Description.Thallus thin or rarely thick, light grey, grey- or copper-brown, continuous, rarely becoming subsquamulose; surface plane or more usually rugose, rarely developing raised verrucae, matt; margin indeterminate; prothallus lacking; vegetative propagules absent. Apothecia broadly to somewhat narrowly attached, frequent and often contiguous, to (0.50)0.70-1.10(-1.50) mm in diam.; disc dark brown, more commonly black, sometimes pruinose especially when young, often becoming convex; thalline margin 0.05-1.00 mm wide, entire, often becoming excluded; excipular ring usually present, confluent, broad. Apothecial Anatomy. Thalline exciple (55-)70-100 µm wide laterally; cortex 5-10 µm wide; epinecral layer frequent, 5-10 µm wide; crystals sometimes present in cortex, absent in medulla; cortical cells to 5.0-6.0 µm wide, rarely pigmented, rarely intricate; algal cells to 9.5-19.0 µm long; proper exciple hyaline, (10-)15-30 µm wide laterally, expanding to (25-)40-60(-70) µm at periphery; hypothecium hyaline or light brown in specimens with dark thalli, 80-140 µm deep, often inspersed with oil droplets; hymenium 90-120 µm high, rarely somewhat inspersed; paraphyses 2.0-3.0 µm wide, conglutinate, with apices to 4.5-5.0(-6.0) µm in wide; pigmented light brown, immersed in dispersed pigment to form a red-brown epihymenium; asci 70-90(-100) x (16-)20-31 µm. Ascospores 8/ascus, Type A development, Physcia‑type, (20.5-)24.5-25.5 (-30.0) x (9.5-)11.5-12.5(-14.5) µm, average l/b ratio 2.0-2.2, usually retaining thick apical wall, cells often unequal in size from early development; torus prominent; walls not ornamented. Pycnidia immersed in thallus; conidiophores type I; conidia bacilliform, 4.0-5.0 x ca. 1.0 µm.
Chemistry. Spot tests all negative, or K+ yellow cortex, or K+ violet to purple medulla; secondary metabolites, atranorin in cortex, skyrin or variolaric acid in medulla (for other minor constituents see Mayrhofer & Moberg, 2002).
Substrate and Ecology. On moss and decaying plants in oro-arctic habitats, descending into the subalpine forest zone. Recorded from sea level in the arctic to 4,070 m in Arizona, the southernmost extent of its range in North America. It has occasionally been collected with R. conradii, R. olivaceobrunnea and R. turfacea. The species possibly occupies more mesic habitats than R. turfacea.
Distribution. An oro-arctic species which in North America appears to be relatively common in the western arctic, penetrating southwards down the Rocky Mountains and is abundant, or least well collected, in Colorado. Rinodina mniaraea is also know from the coastal ranges of Washington and Oregon, and also from the Sierra Nevada. The species appears to be less frequent in the High Arctic than either of the other large spored species, R. roscida and R. turfacea. The species is widespread in oro-arctic regions across the northern hemisphere, scattered in more southerly mountains such as the Pyrenees, Alps, Caucasus, central Asia and Himalayas (Mayrhofer and Moberg 2002).
Notes.Rinodina mniaraea is characterized by its apothecia becoming convex and thalline margins becoming excluded, and by its large, Physcia-type spores which frequently have unequally sized cells, a phenomenon otherwise only recorded for R. subminuta in this work and R. arnoldii by Mayrhofer and Sheard (1988). The species has a well developed proper exciple which is usually visible externally as a broad, confluent excipular ring. Rinodina turfacea is distinguished by its persistently plane apothecial discs, persistent, prominent thalline margins, and by the presence of sphaerophorin. Rinodina olivaceobrunnea is characterized by its smaller apothecia and spores. Rinodina mniaraea sometimes possesses pruinose discs and this has caused confusion with R. roscida, a species that is otherwise more similar to R. turfacea in habit but is distinct in its chemistry. The pruinosity is caused by extrusion of hymenial gelatin and not by surface crystals as it is, for example, in R. roscida.
