 µm high, not inspersed; paraphyses 2.0-2.5 µm wide, often conglutinate, with apices to 4.0-5.0 µm, heavily pigmented, forming a dark brown or reddish brown epihymenium; asci 60-70 x 15-20 µm. Ascospores 8/ascus, Type A development, Dirinaria-type, (15.5-)17.5-18.5(-20.5) x (8.5-) 9.5-10.5(-12.0) µm, average l/b ratio 1.7-1.8, some spores dilated at septum when young, more so in KOH, lumina angular and Physcia-like at first, becoming rounded, usually retaining thick apical walls but sometimes almost filling the cells; finally developing pigmented endospore wall in overmature spores; torus narrow, only in mature spores (best seen in KOH); walls lightly ornamented. Pycnidia immersed in thallus, ostioles becoming darkly pigmented; conidiophores type V; conidia bacilliform, 3.0-4.0 x ca. 1.0 µm.
Substrate and Ecology. Rinodina californiensis occurs on the following deciduous trees, Adenstoma fasciculatum, Ceanothus, Cercis occidentalis, Quercus agrifolia, Q. douglasii, Q. lobata and Q. wislizenii, most frequently on twigs but also on wood. The species has often been collected with R. santae-monicae, also with R. badiexcipula, R. capensis, R. laevigata, and R. marysvillensis.
Distribution. A North American endemic belonging to the Californian floristic element. Found in the Coastal Ranges, north to British Columbia, south to Baja California, and also in the Sierra Nevada where it is rare and occurs to 1 340 m, its highest recorded elevation.
Notes.Rinodina californiensis typically does not become areolate but nevertheless is similar in external appearance to a diminutive R. capensis, which has larger, Physcia-type spores with more angular lumina, and more persistently thickened apical walls, in addition to the massive, columnar apothecial lower cortex. Rinodina santae-monicae is distinguished by lacking atranorin, possessing a dark brown, heavily pigmented epihymenium, a frequently prominent excipular ring, and sometimes an incompletely formed thalline margin. Rinodina santae-monicae is another species that may also become consorediate, particularly in the northern part of its range. Rinodina californiensis is perhaps most closely related to, and might be mistaken for R. marysvillensis in the absence of disc pruina, but the latter species is distinguished by its more prominent apothecial margin, columnar lower cortex, and presence of epihymenial pannarin.
The spores of R. californiensis belong to the Dirinaria-type although the Type B development usually associated with this spore type (Giralt & Mayrhofer 1995) has not been observed. The spores possess other characters usually associated with Dirinaria-type spores such as the presence of a septal disc prior to differentiation of a torus, swelling at the septum in young spores which is emphasized by treatment with KOH, and pigmentation of the endospore wall after maturity. The separation of wall layers in the region of the septal swelling also is very characteristic of the Dirinaria-spore type. There appear to be two colour forms of R. californiensis, one light grey, the other dark grey which is associated with fewer atranorin crystals when viewed under polarized light and which may sometimes be restricted to the lower cortex of the apothecial margin.
Specimens examined [and not previously recorded by Mayrhofer and Sheard (2002)]. CANADA. BRITISH COLUMBIA. Marble Canyon Prov. Park, 1994, R. Rosentreter 8723 (SASK). U.S.A. CALIFORNIA. Contra Costa Co., Tilden Regional Park, 1968, V. Duran (UC); Lake Co., 'The Slides', S.C. Tucker 35375C (SBBG); Los Angeles Co., Catalina Island, J.W. Sheard 5001, 5007a, 5011 (SASK); Monterey Co., Carmel Valley, I. Tavares 875, 2117, 2128, 2209a; Monterey Co., Jamesburg, I. Tavares 63C (all UC); Santa Lucia Range, B.D. Ryan 11217 (ASU); W Greenfield, S.C. Tucker 34599, 34600 (SBBG); Napa Co., 2 mi S Calistoga, P.C. Hutchinson 898A (UC); 2 mi W Moscowitz Corner, S.C. Tucker 37440 (SBBG); San Diego Co., Eagle Crag, B.D. Ryan 25884; San Luis Obispo Co., 3 km ESE Pozo, L. Ross 240 (both ASU); Huasna River valley, C.C. Bratt 4974; Los Osos, S.C. Tucker 35085 (both SBBG); Santa Barbara Co., Santa Cruz Island, J.W. Sheard 5130b (SASK); S.C. Tucker 35685B (SBBG); Santa Cruz Co., Bonny Doon, I. Tavares 2079 (UC); Siskiyou Co., 3 mi NE Seiad Valley, B.D. Ryan 25696 (ASU); Sonoma Co., N Guerneville, S.C. Tucker 31753 (SBBG); Yolo Co., Winters, 1975, W.A. Weber (COLO). OREGON. Benton Co., Corvallis, B. McCune 20056; 2003, D. Campanella (both McCune personal herb.).
