1	Thallus saxicolous or lignicolous	2
–	Thallus corticolous	31
2	Thallus lobate or sublobate	3
–	Thallus not lobed	5
3	Disc dark, ruby-colored	L. rubina
–	Disc light-colored, pale pink, greenish brown to yellow–brown	4
4	Thallus usually areolate or sometimes sublobate, paraphyses tips swollen up to 3 μm wide, conidia 20–25 × 1 μm, thallus Pd+ orange	L. albescens (Myriolecis albescens)
–	Thallus lobate, resetting, paraphyses tips hardly swollen, conidia absent, thallus Pd–	L. valesiaca
5	Thallus inconspicuous, immersed or with dispersed areoles, ascospores 10–14 × 5–6.5 μm, thallus UV–	L. polytropa
–	Thallus clearly visible	6
6	On calcareous rocks or wood/logs	7
–	On non-calcareous rocks	9
7	Common on wood/logs, thalline margin excluded finally	L. anopta
–	Only on calcareous rocks, thalline margin persistent	8
8	Thallus starkly white or pale gray, apothecia 0.1–0.7 mm diam., thallus Pd+ orange	L. albescens (Myriolecis albescens)
–	Thallus gray to blackened, apothecia 0.5–1.4 mm diam., thallus Pd–	L. semipallida (Myriolecis semipallida)
9	Disc pruinose	10
–	Disc not pruinose	13
10	Prothallus green–black, thalline margin ±excluded, disc densely gray pruinose, epihymenium green– or blue–gray, containing zeorin, ±gangaleoidin, and usnic acid	L. sulphurea
–	Prothallus whitish, thalline margin persistent, containing small or large crystals, disc slightly or faintly pruinose, epihymenium brownish, containing ±chloratranorin	11
11	Thalline margin with small, irregular crystals (<10 μm diam.) not dissolving in K, thallus white to yellow–white, K+ indistinct yellow	L. horiza
–	Thalline margin with large crystals (>10 μm diam.), thallus grayish, yellowish or brownish, K+ yellow or yellow turning to red	12
12	Thallus not glossy, apothecia 1–2 mm diam., disc yellow–brown, red–brown to black, ascospores 9–15 × 6–8.5 μm, containing ±roccellic acid and norstictic acid	L. cenisia
–	Thallus somewhat glossy, apothecia 0.4–0.7 mm diam., disc waxy or pale to greenish orange, ascospores 8–11.5 × 4–6.5 μm	L. plumosa
13	Disc blackish, epihymenium bluish or greenish, not reddish, orangish or brownish	14
–	Disc yellowish to brownish, epihymenium yellowish to brownish	16
14	Thallus grayish white to white, prothallus blackish when present, ascospores smaller, 7–13 × 4–6.5 μm, thallus Pd+ yellow, medulla Pd+ pale yellow	L. oreinoides
–	Thallus green–yellow to yellowish, prothallus absent, ascospores larger, 11–15 × 6–9 μm, thallus Pd–	15
15	Thallus not shining, apothecia 0.7–4 mm diam., disc not shining, hymenium 80–110 μm high, ascospores 11–15 × 6–9 μm	L. decorata
–	Thallus somewhat shining and waxy, apothecia ca 0.5 mm diam., disc shining, hymenium 55–65 μm high, ascospores 11–13 × 6–7 μm	L. marginata
16	Disc pale to green–brown or black–green	17
–	Disc pale brown, red–brown to dark brown	19
17	Thallus somewhat glossy, prothallus whitish to whitish gray when present, apothecia 0.4–0.7 mm diam., disc waxy, pale to greenish orange, ascospores 8–11.5 × 4–6.5 μm, thallus Pd+ pale orange, containing atranorin and chloratranorin	L. plumosa
–	Thallus not glossy, prothallus black when present, apothecia 0.3–1 mm diam., disc not waxy, pale yellow to greenish brown or greenish black, ascospores 10–14 × 5–7 μm, thallus Pd–, containing usnic acid and zeorin	18
18	Thallus continuous and well-developed, disc green–brown to green–black, epihymenium green–brown to brown, hymenium 60–70 μm high, pycnoconidia 23–25 × 0.5–1 μm, thallus UV+ dull orange	L. intricata