Three chemotypes have been recognized taxonomically, most recently by Mayrhofer & Moberg (2002). The type variety is the most common and is characterized by variolaric acid and lacks accessory substances other than an unidentified triterpenoid. The var. cinnamomea has a yellow to orange medulla (K+ purple, skyrin chemotype) and has four chemotypes within it, three of which may possess variolaric acid and two atranorin. The var. mniaraeiza has a light grey thallus due to the presence of cortical atranorin (K+ yellow, atranorin chemotype) and variolaric acid. The reactive chemotypes are very rare in arctic regions although it is possible that some specimens of var. cinnamomea have been overlooked in the present study. In the western mountains, reactive specimens may be more common in the south. In a sample of 22 localities collected by Imshaug in Colorado (MSC), 18% of specimens belonged to the cinnamomea and 27% to the mniaraeiza chemotypes.
Morphological or anatomical characters to separate the chemical varieties, including spore characters, have been searched for in vain. Occasionally two varieties occur in the same collection or have been collected in the same locality, offering opportunities for comparison, presumably with reduced environmental variation. Significant differences in spore sizes have been found but these are not consistent. For example, a joint collection of the type variety with the atranorin chemotype (Imshaug 10946, MSC) showed the latter to have significantly longer and narrower spores (l/b ratio 2.2 and 2.4, respectively), in contrast to another joint sample (Ryan 30762-a, ASU) in which the spores the atranorin chemotype were significantly smaller. The average spore size for the sampled population of the atranorin chemotype as a whole is smaller than for the other chemotypes. Given that the var. cinnamomea may also contain atranorin (Chemotype D, Mayrhofer and Moberg 2002), and that there is no consistent difference in spore size between the chemotypes, I have not found it possible to recognize the chemical variants as being taxonomically distinct.
Specimens of acid deficient strain examined. CANADA. ALBERTA. 4 mi SE Warden Rock, G.W. Scotter 21695 (WIS); Banff, J. Macoun (CANL); Bare Mountains, W.A. Weber 23484 (COLO); Crypt Lake, G.W. Scotter 10234 (PMAE); Kananaskis Road, C.D. Bird 12706 (CANL); Laggan, 1904, J. Macoun (FH); Lineham Lake, G.W. Scotter 4942 (WIS); Moose Mountain, 1897, J. Macoun (US); Mosquito Creek, R. Rosentreter 2220 (McCune personal herb.); R. Rosentreter 2227; W. Gauger 67 (both MONT); Mount Edith Cavell, W.A. Weber 23339 (COLO); Plateau Mountain, C.D. Bird 10455 (PMAE, WIS); Queen Elizabeth Range, G.W. Scotter 7768 (CANL); Rocky Mountains, 1897, J. Macoun (FH); Simpson's Pass, Sanson (FH); Snow Creek Valley, 1965, K. Beder (CANL, PMAE); Sunwapta River, W.A. Weber 36320 (COLO); opposite Angel Glacier, H.A. Imshaug 6992b (MSC). BRITISH