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 or rimose, plane or minutely rugose surface: light or dark gray, dull; margin: usually indeterminate; prothallus: lacking; vegetative propagules: absent Apothecia: sessile, frequent, often contiguous, sometimes angular by compression, up to 0.3-0.7 mm in diam. disc: black, plane, occasionally becoming convex thalline margin: concolorous with thallus, 0.05-0.1 mm wide, entire, persistent or sometimes excluded; excipular ring: absent thalline exciple: 45-70 µm wide laterally; cortex: 5-10 µm wide; cells: up to 4.5-5 µm wide, rarely pigmented; algal cells: up to 9-15.5(-17) µm in diam.; thalline exciple: 60-80 µm wide below; cortex: 10-20(-30) µm thick, hyphae intricate proper exciple: hyaline, (5-)10-15 µm wide, expanding to 10-20 µm at periphery hymenium: 80-100 µm tall; paraphyses: 2-2.5 µm wide, often conglutinate, with apices up to 4-5 µm, heavily pigmented, forming a dark brown or reddish brown epihymenium; hypothecium: hyaline, 50-80 µm thick asci: clavate, 60-70 x 15-20 µm, 8-spored ascospores: brown, 1-septate, broadly ellipsoid, type A development, Dirinaria-type, (15.5-)17.5-18.5(-20.5) x (8.5-)9.5-10.5(-12) µm, some spores dilated at septum when young, more so in K, lumina angular, Physcia-like at first, becoming rounded, usually retaining thick apical walls but sometimes almost filling the cells; finally developing pigmented endospore wall in overmature spores; torus: narrow, only in mature spores (best seen in K); walls: lightly ornamented Pycnidia: immersed in thallus, ostioles becoming darkly pigmented; conidiophores: type-V conidia: bacilliform, 3-4 x c. 1 µm Spot tests: K+ yellow, C-, KC-, P- or P+ faint yellow Secondary metabolites: atranorin in cortex. Substrate and ecology: on deciduous trees, most frequently on twigs, also on wood; frequently collected with R. santae-monicae but also with R. badiexcipula, R. capensis, R. laevigata, and R. marysvillensis World distribution: a North American endemic belonging to the Californian floristic element along the coastal ranges, north to Saltspring Island, British Columbia, south to Baja California, rare in the Sierra Nevada where it occurs to 1340 m, its highest recorded elevation Sonoran distribution: southern California, and south to El Rosario, Baja California. Notes: Rinodina californiensis typically does not become areolate, but nevertheless is similar in external appearance to a diminutive R. capensis, that has larger, Physcia-type spores with more angular lumina, and more persistently thickened apical walls, in addition to the massive, columnar apothecial lower cortex. Rinodina santa-monicae is distinguished by lacking atranorin, possessing a dark brown, heavily pigmented epihymenium, a frequently prominent excipular ring, and an incompletely formed thalline margin. Rinodina marysvillensis might be mistaken for R. californiensis in the absence of disc pruina but is distinguished by its more prominent apothecial margin, columnar lower cortex, and presence of pannarin in the epihymenium.