taxonID	type	description	language	source
F4ACFFE203BD51B48215E4147A100F9E.taxon	description	Fig. 2	en	Knudsen, Kerry, Cho-Ah-Ying, Jessica, Kocourková, Jana, Hodková, Eva, Malíček, Jiří, Wang, Yan (2025): The diversity of Acarosporaceae (Acarosporales, Lecanoromycetes) in California. MycoKeys 112: 183-210, DOI: 10.3897/mycokeys.112.138580
F4ACFFE203BD51B48215E4147A100F9E.taxon	diagnosis	Diagnosis. Similar in having a non-stratified thallus like the possibly extinct central European species Acarospora variegata but differing in not producing gyrophoric acid, not developing a distinct cortical layer which is poorly developed in A. variegata, and having an opaque white upper surface, not translucent in water.	en	Knudsen, Kerry, Cho-Ah-Ying, Jessica, Kocourková, Jana, Hodková, Eva, Malíček, Jiří, Wang, Yan (2025): The diversity of Acarosporaceae (Acarosporales, Lecanoromycetes) in California. MycoKeys 112: 183-210, DOI: 10.3897/mycokeys.112.138580
F4ACFFE203BD51B48215E4147A100F9E.taxon	etymology	Etymology. Named for the white non-translucent upper surface of the unstratified thallus.	en	Knudsen, Kerry, Cho-Ah-Ying, Jessica, Kocourková, Jana, Hodková, Eva, Malíček, Jiří, Wang, Yan (2025): The diversity of Acarosporaceae (Acarosporales, Lecanoromycetes) in California. MycoKeys 112: 183-210, DOI: 10.3897/mycokeys.112.138580
F4ACFFE203BD51B48215E4147A100F9E.taxon	description	Description. Thallus growing in the upper layer of substrate, endolithic to epilithic, covering 1 – 3 cm in width, an unstratified matrix of gelatinized intricate to anticlinal hyphae, 1 – 4 µm wide, intermixed with substrate crystal, with thin cracks splitting the upper layer into areoles irregular in shape, 0.3 – 1.0 mm wide, 200 – 400 µm thick. Upper surface ecorticate, white, epruinose, sometimes with small pale patches of reddish-brown pigment observed in thin sections at 1000 ×, not translucent when wet. Algae scattered or in thin clusters, algal cells 7 – 16 µm wide, not forming a continuous algal layer. Apothecia 0.1 – 0.5 mm wide, usually one per areole, oval to irregular in shape, disc black when dry, dull reddish brown when wet or not changing color, epruinose to lightly pruinose, rugulose or smooth, immersed and even with thallus surface or emergent and elevated above the thallus surface, with a thin white thalline margin 20 – 50 µm wide. Parathecium 10 – 40 µm wide, hyphae 2 µm wide, sometimes visible as parathecial ring around apothecial disc same color as epihymenium. Hymenium (100 –) 120 – 150 µm tall, cupular, usually tallest in center, epihymenium ca. 10 µm tall, reddish-brown, paraphyses mostly 1 µm wide, not branching, apices unexpanded, hymenial gel IKI + blue to red, hemiamyloid. Asci 80 – 90 × 22 – 26 µm, clavate, ascospores mostly 3 – 4 × 2 µm, ellipsoid, several hundred per ascus (n = 20). Subhymenium 20 – 25 µm tall, IKI + blue, euamyloid. Hypothecium Y-shaped, the central axis of hyphae extending down in a bundle, the arms 15 – 30 µm thick embracing the V-shaped subhymenium and continuous with parathecium. Pycnidia not observed. Chemistry: not producing secondary metabolites.	en	Knudsen, Kerry, Cho-Ah-Ying, Jessica, Kocourková, Jana, Hodková, Eva, Malíček, Jiří, Wang, Yan (2025): The diversity of Acarosporaceae (Acarosporales, Lecanoromycetes) in California. MycoKeys 112: 183-210, DOI: 10.3897/mycokeys.112.138580