–	Thallus inconspicuous with dispersed areoles, disc pale yellow to pale brown, epihymenium hyaline to yellow– or red–brown, hymenium 45–60 μm high, pycnoconidia 18–22 ×1 μm, thallus UV–, containing rangiformic acid and ±eulecanoral	L. polytropa
19	Thallus richly sorediate, disc dark brown and shiny	L. ussuriensis
–	Thallus not sorediate, disc not shiny	20
20	Thallus pale to medium yellow or yellow–green, not white or gray	L. frustulosa
–	Thallus pale to white, gray or dark gray	21
21	Apothecia smaller, up to ca 0.5 mm diam.	22
–	Apothecia larger, 0.5–2.5 mm diam.	23
22	Thallus medium to dark gray, epihymenium yellow to brown, ascospores 9–15 × 4–6 μm, often guttulate and appearing 1-septate, reaction all negative else epihymenium K+ yellow	L. helicopis
–	Thallus grayish white, epihymenium brownish red, ascospores 12–13 × 5–6 μm, thallus K+ pale yellow, epihymenium K–	L. subimmersa
23	Prothallus whitish	24
–	Prothallus absent	28
24	Thallus pale, gray to dark gray, thalline margin with irregular or large crystals	25
–	Thallus white, grayish white or yellowish white, thalline margin with small crystals	27
25	Ascospores narrower, 10–15 × 5–7 μm, thallus Pd–	L. subimmergens
–	Ascospores wider, 9–15 × 6–8.5 μm, thallus Pd+ weakly yellow or yellow turning to red	26
26	Epihymenium pale orange to red–brown without granules, paraphyses tips red–brown, asci 50–60 × 12–21 μm, containing zeorin	L. campestris
–	Epihymenium brown to olivaceous brown with coarse granules dissolving in K, paraphyses tips olivaceous, asci 45–50 × 7–9 μm, containing ±roccellic acid and ±norstictic acid	L. cenisia
27	Disc orange, red–orange to red–brown, thalline margin with small irregular crystals not dissolving in K, hypothecium without oil droplets, thallus Pd–, containing ±chloratranorin	L. horiza
–	Disc brown to dark brown, thalline margin with small and large crystals dissolving in K, hypothecium inspersed with oil droplets, thallus Pd+ light orange, containing zeorin	L. melacarpella
28	Ascospores smaller, 8–12 × 4.5–5 μm	L. orientalis
–	Ascospores larger, 9–15 × 5–8.5 μm	29
29	Thalline margin with only large crystals not dissolving in K, thallus yellowish gray to whitish gray, ascospores narrower, 9–15 × 5–7 μm, prothallus absent	L. pseudistera
–	Thalline margin with small crystals, thallus whitish to grayish white, ascospores wider, 10.5–15 × 6.5–8.5 μm, prothallus white when present	30
30	Disc orange, red–orange or red–brown, thalline margin with small irregular crystals not dissolving in K, ascospores 12–15 × 6.5–8.5 μm, thallus K+ indistinct yellow, Pd–, containing ±chloratranorin	L. horiza
–	Disc brown to dark brown, thalline margin with small and large crystals dissolving in K, ascospores 10.5–13.5 × 7.5–8.5 μm, thallus K+ yellow, Pd+ light orange, containing zeorin	L. melacarpella
31	Thallus sorediate	32
–	Thallus not sorediate	39
32	Apothecia absent or rarely seen	33
–	Apothecia present	35
33	Thallus UV–, apothecia not seen, containing stictic acid	L. layana
–	Thallus UV+ pale orange or ice blue, apothecia rarely seen	34
34	Thallus pale gray, prothallus pale gray, apothecia not pruinose, ascospores 7–10 × 3–4 μm, thallus Pd± yellow, UV+ pale orange, containing chloratranorin	L. barkmaniana
–	Thallus yellow to greenish, occasionally with blue or gray tints, prothallus white and fibrous, often with one or two blue–gray zones, apothecia faintly or heavily white pruinose, ascospores 11–14 × 6–9 μm, thallus Pd–, UV+ ice blue (or violet), containing usnic acid and porphyrilic acid	L. thysanophora
