Key to the lichen genera of Singapore and surroundings

by H. Sipman, 18 June 2007 !!!UNDER CONSTRUCTION!!!

The key is based on recent observations in Singapore and surroundings. Additional genera are expected, because the region is poorly known lichenologically.  For explanation of the terms, see glossary. Please inform me, when you find additional genera, so that I can add them to the key.

1a Thallus with fruticose part (divided in rounded or flattened slips or branches standing or hanging free in the air, without clearly differentiated underside, attached to the substrate only in a small, basal area) --- 2
1b Thallus not fruticose (flattened and attached to the substrate by its whole underside or by parts of it or by thread-like structures (rhizines or cilia)) --- 3

2a Thallus additionally with flattened squamules, which are green-grey above and white below; vertical parts hollow; cephalodia absent --- Cladonia
2b Thallus uniform; usually on tree bark (expected) --- Ramalina

3a Thallus foliose (with free underside), often with a lower cortex, attached to the substrate by thread-like structures (rhizines or cilia) or by small spots on the underside, usually several cm. wide --- 4
3b Thallus crustose (attached to the substrate by the whole underside), or squamulose (with scale-like compartments which are more or less raised and rarely exceed 1-2 mm) --- 99

4a Thallus spongy, composed of loosely connected filaments --- 5
4b Thallus compact, sometimes with filamentous cover on lower and/or upper side --- 6

5a Photobiont a cyanobacterium (expected) --- Dictyonema
5b Photobiont Trentepohlia (expected) --- Coenogonium

6a Photobiont a cyanobacterium, usually Nostoc --- 7
6b Photobiont a green alga, usually Trebouxia --- 48

7a Thallus gelatinous, in section composed of a gelatinous sheet containing Nostoc cells in chains and fungal hyphae --- 8
7b Thallus not gelatinous, in section composed of an upper cortex, and algal layer with dense algal cells, and an algae-free medullary layer composed of fungal hyphae surrounded by air --- 10

8a Thallus in section with an outer, one cell wide, cellular layer --- Leptogium
8b Thallus in section without outer cellular layer --- 9

9a Ascospores without septa --- Physma byrsaeum (Ach.) Tuck.
9b Ascospores transversely septate to muriform --- Collema

10a Thallus with white dots below (cyphellae; expected) --- Sticta
10b Thallus without such dots; upper side often concentrically striate --- Coccocarpia

48a (6) Thallus bright yellow, in shade more greenish yellow (expected) --- Candelaria concolor (Dicks.) Stein
48b Thallus pale- to greenish grey --- 50

50a Rhizines and/or cilia (marginal rhizines) present, distinct from the beginning; lower cortex present or absent --- 51
50b Rhizines and cilia absent or very short; lower cortex always present, black --- 73

51a Cilia present --- 52
51b Cilia absent --- 67

52a Lower side without cortex --- Heterodermia
52b Lower side with cortex --- 54

54a Lower side with rhizines absent from marginal zone --- Parmotrema
54b Lower side with rhizines till the margin --- 55

55a Cilia with swollen base (bulbate) --- 56
55b Cilia without swollen base --- 57

56a Thallus upper side greenish to yellowish grey, K-, KC+ yellow (usnic acid present; expected) --- Relicina (key to species)
56b Thallus upper side pale grey, K+ yellow, KC- (atranorin present; expected) --- Bulbothrix

57a Thallus upper side greenish to yellowish grey, K-, KC+ yellow (usnic acid present; expected) --- Relicinopsis
57b Thallus upper side pale grey, K+ yellow, KC- (atranorin present) --- 58

58a Medulla white, C+ red or rose; lobe axils rounded (expected) --- Parmelinopsis
58b Medulla yellow, C- or C+ yellow; lobe axils not rounded (expected) --- Myelochroa

67a (51) Thallus shallowly dissected, with rounded, ca. 3-10 mm wide lobes; rhizines on underside absent from marginal zone --- Parmotrema
67b Thallus deeply dissected, with linear to irregular lobes; rhizines on underside present till the margin --- 68

68a Lower side brown at the margin, black towards the centre; ascospores without septa, colourless (expected) -- --- Canoparmelia
68b Lower side white or yellowish or grey to black at the margin, of the same colour or darker towards the centre; ascospores transversely septate and grey to brown --- 71

71a Pseudocyphellae present along the margin and sometimes on the surface, elongate and sometimes forming a reticulate pattern; cortex often without atranorin (K-); ascocarps with lecideine margin --- Pyxine
71b Pseudocyphellae absent; cortex always containing atranorin (K+ yellow); ascocarps with lecanorine margin --- 72

72a Upper surface finely longitudinally striate, principally composed of hyphae running in the direction of the lobe, showing as circles in transverse section --- Heterodermia
72b Upper surface without longitudinal striation, composed of unoriented hyphae, mostly showing as lines in transverse section --- Physcia

73a (50) Thallus upper surface K+ yellow (with atranorin), with marginal pseudocyphellae, continuous in the centre --- Dirinaria
73b Thallus upper surface K- (without atranorin), without marginal pseudocyphellae, with discrete lobes in the centre (expected)  --- Hyperphyscia (key to species)