0FC4DD0D2BF1539F8465FA5F25D9C0E3.taxon	description	Fig. 3	en	Knudsen, Kerry, Cho-Ah-Ying, Jessica, Kocourková, Jana, Hodková, Eva, Malíček, Jiří, Wang, Yan (2025): The diversity of Acarosporaceae (Acarosporales, Lecanoromycetes) in California. MycoKeys 112: 183-210, DOI: 10.3897/mycokeys.112.138580
0FC4DD0D2BF1539F8465FA5F25D9C0E3.taxon	diagnosis	Diagnosis. Similar to Acarospora veronensis but differing with a thicker cortex (50 –) 90 – 100 vs. 10 – 20 (– 30) µm and in being squamulose.	en	Knudsen, Kerry, Cho-Ah-Ying, Jessica, Kocourková, Jana, Hodková, Eva, Malíček, Jiří, Wang, Yan (2025): The diversity of Acarosporaceae (Acarosporales, Lecanoromycetes) in California. MycoKeys 112: 183-210, DOI: 10.3897/mycokeys.112.138580
0FC4DD0D2BF1539F8465FA5F25D9C0E3.taxon	etymology	Etymology. Named for its lack of an appealing and distinctive phenotype. Many brown Acarospora look similar, especially ones like A. indistincta in the morphological veronensis group having one immersed apothecium per brown areole or squamule.	en	Knudsen, Kerry, Cho-Ah-Ying, Jessica, Kocourková, Jana, Hodková, Eva, Malíček, Jiří, Wang, Yan (2025): The diversity of Acarosporaceae (Acarosporales, Lecanoromycetes) in California. MycoKeys 112: 183-210, DOI: 10.3897/mycokeys.112.138580
0FC4DD0D2BF1539F8465FA5F25D9C0E3.taxon	description	Description. Hypothallus endosubstratal, no algae observed. Thallus of convex dispersed squamules, 0.3 – 1 mm wide, 0.4 – 0.7 mm thick, with rounded edges, sometimes irregular in shape, usually not replicating by division, covering areas of several centimeters. Upper surface brown, shiny or dull, rarely pruinose. Lower surface white. Epicortex 10 – 40 µm thick. Cortex (60 –) 90 – 100 µm thick, of mostly round cells 2 – 5 µm wide, upper layer red brown, 10 µm thick, lower layer hyaline. Algal layer 90 – 150 µm thick, even, dense, continuous below apothecia, not interrupted by hyphal bundles, algal cells 10 – 15 µm wide. Medulla 180 – 250 µm thick, of anticlinal hyphae thin-walled and 2 µm thick, continuous with the stipe. The majority of squamules are sterile. Usually one apothecium per areole, immersed, below thallus level, punctiform, expanding up to 0.4 mm wide, disc dark brown, epruinose, sometimes becoming slightly elevated in thalline margin. Parathecium indistinct or 10 µm wide of narrow hyphae 1 µm wide. Hymenium mostly 90 – 100 µm tall, epihymenium 10 – 20 µm tall, red-brown, surface uneven, paraphyses 1.0 – 1.5 µm wide, hymenial gel IKI + blue turning red, hemiamyloid. Asci clavate 50 – 60 × 15 – 21 µm, ascospores several hundred, thin ellipsoid, 3 – 4 × 1 – 1.5 µm (n = 20). Subhymenium 40 – 50 µm tall, IKI + blue, euamyloid. Hypothecium 20 – 30 µm tall, IKI-. Pycnidia not observed. Chemistry: not producing secondary metabolites.	en	Knudsen, Kerry, Cho-Ah-Ying, Jessica, Kocourková, Jana, Hodková, Eva, Malíček, Jiří, Wang, Yan (2025): The diversity of Acarosporaceae (Acarosporales, Lecanoromycetes) in California. MycoKeys 112: 183-210, DOI: 10.3897/mycokeys.112.138580