35	Apothecia pruinose	36
–	Apothecia not pruinose	38
36	Ascospores smaller, 11–14 × 6–9 μm	L. thysanophora
–	Ascospores larger, 15–24 × 7–12 μm	37
37	Thallus white or yellowish white, asci 8- or 6-spored, ascospores 15–22 × 7–12 μm	L. pachycheila
–	Thallus yellowish–blue green, asci 8-spored, ascospores 15–20 × 9–12 μm	L. sibirica
38	Thallus pale gray, apothecia 0.4–0.7 mm diam., ascospores 7–10 × 3–4 μm	L. barkmaniana
–	Thallus yellowish gray to greenish gray, apothecia 0.2–0.6 mm diam., ascospores 12–15.5 × 6–8.5 μm, containing chodatin, demethlchodatin, and thiophanic acid	L. leproplaca
39	Prothallus distinct, whitish, grayish or blackish	40
–	Prothallus indistinct or absent	47
40	Prothallus whitish or grayish, but not blackish	41
–	Prothallus blackish	44
41	Thalline margin with large crystals (> 10 μm diam.) not dissolving in K	42
–	Thalline margin with small crystals (< 10 μm diam.)	43
42	Apothecia pale orange to yellowish brown, sometimes slightly pruinose on disc, epihymenium hyaline to yellow–brown with numerous small crystals (chlarotera-type), ascospores 9–13 × 5–7 μm, containing gangaleoidin, chloratranorin, chlorolecideoidin, leoidin, and norgangaleoidin	L. leprosa
–	Apothecia dark reddish brown to brownish black, not pruinose, epihymenium reddish brown with fine brown granules (pulicaris-type), ascospores 11–14 × 6–8 μm, containing fumarprotocetraric acid, ±roccellic acid	L. pulicaris
43	Subhymenium 60–80 μm high, asci consistently 8-spored, ascospores 15–20 × 8–11 μm, pycnidia brown–black with pycnoconidia 20–25 × 0.5 μm, containing zeorin	L. chionocarpa
–	Subhymenium 180–220 μm high, asci 8-spored or 16-spored, ascospores 12–16 × 6–8 μm, pycnidia absent	L. japonica
44	Thalline margin with granular crystals dissolving in K	L. megalocheila
–	Thalline margin with large crystals not dissolving in K	45
45	Disc paler, orange–brown or pale red–brown, flat to slightly convex, epihymenium inspersed with coarse granules, thallus Pd–, containing pannarin, ±placodialic acid, and ±roccellic acid	L. cinereofusca
–	Disc darker, dark reddish brown to brownish black, flat to slightly concave, epihymenium without granules, thallus Pd+ faintly yellow	46
46	Paraphyses tips reddish brown (or faintly yellow), asci wider, 45–55 × 18–22 μm, ascospores larger, 11.5–14.5 × 6–8.5 μm, containing gangaleoidin and usually traces of californin	L. argentata
–	Paraphyses tips dark brown, asci narrower, 50–60 × 8–12 μm, ascospores smaller, 9–14 × 5–8 μm, containing zeorin	L. iseana
47	Thalline margin finally excluded	48
–	Thalline margin permanent	51
48	Disc pruinose, thallus not corticate, containing decarboxysquamatic acid	L. strobilina
–	Disc not pruinose, thallus corticate, decarboxysquamatic acid absent	49
49	Asci 16- or 32-spored, thallus C–, K–, KC–, containing no substance	L. sambuci
–	Asci 8-spored, thallus C± orange, KC± yellow to orange, containing usnic acid, zeorin and xanthones	50
50	Thallus yellow–green to gray–green, disc pale yellow to greenish, when young the exciple crenulate and containing algae	L. confusa
–	Thallus yellowish–white to greenish black, disc pinkish brown to greenish black, when young the exciple smooth and lacking algae	L. symmicta
51	Disc and epihymenium darker, brown, red–brown to dark brown, not pruinose	52
–	Disc or epihymenium paler, pinkish, pale orangish, green–brown, yellow–brown, orange–brown to pale red–brown, pruinose or not	57