99a (3) Ascocarps present --- 100
99b Ascocarps absent (only a few characteristic taxa treated) --- 290

100a Ascocarps disc-like, more or less rounded; hymenium exposed --- 101
100b Ascocarps elongate or star-like branched; hymenium exposed or not --- 200
100c Ascocarps flask-shaped, rounded or in groups; hymenium not exposed, but ascocarp opening by a dot-like pore --- 250

101a Ascocarps distinctly stalked; stalk longer than apothecium height --- 102
101b Ascocarps sessile or immersed --- 104

102a Thallus squamulose; ascocarps pale brown --- Thysanothecium scutellatum (Fr.) D.J. Gallow.
102b Thallus crustose --- 103

103a Ascocarps black on long, black, needle-like stalk, altogether ca. 1 mm long; on trunks --- Calicium hyperelloides Nyl.
103b Ascocarps pink on pale, ca. 1 mm wide and several mm long stalks; on road banks (expected)  --- Dibaeis

104a Ascospores pigmented, grey to brown --- 105
104b Ascospores colourless --- 107

105a Mazaedium present (the ascospores are discharged from the asci in early stage and ripen in a layer on top of the hymenium, which stains the finger when touched); ascocarps with lecanorine margin --- Tylophoron moderatum Nyl.
105b Mazaedium absent (the ascospores ripen in the asci and the ascocarps do not stain the finger when touched); ascocarp margin variable --- 106

106a Ascocarp margin lecideine --- Buellia (sensu lato)
106b Ascocarp margin lecanorine --- Rinodina

107a Ascospores without septa --- 108
107b Ascospores with one or more, transverse and sometimes also longitudinal, septa --- 120

108a Ascospores over 30 per ascus --- Acarospora/Biatorella
108b Ascospores 8 or less per ascus --- 109

109a Thallus squamulose, often on a felt-like hypothallus --- 110
109b Thallus crustose, continuous or areolate to granular --- 115

110a Squamules byssoid (consisting of loose hyphae), without cortex --- Crocynia
110b Squamules not byssoid, with cortex (with smooth upper side of compacted hyphae) --- 111

111a Photobiont green; felt-like prothallus present, pale to brown, or absent --- 112
111b Photobiont blue-green; felt-like prothallus present, black --- 114

112a Felt-like hypothallus present; thallus squamules with dull lower side (lower cortex absent), usually with raised tips, 0.5-2 mm long --- Phyllopsora
112b Felt-like hypothallus absent; thallus squamules with glossy lower side (lower cortex present) --- Eschatogonia

114a Asci with an apical I+ blue plug; hymenium I+ blue --- Parmeliella
114b Asci without apical plug or with I+ greenish plug; hymenium I+ blue-greenish, usually turning brown (expected)  --- Pannaria

115a (109) Spores over 50 mu long; ascocarps immersed in thallus warts (expected)  --- Pertusaria
115b Spores not over 30 mu long; ascocarps sessile --- 116

116a Ascocarp margin lecanorine --- Lecanora
116b Ascocarp margin biatorine or lecideine --- 117

117a Asci with I+ blue tholus --- 118
117b Asci with I-negative tholus, or with weakly I+ blue, tubular structure in tholus --- 119

118a Apothecia brown, K- --- Biatora (sensu latissimo)
118b Apothecia dark red, K+ dark violet --- Pyrrhospora

119a Hymenium I+ blue; on bark --- Malcolmiella
119b Hymenium I- (reddish); on loamy soil or stones on soil --- Trapelia

120a (107) Hymenium I+ blue to brownish, the colour concentrated inside and/or on outside of the ascus tips --- 121
120b Hhymenium I+ blue to reddish or absent, the colour restricted to the hymenial jelly or the ascospores, ascus tips unstained --- 148

121a Ascospores with transverse septa only --- 122
121b Ascospores with transverse and longitudinal septa (muriform) --- 141

122a Ascospores with single septum --- 123
122b Ascospores with several septa --- 126

123a Ascospore septa much thickened, usually about as thick as the lumina; disc often orange, K+ dark violet --- Caloplaca
123b Ascospore septa about as thin as outer wall --- 125

125a Asci without ocular chamber --- Catillaria
125b Asci with ocular chamber --- Catinaria

126a Ascocarp margin lecanorine; disc red (expected)  --- Haematomma
126b Ascocarp margin biatorine or lecideine; disc not red --- 127

127a Ascocarps without proper margin, this disappearing in early stage of development --- 128
127b Ascocarp margin clearly present, except in old apothecia deformed by age --- 129

128a Ascocarps semiglobose to globular; on rock, bark or moss --- Micarea
128b Ascocarps flat, on leaves (expected)  --- Byssolecania

129a Ascocarps with byssoid outer margin --- Byssoloma
129b Ascocarps with compact outer margin --- 130