8C2D862B05065C3EA1F08FF725AA6418.taxon	description	Fig. 4	en	Knudsen, Kerry, Cho-Ah-Ying, Jessica, Kocourková, Jana, Hodková, Eva, Malíček, Jiří, Wang, Yan (2025): The diversity of Acarosporaceae (Acarosporales, Lecanoromycetes) in California. MycoKeys 112: 183-210, DOI: 10.3897/mycokeys.112.138580
8C2D862B05065C3EA1F08FF725AA6418.taxon	diagnosis	Diagnosis. Similar to Acarospora applanata but differing in being squamulose.	en	Knudsen, Kerry, Cho-Ah-Ying, Jessica, Kocourková, Jana, Hodková, Eva, Malíček, Jiří, Wang, Yan (2025): The diversity of Acarosporaceae (Acarosporales, Lecanoromycetes) in California. MycoKeys 112: 183-210, DOI: 10.3897/mycokeys.112.138580
8C2D862B05065C3EA1F08FF725AA6418.taxon	etymology	Etymology. Named after Stephen Sharnoff, lichen photographer, who produced the classic book A Field Guide to California Lichens (Sharnoff 2014). He collected the first specimen on Eureka Peak in Joshua Tree National Park. A picture of the holotype of Acarospora sharnoffii as A. obnubila is in his book.	en	Knudsen, Kerry, Cho-Ah-Ying, Jessica, Kocourková, Jana, Hodková, Eva, Malíček, Jiří, Wang, Yan (2025): The diversity of Acarosporaceae (Acarosporales, Lecanoromycetes) in California. MycoKeys 112: 183-210, DOI: 10.3897/mycokeys.112.138580
8C2D862B05065C3EA1F08FF725AA6418.taxon	description	Description. Hypothallus endosubstratal, no algae observed. Thallus of squamules dispersed to contiguous, 0.5 – 2.0 mm wide, with stipe raised distinctly above substrate, 0.3 – 0.45 mm thick, with an uneven and irregular topography, replicating by division. Upper surface shiny brown, epruinose or pruinose, with abundant abscission fissures. Lower surface ecorticate, white or brown. Epicortex continuous, 10 – 40 µm thick. Cortex 20 – 60 µm thick, upper layer brown 8 – 12 µm thick, lower layer hyaline, of disarticulated anticlinal hyphae, cells round to irregular, 2 – 5 µm wide. Algal layer 70 – 100 µm thick, upper surface even to uneven, continuous below apothecia, algal cells mostly 10 – 12 µm wide. Medulla 100 – 200 µm thick, hyphae thin-walled, mostly 4 µm wide, continuous with stipe, becoming periclinal along lower surface. Apothecia rare, usually one per squamule in center, deeply immersed, disc blackish when dry, brownish when wet, 0.3 – 0.5 mm wide, epruinose, rough, rarely disc expanded to 1 mm wide, reducing the squamule to thalline margin. Parathecium of narrow hyphae 1 µm wide, expanding to ca. 20 µm wide around disc, merging into the cortex. Epihymenium 8 – 12 µm tall, surface uneven, brown. Hymenium 70 – 90 (– 110) µm tall, epihymenium 10 µm tall blackish brown, paraphyses 1.0 – 1.5 µm wide, apices barely expanded in gel caps, hymenial gel IKI + blue to red, hemiamyloid. Asci cylindrical, 50 – 80 × 10 – 15 µm wide, ascospores usually small, 2.0 – 4.0 × 1.0 – 1.5 µm, often with two oil drops (n = 20). Subhymenium 25 – 45 µm tall, IKI + blue, euamyloid. Hypothecium 10 µm thick. Pycnidia not observed. Chemistry: not producing secondary metabolites.	en	Knudsen, Kerry, Cho-Ah-Ying, Jessica, Kocourková, Jana, Hodková, Eva, Malíček, Jiří, Wang, Yan (2025): The diversity of Acarosporaceae (Acarosporales, Lecanoromycetes) in California. MycoKeys 112: 183-210, DOI: 10.3897/mycokeys.112.138580