COLUMBIA. Battle Mountain, T. Ahti 14756 (H); Crater Mountain, G.W. Douglas 4742; Fairy Lake, I.M. Brodo 21768, 21829; Hector, 1855, J. Macoun; Kutcho Creek, R. Rosie 393, 551 (all CANL); Mt. Assiniboine, G.W. Scotter 60730 (H); Robb Lake, I.M. Brodo 21934 (CANL); Trophy Mountain, 1994, T. Goward (GZU); I.M. Brodo 27227, 27232; Wokkpash Lake, I.M. Brodo 21561 (all CANL); Yoho Valley, 1904, J. Macoun (FH). MANITOBA. Wapusk Nat. Park, near Owl River trappers cabin, Piercey-Normore 2949a. NEWFOUNDLAND & LABRADOR. Menihek Lake, I.M. Brodo 8880b (CANL,WIS). NORTHWEST TERRITORIES. Artillery Lake, J.W. Thomson 12167; Canoe Lake, 1964, J.W. Thomson 15837; S end Dubwant Lake, J.W. Thomson 14402 (all WIS); Five Hundred Lake, G.W. Scotter 8564e (H); Great Slave Lake, J.W. Thomson 12121 (WIS); McConnell Range, C.D. Bird 32332 (PMAE); Rebecca Falls, W.A. Gould 540 (MIN); Reindeer Station, G.W. Scotter 5922b (H); J.W. Thomson 15504 (WIS); Tigonankweine Range, G.W. Scotter 16348 (WIS); Tuktoyaktuk, G.W. Scotter 6127c (H); Yellowknife, J.W. Thomson 11331 (WIS). NUNAVUT. Clyde Fjord, M.E. Hale 581 (CANL); Coppermine, J.W. Thomson 12476, 12555 (WIS); Frobisher Bay, W.A. Weber 24039 (COLO); Apex, Baffin Island, J.W. Thomson 13294 (WIS). ONTARIO. Kenora Dist., Cape Henrietta Maria, M.W. Neal 20 (CANL). QUEBEC. La Côte-de-Gaspé Co., 1883, J. Macoun (FH). YUKON. Bates Lake, 1975, G.W. Douglas 9287; Carpenter Lake, G.W. Scotter 19137; Goz Lake, G.W. Scotter 19494, 19511, 19519; Hunker Creek, 1902, J. Macoun; Onion Lake, G.W. Douglas 8839 (all CANL); Richardson Mountains, C.D. Bird 30403 (PMAE); Sockeye Lake, G.W. Douglas 5610 (WIS); Stewart Crossing, R. Rosie 169b (CANL); Trout Lake, J.W. Thomson 14884 (WIS); Whitehorse, I.M. Brodo 26402 (CANL). U.S.A. ALASKA. Arakamtchetchene, C. Wright (FH); Arrigetch Creek, D.J. Cooper 284 (WIS); Barrow, A. Fryday 8334 (MSC); Bering Straits, C. Wright (FH); Fielding Lake, J.W. Thomson 18142 (WIS); Mount Eilson, L.A. Viereck 7513; Mount Mckinley, W.A. Weber 7244 (both COLO); Okpilak Lake, J.W. Thomson 6347; Sheep Mountain, J.W. Thomson 17567 (both WIS). ARIZONA. Coconino Co., Grand Canyon Nat. Park, C.M. Wetmore 17174 (MIN); Mount Agassiz, T.H. Nash 18441; Mount Humphries, T.H. Nash 14868 (both ASU); San Francisco Peaks, J.W. Thomson 18598 (WIS); San Francisco Mountains, T.H. Nash 7542 (ASU). CALIFORNIA. Fresno Co., Piute Pass, H.A. Imshaug 18037b (MSC); Mariposa Co., Yosemite Nat. Park, 1966, C.M. Wetmore (MIN). COLORADO. Boulder Co., Albion Village, S. Shushan 3881, 3898 (COLO); Diamond Lake, S. Shushan 452 (BRY); Lake Eldora, S. Shushan 1077 (COLO); Long Lake, F.E. Lutz (NY); W. Kiener 5255 (COLO); 8 mi NW Nederland, S. Shushan 4791 (BRY); Rollins Pass, S. Shushan 25; Tanima Peak, R.A. Anderson 4176; Wild Basin, R.A. Anderson 1585, 3834 (all COLO); Chaffee Co., Cottonwood Pass, H.A. Imshaug 11710 (MSC); St. Elmo, T.S. Brandegee (FH); Chaffee/Gunnison Cos., Lake