MB#484375

Type. U.S.A. CALIFORNIA. Santa Clara Co., Mount Hamilton Range, San Antonio Valley, on bark of Quercus lobata with R. santae-monicae, 4 August 1968, Alice Howard s.n. (UC - holotype!).

Exsiccatae. Weber Lich. Exs. COLO 206 (M, UC as R. archaea).

Description. Thallus crustose, thin, verrucose; verrucae discrete, to 0.15-0.20 mm wide, or areolate; areoles contiguous, irregular, rugose, to 0.40-0.60 mm wide; surface grey to dark grey-brown, matt; margin indeterminate; prothallus lacking; vegetative propagules absent.  Apothecia narrowly attached, frequent, often contiguous, to 0.40-0.70 mm in diam.; disc dark brown to black, plane to slightly convex; thalline margin prominent, concolourous with thallus, or in dark thalli often with light grey, flaking scales of epinecral layer, ca. 0.10 mm wide, entire, persistent, or becoming partially excluded; excipular ring absent.  Apothecial Anatomy. Thalline exciple 60-70(-85) µm wide laterally; cortex 10-20 µm wide; epinecral layer usually present, ca. 5 µm wide; crystals absent in cortex and medulla; cortical cells to 3.5-8.0 µm wide, pigmented or not; algal cells to 11.0-18.5 µm long; thalline exciple 60-100 µm below; cortex expanded to 15-30 µm, cellular; proper exciple hyaline, 10-20 µm wide laterally, expanding to 20-30 µm at periphery; hypothecium hyaline, (30-) 50-80 µm deep; hymenium:100-140 µm high, not inspersed; paraphyses 2.0-3.0 µm wide, sometimes conglutinate, with apices to 4.0-5.5 µm wide, moderately pigmented, forming a brown epihymenium of varying darkness; asci 60-80 x 20-25 µm. Ascospores 8/ascus, Type A, rarely Type B development, often asynchronous, Dirinaria-type, (17.5-)22.0-23.0(-27.5) x (9.0-)10.5-11.0(-13.0) µm, average l/b ratio 2.0-2.1, lumina angular (Physcia-like) at first, becoming rounded, cells retaining thick apical walls, young spores sometimes inflated at septum, more so in KOH, overmature spores with spherical, often refractive lumina, sometimes submucronate; torus absent; wall very lightly ornamented, ornamentation not visible in old, darkly pigmented spores. Pycnidia immersed in verrucae, ostioles hyaline; conidiophores Type VI; conidia bacilliform, 4.5-5.5 x ca. 1.0 µm.

Chemistry. Spot tests negative; secondary metabolites not detected.

Substrate and Ecology. Rinodina endospora usually occurs as small thalli, mainly on twigs and small branches of deciduous trees and shrubs. Collected on Abies magnifica, Cornus nutallii, Populus trichocarpa, Quercus agrifolia, Q. kelloggii, Q. lobata, Rhamnus, Salix and Umbellularia californica. The species has been recorded with R. badiexcipula, R. capensis, R. freyi, R. polyspora, R. pyrina, R. laevigata and R. santae-monicae at elevations of 405-1,675 m.

Distribution. Endemic to California, distributed along the Coastal Ranges and in the Sierra Nevada and therefore belonging to the Californian floristic element.

Notes. Rinodina endospora is characterized by its Dirinaria-type spores with frequent asynchronous development and light grey, flaking scales of the epinecral layer on the apothecial margins which, however, are only obvious in dark coloured thalli. These spores are easily mistaken for those of the Physcia-type because of their lumina shape prior to maturity and the fact that septal swelling is mostly limited to immature spores. Further features of this species are that the spore lumina are almost perfectly spherical at maturity and the endospore wall becomes refractive when the spores are overmature, giving the appearance of endospores (after which the species is named). This phenomenon sometimes occurs in other species with Dirinaria-type spores. The spores are variable in length with a CV >10%, presumably a result of their asynchronous development.

Specimens with small apothecia might be mistaken for R. laevigata which differs in its possession of Physcia-type spores averaging < 20 µm long. The habit of R. endospora also may be similar to that of R. badiexcipula but is distinguished by the absence of medullary sphaerophorin crystals, the unpigmented proper exciple, smaller spores, and by the lack of a columnar lower cortex. Specimens with dark thalli could possibly be mistaken for R. oregana but that species has massive spores, averaging 30.5 µm long, with very obvious Type B development. The spores of R. endospora are similar to those of R. riparia Sheard which, however, have hyaline apices, are slightly smaller and lack wall ornamentation (Sheard 1998).