CCD32E78A3B658F7A0B5E1EE12CA072B.taxon	description	Fig. 5	en	Knudsen, Kerry, Cho-Ah-Ying, Jessica, Kocourková, Jana, Hodková, Eva, Malíček, Jiří, Wang, Yan (2025): The diversity of Acarosporaceae (Acarosporales, Lecanoromycetes) in California. MycoKeys 112: 183-210, DOI: 10.3897/mycokeys.112.138580
CCD32E78A3B658F7A0B5E1EE12CA072B.taxon	diagnosis	Diagnosis. Similar to A. veronensis but with a thicker cortex, 30 – 50 (– 70) vs. 15 – 30 µm and a usually higher hymenium (100 –) 120 (– 150) vs. 80 – 90 (– 100) µm.	en	Knudsen, Kerry, Cho-Ah-Ying, Jessica, Kocourková, Jana, Hodková, Eva, Malíček, Jiří, Wang, Yan (2025): The diversity of Acarosporaceae (Acarosporales, Lecanoromycetes) in California. MycoKeys 112: 183-210, DOI: 10.3897/mycokeys.112.138580
CCD32E78A3B658F7A0B5E1EE12CA072B.taxon	etymology	Etymology. Named after the type locality in Tejon Ranch in Tehachapi Mountains.	en	Knudsen, Kerry, Cho-Ah-Ying, Jessica, Kocourková, Jana, Hodková, Eva, Malíček, Jiří, Wang, Yan (2025): The diversity of Acarosporaceae (Acarosporales, Lecanoromycetes) in California. MycoKeys 112: 183-210, DOI: 10.3897/mycokeys.112.138580
CCD32E78A3B658F7A0B5E1EE12CA072B.taxon	description	Description. Hypothallus endosubstratal, no algae observed. Thallus areolate, areoles 0.2 – 1.1 mm wide, 150 – 270 µm thick, angular, contiguous to dispersed, marginal areoles can be prolongated and lobate, becoming elevated by a mycelial base, replicating by division, covering areas up to 4 cm or more. Upper surface light to dark brown, sometimes partly black, epruinose, rugulose to smooth. Lower surface white. Epicortex lacking. Cortex 30 – 50 (– 70) µm thick, upper layer dark brown, 10 – 30 µm thick, lower layer hyaline, hyphae usually disarticulated, cells round to irregular, mostly small, 1 – 3 µm wide, rarely up to 5 µm wide. Algal layer up to 100 µm thick, uninterrupted, algal cells 8 – 12 µm wide, continuous below apothecia. Medulla white, 0.2 – 0.7 mm thick, hyphae obscure in water, intricate and gelatinized, mostly 1 µm wide. Apothecia immersed, usually one per areole, sometimes 2 – 5, sometimes with areole reduced to a prominent margin, the disc dark, epruinose, same color as thallus, 0.1 – 0.3 mm wide, rarely to 0.5 mm wide. Parathecium indistinct to 20 µm wide of narrow hyphae 1 µm wide, merging with the cortex. Hymenium cupular, (100 –) 120 (– 150) µm tall, epihymenium dark reddish brown, 10 µm tall, paraphyses 1 – 2 µm wide, apices unexpanded or slightly widened in terminal reddish brown gel cap, hymenial gel IKI + reddish orange, hemiamyloid. Asci 90 – 120 × 10 – 20 µm, cylindrical to clavate, ascospore several hundred per asci, small, thin ellipsoid, 3 – 4 × 1 µm (n = 20). Subhymenium 20 – 40 µm tall, IKI + blue. Hypothecium indistinct to 10 µm thick. Pycnidia not observed. Chemistry: not producing secondary metabolites.	en	Knudsen, Kerry, Cho-Ah-Ying, Jessica, Kocourková, Jana, Hodková, Eva, Malíček, Jiří, Wang, Yan (2025): The diversity of Acarosporaceae (Acarosporales, Lecanoromycetes) in California. MycoKeys 112: 183-210, DOI: 10.3897/mycokeys.112.138580
1A167F0EBCBE566BB3DB2E975B31CF99.taxon	description	Fig. 6	en	Knudsen, Kerry, Cho-Ah-Ying, Jessica, Kocourková, Jana, Hodková, Eva, Malíček, Jiří, Wang, Yan (2025): The diversity of Acarosporaceae (Acarosporales, Lecanoromycetes) in California. MycoKeys 112: 183-210, DOI: 10.3897/mycokeys.112.138580