Pass, H.A. Imshaug 11775, 11786, 11826 (MSC); Clear Creek Co., James Peak, 1921, C.C. Plitt (MICH); Mount Evans, H.A. Imshaug 11064 (MSC); Mount Evans, S. Shushan 4699; R.A. Anderson 3910 (both COLO); H.A. Imshaug 11174 (MSC); Squaw Mountain Summit, R.A. Anderson (GZU); Custer Co., S Colony Basin, W. Kiener 10307; Eagle Co., 16 mi S Eagle, 1977, D.L. Buckner (both COLO); El Paso Co., Pikes Peak, H.A. Imshaug 11953, 11992b (MSC); Garfield Co., 30 mi E Buford, S. Shushan 14242 (COLO); Chinese Wall, J. Marsh 5488; Flat Tops Wilderness, T.H. Nash 31500; Trappers Lake, J. Marsh 5534 (all ASU); Grand Co., Berthoud Pass, S. Shushan 25, 24772; W.A. Weber 53360; Grand Lake, R.A. Anderson 3260; Green Mountain, R.A. Anderson 3195; Never Summer Mountain, R.A. Anderson 3208; Tonahutu Creek Trail, R.A. Anderson 2369 (all COLO); Gunnison Co., Copper Creek, H.A. Imshaug 10476 (MSC); Gothic, S. Shushan 2825 (COLO); 1955, W.A. Weber (ABSL, US); 10 mi NE Gothic, 1955, W.A. Weber (MIN); Rustlers Gulch, H.A. Imshaug 10946 (MSC); Hinsdale Co., Rio Grande Reservoir, B.D. Ryan 12049 (ASU); Slumgullion Pass, R.A. Darrow 1252; Huerfano Co., near Wolf Lake, H.A. Imshaug 12223 (both MSC); La Veta, S. Shushan 5876 (CANL, COLO, FH, UC); Jackson Co., Big Creek Lakes, S. Shushan 5341 (COLO); 24 mi NW Cowdrey, 1955, S. Shushan (MIN); Park Range, 1955, S. Shushan (ABSL); Willow Creek Pass, 1947, R.A. Darrow (WIS); S. Shushan 8440 (US); near Cameron Pass, F.H. Erbisch 1204 (MIN); Lake Co., near Twin Lakes, H.A. Imshaug 11827 (MSC); Twin Lakes, 1873, J. Wolf (FH); Larimer Co., Battle Mountain, R.A. Anderson 2660; Bierdstadt Lake, R.A. Anderson 2487; Chapin Pass, R.A. Anderson 3493; Fall River Canyon, R.A. Anderson 1884 (all COLO); Longs Peak, W. Kiener 4325 (MICH); W. Kiener 6790 (MIN, WIS); W. Kiener 8148 (COLO); W. Keiner 9137 (MIN); W. Kiener 9180 (COLO, MICH); Mount Chiquita, R.A. Anderson 2915 (COLO); Rocky Mountain Nat. Park, W. Kiener 7135 (MIN); R.A. Anderson 1668 (COLO); C.M. Wetmore 15919 (MIN); Spruce Canyon, S. Shushan 5423 (BRY); Toll Memorial, R.A. Anderson 3611; Trail Ridge, W. Kiener 7135; R.A. Anderson 2214, 3545 (all COLO); Trail Ridge Pass, H.A. Imshaug 11240; Las Animas/Hue Cos., Cordova Pass, H.A. Imshaug 12116; Ouray Co., Blue Lake Pass, H.A. Imshaug 16948 (all MSC); Park Co., 11 mi E Jefferson, S. Shushan 5382 (COLO); Wheeler Lake, W.A. Weber 2781 (COLO, WIS); Pitkin Co., Elk Mountains, W.A. Weber 5836 (COLO); 6013 (WIS); 1955, W.A. Weber (ABSL, MIN); San Miguel Co., Old Ophir, R.A. Anderson 5990; Summit Co., Blue Lake Reservoir, R.A. Anderson 7078 (both COLM); Hoosier Pass, S. Shushan 2656a (COLO); N Star Mountain, 1977, R.A. Anderson (GZU). IDAHO. Idaho Co., Grave Peak, B. McCune 11459 (personal herb.); Salmon Mountain, B. McCune 12166 (SASK). MONTANA. Flathead Co., Mount Oberlin, R. Rosentreter 2741 (MONT); Gallatin Co., Grotto Falls, C.M. Wetmore 81545 (MIN); Glacier Co., Allen Creek, H.A. Imshaug 5988 (MSC); Piegan Pass, H.A. Imshaug 7997a; Reynolds Mountain, H.A. Imshaug 7756; Siyeh Pass, H.A. Imshaug 9017 (all MSC); Lake Co., Mission Mountains, B. McCune 9325 (SASK). NEW MEXICO. Sant Fe Co., 12 mi NE Santa Fe, I.M. Brodo 30456 (CANL); Taos Co., Gold Hill, H.A. Imshaug 12418; Wheeler Peak, H.A. Imshaug 12325 (both MSC); Williams Lake, T.H. Nash 22375 (ASU). OREGON. Lane Co., Fairview Mountain, W.A. Weber 35244 (COLO). UTAH. Duchesne Co., N Fork Duchesne River, C. Newberry 1426 (BRY); San Juan Co., Navaho Mountain, T.H. Nash 5159 (ASU, MSC); T.H. Nash 8182 (ASU); Summit Co., Allsop Lake Basin, C. Newberry 1431 (BRY). WASHINGTON. Steeple Peak, A.H. Smith 2325 (MICH); Clallam Co., Obstruction Peak, I.M. Brodo 14437 (CANL); Obstruction Point, H.A. Imshaug 17493, 17520b, 17541 (MSC); Okanogan Co., Roger Lake Trail, B.D. Ryan 30762b (ASU); Pierce Co., Burroughs Mountain, H.A. Imshaug 17391; Mount Fremont, H.A. Imshaug 17482b (both MSC). WYOMING. Albany Co., Centennial Valley, 1895, A. Nelson (FH, PH). Big Horn Co., Bald Mountain, T.H. Nash 21751 (ASU); Fremont Co., Brooks Lake, T.H. Nash 40231 (MIN); Johnson Co., Ten Sleep Lakes, 1897, T.A. Williams (MICH, NY, US, WIS); Park Co., 7 mi E Yellowstone Lake, C.M. Wetmore 81610 (MIN); Beartooth Plateau, B. McCune 19908 (personal herb.); Yellowstone Nat. Park, T.H. Nash 21577 (ASU); C.M. Wetmore 81730; Sheridan Co., Big Horn Mountains, C.M. Wetmore 12947, 12956, 12963, 12991, 12993; Teton Co., Craig Pass, C.M. Wetmore 82018, 82068, 82072 (all MIN).
Specimens of skyrin chemotype examined. CANADA. ALBERTA. Banff, Sanson 287 (FH); Consolation Valley, H.A. Imshaug 6763, 6798; Moraine Lake, H.A. Imshaug 6862 (both MSC); Queen Elizabeth Range, G.W. Scotter 7788 (CANL); opposite Angel Glacier, H.A. Imshaug 7075 (MSC). BRITISH COLUMBIA. Yoho Valley (FH). YUKON. Profile Mountain, G.W. Douglas 6399 (CANL). U.S.A. ALASKA. Kuskokwin River, L.A. Viereck 5076 (COLO); Mile 86 Haines Hwy., J.W. Thomson 22009 (WIS). ARIZONA. Santa Cruz Co., Santa Rita Mountains, C.G. Pringle (FH). COLORADO. Boulder Co., Calypso Cascades, R.A. Anderson 1867 (COLO, US); Chasm Lake, W. Kiener 4203 (COLO); Chaffee/Gunnison Cos., Lake Pass, H.A. Imshaug 11826; Clear Creek Co., Mt. Evans, H.A. Imshaug 11170; Costilla Co., Trinchera Peak, H.A. Imshaug 12205c (all MSC); Gilpin Co., James Peak, 1921, C.C. Plitt; Tolland, 1918, C.C. Plitt (both US); Gunnison Co., Elk Mountains, W.A. Weber 6013 (COLO); Elko Park, H.A. Imshaug 10744; Pieplant Mill, H.A. Imshaug 11303 (both MSC); Lake Co., Twin Lakes, 1873, J. Wolf (FH, NY); Larimer Co., Jewel Lake, R.A. Anderson 2547; Summit Co., Loveland Pass, D.D. Awasthi 33867 (both COLO). MONTANA. Flathead/Glacier Cos., Swiftcurrent Mountain, H.A. Imshaug 7826 (MSC). WASHINGTON. Clallam Co., Hurricane Ridge, I.M. Brodo 13218 (CANL); Okanagon Co., Logan Lake Trail, B.D. Ryan 30770 (ASU); Washakie Co., Ten Sleep Lakes, 1897, T.A. Williams (NY, US).