52	Thalline margin with small crystals (allophana-type) not dissolving in K	53
–	Thalline margin with large crystals (pulicaris-type)	54
53	Thallus darker, bluish, olivish or pale brownish gray, disc brownish, amphithecial cortex present, epihymenium with granules on the surface not dissolving in K, hypothecium shorter, 15–25 μm high, oil droplets present in apothecial section	L. baekdudaeganensis
–	Thallus paler, greenish or yellowish gray, disc reddish brown, amphithecial cortex indistinct or absent, epihymenium without granules, hypothecium taller, 50–75 μm high, oil droplets absent	L. imshaugii
54	Epihymenium without granules, ascospores 10.5–16.5 × 6–9.5 μm	55
–	Epihymenium with coarse, hyaline to brown granules (chlarotera-type), ascospores 8–12 × 4.5–7 μm	56
55	Apothecia smaller, 0.4–0.8 mm diam., ascospores 11.5–14.5 × 6–8.5 μm, thallus Pd+ weakly yellow, containing gangaleoidin	L. argentata
–	Apothecia larger, up to 1.6 mm diam., ascospores 10.5–16.5 × 6–9.5 μm, thallus Pd–, containing zeorin	L. perplexa
56	Apothecia not constricted at base, disc slightly convex when mature, hymenium including subhymenium 80–100 μm high, hypothecium 120–150 μm high, asci 40–50 × 7–12 μm, ascospores 8–10 × 4.5–6 μm, pycnidia absent, thallus Pd+ orange	L. nipponica
–	Apothecia slightly constricted at base, disc extremely convex when mature, hymenium including subhymenium 150–200 μm high, hypothecium 70–110 μm high, asci 50–60 × 10–15 μm, ascospores 9–12 × 6–7 μm, pycnidia present, thallus Pd–	L. sulcata
57	Asci 12- or 16-spored	L. loekoesii
–	Asci 8-spored	58
58	Ascospores smaller, 7–10 × 4–5 μm, thallus C–, K–, KC– (or KC+ yellow), Pd–	L. saligna
–	Ascospores larger, 9–15 × 5–9.5 μm, thallus K+ yellow, Pd+ yellow–orange to orange	59
59	Ascospores 9–11.5 × 5–7 μm, thallus K+ weakly yellow, Pd+ sulphur yellow, thallus areoles somewhat shiny, containing psoromic acid and usnic acid	L. varia
–	Ascospores 9–15 × 5–9.5 μm, thallus K+ distinct yellow or yellow turning to red, Pd+ pale yellow to yellow orange, thallus not shiny	60
60	Thalline margin with numerous small crystals (allophana-type), containing ±stictic acid	61
–	Thalline margin with large crystals not dissolving in K (pulicaris-type)	62
61	Disc carneous to pinkish, flat to convex, heavily pruinose, epihymenium gray–brown, thallus K+ yellow or yellow turning to red, Pd+ orange, containing chloratranorin, ±norstictic acid, ±protocetraric acid, ±virensic acid, ±connorstictic acid, ±conprotocetraric acid, and ±salazinic acid	L. caesiorubella
–	Disc yellowish brown to dark reddish brown, flat to slightly concave, slightly pruinose, epihymenium dark brown to blackish brown, thallus K+ yellow, Pd+ pale yellow, containing hafellic acid, zeorin, and usnic acid	L. hafelliana
62	Thallus pale to medium gray, apothecia larger, 0.7–1.5 mm diam., disc not pruinose, epihymenium red–brown, paraphyses anastomosed, ascospores larger, 10–14.5 × 7–8.5 μm, containing pannarin and ±placodialic acid	L. cinereofusca
–	Thallus yellow–white to yellow gray, apothecia smaller, 0.2–1 mm diam., disc slightly pruinose, epihymenium pale to red–brown, paraphyses sparsely branched, ascospores smaller, 9–13.5 × 5–7 μm	63
63	Apothecia 0.5–1 mm diam., prothallus absent, thallus Pd–, containing ±roccellic acid and ±fatty acid	L. hybocarpa
–	Apothecia 0.2–0.7 mm diam., prothallus gray when present, thallus Pd+ pale orange, containing gangaleoidin, chloratranorin, chlorolecideoidin, leoidin, and norgangaleoidin	L. leprosa