1A167F0EBCBE566BB3DB2E975B31CF99.taxon	diagnosis	Diagnosis. Similar to Sarcogyne nogalensis but becoming squamulose.	en	Knudsen, Kerry, Cho-Ah-Ying, Jessica, Kocourková, Jana, Hodková, Eva, Malíček, Jiří, Wang, Yan (2025): The diversity of Acarosporaceae (Acarosporales, Lecanoromycetes) in California. MycoKeys 112: 183-210, DOI: 10.3897/mycokeys.112.138580
1A167F0EBCBE566BB3DB2E975B31CF99.taxon	etymology	Etymology. Based on the species forming distinctive fascicles of squamules with interconnected stipes while in the process of splitting apart when replicating by division.	en	Knudsen, Kerry, Cho-Ah-Ying, Jessica, Kocourková, Jana, Hodková, Eva, Malíček, Jiří, Wang, Yan (2025): The diversity of Acarosporaceae (Acarosporales, Lecanoromycetes) in California. MycoKeys 112: 183-210, DOI: 10.3897/mycokeys.112.138580
1A167F0EBCBE566BB3DB2E975B31CF99.taxon	description	Description. Hypothallus endosubstratal, no algae observed. Thallus of squamules or subsquamulose areoles, 0.2 – 0.5 (– 1.0 – 2.0) mm wide, 250 – 500 μm thick, with stipe 50 – 200 μm high, forming dispersed to contiguous colonies up to 3 × 2 cm, sometimes imbricate, with an uneven`topography, replicating by division. Upper surface light or dark brown, rarely shiny, epruinose, the lobes curling downward around the stipe, smooth or with abscission fissures when beginning to replicate by division, forming fasciculate structures of interconnected stipes of squamules during replication. Lower surface pale white sometimes with an undertone of pale brown, corticate with periclinal hyphae, hyaline, up to 20 μm thick. Epicortex, uneven, ca 10 μm thick. Cortex 20 – 40 (– 60) μm thick, upper layer ca. 10 μm thick of dark brown round cells, lower layer hyaline of round cells or ellipsoid cells 2 – 3 × 1.5 – 2.0 μm. Algal layer 70 – 120 μm thick, dense, uninterrupted, continuous below apothecia. Medulla obscure, white to pinkish-brown, 100 – 200 μm thick, hyphae continuous with stipe, 2 – 4 μm wide, thin-walled, sometimes disarticulated cells expanded or irregular, 4 – 8 μm wide. Apothecia immersed, darker brown than thallus, in San Bernardino Mountains specimens black, often concave, 0.1 – 0.6 mm wide, epruinose, occasionally looking pseudolecanorine with squamule reduced to thalline margin, sometimes apothecia in raised parathecial margin. Parathecium up to 60 μm wide, hyphae 2 – 3 μm wide with apices in brown pigment caps to 5 μm wide, merging with cortex. Hymenium 60 – 80 (– 120) μm tall, highest in center, epihymenium 10 – 15 μm tall, light brown, paraphyses 1.5 – 2.5 μm wide, apices unexpanded in brown gel caps 2 – 4 μm wide with upper black pigment line, hymenial gel IKI + dark blue bleeding into parathecium and hypothecium. Asci (40 –) 50 – 75 × 10 – 20 μm, narrowly cylindrical to inflated clavate, ascospores, 2 – 4 × 1.5 – 2.5 µm (n = 20). Subhymenium 20 – 40 µm tall, IKI + blue. Hypothecium 10 – 30 µm tall, hyphae 2 µm wide. No pycnidia observed. Chemistry: not producing secondary metabolites.	en	Knudsen, Kerry, Cho-Ah-Ying, Jessica, Kocourková, Jana, Hodková, Eva, Malíček, Jiří, Wang, Yan (2025): The diversity of Acarosporaceae (Acarosporales, Lecanoromycetes) in California. MycoKeys 112: 183-210, DOI: 10.3897/mycokeys.112.138580