Specimens of atranorin strain examined. CANADA. ALBERTA. Consolation Valley, H.A. Imshaug 6798 (MSC); Moraine Lake, 1985, B.D. Ryan (ASU); Parker Ridge, R. Rosentreter 2141 (McCune personal herb.); Mount Edith Cavell, I.M. Brodo 31312. BRITISH COLUMBIA. Robb Lake, I.M. Brodo 21937; Trophy Mountain, I.M. Brodo 27237. YUKON. N Carpenter Lake, G.W. Scotter 19130; Onion Lake, G.W. Douglas 8779 (all CANL). U.S.A. ALASKA. Barrow, A. Fryday 8247 (MSC). COLORADO. Boulder Co., Longs Peak, W. Keiner 9180 (WIS); Wild Basin, R.A. Anderson 1865, 2185 (COLO); Clear Creek Co., McClellan Mountain, S. Shushan 8492 (BRY); Mount Evans, H.A. Imshaug 11155 (MSC); Mount Sniktau, R.S. Egan 12921 (MIN); El Paso Co., Glen Cove, Pikes Peak, H.A. Imshaug 12011 (MSC); Grand Co., Jackstraw Mountain, R.A. Anderson 2340; Mount Enentah, R.A. Anderson 3452 (both COLO); Gunnison Co., Elk Mountains, W.A. Weber 6015 (COLO, WIS); Pieplant Mill, H.A. Imshaug 11286; Rustlers Gulch, H.A. Imshaug 10946 (both MSC); Jackson Co., 31 mi S Walden, S. Shushan 8435 (COLO); Lake Co., near Twin Lakes, H.A. Imshaug 11827, 11845 (MSC); Twin Lakes, 1873, J. Wolf (PH); Larimer Co., Longs Peak, W. Keiner 9180 (MIN); Rio Blanco Co., Buford, S. Shushan 14208 (COLO). UTAH. Duchesne Co., Bedground Lake, C. Newberry 1426 (BRY); San Juan Co., Abajo Peak, T.H. Nash 8182 (ASU, CANL, COLO, WIS). WASHINGTON. Okanogan Co., Roger Lake Trail, B.D. Ryan 30762a (ASU).
Selected References. Magnusson (1947a), Fox & Purvis (1992), Thomson (1997), Giralt (2001), Mayrhofer & Moberg (2002 p. 105), 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: thin or thick, continuous, plane or more usually rugose, sometimes becoming subsquamulose surface: gray-brown or reddish brown, dull; margin: indeterminate; prothallus: lacking; vegetative propagules: absent Apothecia: adnate, frequent and often contiguous, up to 0.75-1.5 mm in diam. disc: dark brown, more commonly black, sometimes pruinose especially when young, quickly becoming convex thalline margin: 0.05-1 mm wide, entire, often becoming excluded; excipular ring: absent thalline exciple: 40-120 µm wide laterally; cortex: 10-20 µm wide; cells: up to 5.5-6.5 µm in diam. not pigmented, irregular and often not distinct; algal cells: up to 11-17 µm in diam. proper exciple: sometimes light brown, 15-30 µm wide laterally, expanding to 25-50 µm at periphery hymenium: 115-170 µm tall; paraphyses: 2-2.5 µm wide, not conglutinate, with apices up to 4-5 µm in diam., pigmented light brown and suffused in brown pigment to form a light brown epihymenium; hypothecium: hyaline or pale brown in specimens with dark thalli, 60-145 µm thick, inspersed with oil droplets asci: clavate, 80-100 x 16-29 µm, 8-spored ascospores: brown, 1-septate, ellipsoid, type A development, Physcia-type, (22-)27.5-29.5(-35) x (10.5-)13-14(-16.5) µm, usually retaining thick apical wall, cells often unequal in size from early development; torus: prominent walls: not ornamented Pycnidia: immersed in thallus conidia: bacilliform, 4-5 x c. 1 µm Spot tests: all negative Secondary metabolites: variolaric acid present or absent. Substrate and ecology: on moss in arctic-alpine habitats from sea level in the arctic to 4070 m in the southern part of its range in North America World distribution: frequent in arctic-alpine regions across the Northern Hemisphere Sonoran distribution: restricted to Coconino County, Arizona at elevations of 2470-4070 m, the southern limit of its range. Notes: Rinodina mniaraea is the only arctic-alpine representative of the genus in the study area and is well characterized by its muscicolous substrate, continuous thallus, convex apothecia and large, Physciatype spores. Two chemotypes, scattered elsewhere in its range, have been recognized by Mayrhofer and Moberg (2002) and should be sought. The var. cinnamomea Th. Fr. has a yellow to orange medulla (K+ purple, skyrin) and the var. mniaraieza (Nyl.) H. Magn. has a light gray thallus (K+ yellow, atranorin in the cortex). Rinodina turfacea (Wahlenb.) Körb., another arctic-alpine species that comes as far south as Colorado, is distinguished by its sessile apothecia, with persistently plane discs, expanded and columnar lower cortex, and the presence of sphaerophorin.