Specimens examined [not recorded by Sheard and Mayrhofer (2002)]. U.S.A. CALIFORNIA. Calaveras Co., Arnold, I. Tavares 299 (ABSL, UC); Glenn Co., Plaskett Meadows, 2002, S.C. Tucker 37708; Lake Co., 'The Slides', S.C. Tucker 35375c; Clear Lake, S.C. Tucker 28807 (all SBBG); Los Angeles Co., San Gabriel Wilderness, B.D. Ryan 26466, 26467 (ASU); Mariposa Co., Yosemite Valley, 1900, H.E. Hasse (FH); San Diego Co., Barona Ranch Indian Reservation, P. van Den Boom 25213 (personal herb.); Santa Barbara Co., Coldspring Canyon, S.C. Tucker 10967 (SBBG); Siskijou Co., 2.5 mi SW Etna, B.D. Ryan 24868, 24869; 2.5 mi SE Etna, B.D. Ryan 24874; 3 mi NE Seiad Valley, B.D. Ryan 25685, 25692; 6 mi W Scott Bar, B.D. Ryan 24990 (all ASU); Shasta River, B. McCune 18870 (personal herb.); Sonoma Co., Sugar Loaf Ridge, S.C. Tucker 37789 (SBBG); Tulare Co., Sequoia Nat. Park, C.M. Wetmore 50366, 50702 (MIN); Ventura Co., 7 mi N Santa Paula, I. Tavares 1279a (UC).

References. Sheard & Mayrhofer (2002 Fig. 10), 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, consisting of discrete verrucae, up to 0.15-0.2 mm wide, or of contiguous, irregular, rugose areoles, up to 0.4-0.6 mm wide surface: gray to dark gray-brown, dull; margin: indeterminate; prothallus: lacking; vegetative propagules: absent Apothecia: sessile, frequent, often contiguous, up to 0.4-0.7 mm in diam. disc: dark brown to black, plane to slightly convex thalline margin: prominent, concolorous with thallus, or in dark thalli usually with light gray, flaking scales of epinecral layer, c. 0.1 mm wide, entire, persistent, or becoming partially excluded; excipular ring: absent thalline exciple: 60-70(-85) µm wide laterally; cortex: 10-20 µm wide; epinecral layer: usually present, c. 5 µm wide; cortical cells: up to 3.5-8 µm wide, pigmented or not; algal cells: up to 11-18.5 µm in diam.; thalline exciple: 60-100 µm below; cortex: expanded to 15-30 µm, cellular proper exciple: hyaline, 10-20 µm wide laterally, expanding up to 20-30 µm at periphery hymenium: 100-140 µm tall, paraphyses: 2-3 µm wide, sometimes conglutinate, with apices up to 4-5.5 µm wide, moderately pigmented, forming a brown epihymenium of varying darkness; hypothecium: hyaline, (30-)50-80 µm thick asci: clavate, 60-80 x 20-25 µm, 8-spored ascospores: brown, 1-septate, ellipsoid, type A or B development, Dirinaria-type, (17.5-)22-23(-27.5) x (9-)10.5-11(-13) µm, lumina angular (Physcia-like) at first, becoming rounded but retaining thick apical walls, young spores may be inflated at septum, most spores inflated in K, mature spores sometimes submucronate, endospore wall becoming pigmented (and sometimes refractive) in overmature spores; torus: absent; walls: very lightly ornamented, ornamentation not visible in old, darkly pigmented spores Pycnidia: immersed in verrucae, ostioles hyaline; conidiophores: Type VI conidia: bacilliform, 4.5-5.5 x c. 1 µm Spot tests: all negative Secondary metabolites: none detected. Substrate and ecology: on twigs and small branches of deciduous trees and shrubs World distribution: endemic to California, distributed along the coastal ranges and Sierra Nevada Sonoran distribution: Santa Cruz Island and San Gabriel Mountains, from sea level to 1475 m. Notes: Specimens with small apothecia might be mistaken for R. laevigata that species, however, has Physcia-type spores less than 20 µm long. Its habit also may be similar to R. badiexcipula but is easily distinguished by the absence of medullary sphaerophorin crystals, the unpigmented proper exciple, smaller spores, and by the lack of a columnar lower cortex.