130a Hymenial jelly present; asci and paraphyses sticking together and not easily separated unless by KOH-treatment --- 131
130b Hymenial jelly absent; asci and paraphyses free in water mounts --- Vezdaea

131a Tholus largely I+ blue with narrow I-negative axial mass --- Bacidia (sensu lato)
131b Tholus with I+ blue tubular structure --- 132

132a Apothecia mostly under 0.5 mm wide, soon convex, with paraplectenchymatic exciple --- Fellhanera
132b Apothecia to over 1 mm wide, remaining more or less flat, with prosoplectenchymatic exciple --- Badimia

141a (121) Campylidia grey, directly on thallus --- Calopadia
141b Campylidia yellow or brown, on whitish thallus warts --- Sporopodium

148a (120) Ascocarps with several, sometimes dot-like discs --- 149
148b Ascocarps with single discs (unless deformed) --- 153

149a Ascospores with thickened septa and rounded lumina, I+ brownish --- Glyphis cicatricosa Ach.
149b Ascospores with thin septa, I-negative --- 150

150a Ascocarps elongate, discs in rows --- Enterographa
150b Ascocarps rounded, discs not in rows --- 151

151a Discs dot-like, dark --- 152
151b Discs wider, pinkish to whitish pruinose --- Syncesia

152a Thallus not byssoid, composed of compacted hyphae --- Chiodecton
152b Thallus byssoid, composed of loose hyphae --- Dichosporidium

153a (148) Ascocarps sessile with constricted base, without algal margin --- 154
153b Ascocarps immersed in thallus or thallus warts --- 163

154a Ascocarps with carbonized (dark brown to black) parts in hypothecium and sometimes also in margin --- 155
154b Ascocarps without carbonized parts --- 159

155a Ascospores with thickened septa and rounded lumina, muriform --- Glyphis scyphulifera (Ach.) Staiger
155b Ascospores with thin septa and edged lumina, without or with transverse septa, rarely muriform --- 156

156a Ascocarps whitish pruinose --- 157
156b Ascocarps black or with yellowish- or reddish-pruinose disc --- 158

157a Ascocarps with thin margin, convex from an early stage --- Catarraphia dictyoplaca (Mont. et v.d.Bosch) Massal.
157b Ascocarps with thick, prominent margin, remaining flat for a long time (expected)  --- Lecanactis

158a Paraphyses easily free, scarcely branched except near the tips; tips swollen and with brown pigment; disc black --- Bactrospora
158b Paraphyses densely branched and not easily free, less distinct disc often yellow- or red-pruinose --- Cresponea

159a (154) Ascospores with single transverse septum; ascocarps usually yellow to orange --- Coenogonium
159b Ascospores with several septa, transverse and often also longitudinal --- 160

160a Thallus with ca. 1 mm long hairs --- Tricharia
160b Thallus without hairs, with scale-like or bristle-like hyphophores; photobiont cells rounded, separate --- Gyalideopsis

163a (153) Ascospores with thickened septa and rounded lumina, often I+ blue to violet --- 164
163b Ascospores with thin septa or without septa, I- or occasionally I+ pale blue --- 167

164a Ascocarps with carbonized parts --- 165
164b Ascocarps without carbonized parts --- 166

165a Carbonized parts in ring around hymenium and sometimes forming a central columella in the hymenium --- Ocellularia
165b Carbonized part mainly in hypothecium --- Phaeographis

166a Hymenium with thin proper exciple separated from thalline margin by a split and bearing periphyses --- Thelotrema
166b Hymenium not separated from thalline margin or without periphyses on proper exciple --- Myriotrema

167a Ascocarps surrounded by a raised thallus rim --- 168
167b Ascocarps surrounded by flat thallus or thallus rim not raised above the disc --- 169

168a Thallus rim around ascocarps lacerate --- Chroodiscus
168b Thallus rim around ascocarps smooth --- Echinoplaca

169a Ascocarps surrounded by a thallus rim to the level of the disc --- 170
169b Ascocarps without differentiated thallus rim --- 171

170a Thallus forming convex warts with scattered spines; foliicolous; ascocarp disc brownish --- Bullatina
170b Thallus continuous; foliicolous or not; ascocarp disc black --- Mazosia

171a Asci not embedded in proper hymenium with differentiated paraphyses and hymenial gelatine; ascocarps poorly differentiated, visible as whitish spots on the thallus --- Cryptothecia
171b Asci imbedded in proper hymenium with paraphyses and gelatine --- 172

172a Photobiont cells elongated and forming irregularly branching threads (Trentepohlia-like) --- 173
172b Photobiont cells rounded, isolated --- Echinoplaca

173a Ascospores transversely septate --- Arthonia
173b Ascospores muriform --- Arthothelium

200a (100) Ascospores with thickened septa and rounded lumina, often I+ blue-violet; paraphyses unbranched (family Graphidaceae) --- 201
NOTE: Provisionally the traditional generic division of the family Graphidaceae is followed here, although a new generic division is proposed by Staiger in 2002.
200b Ascospores with thin septa, I-negative; paraphyses usually densely branched and anastomosing --- 208

201a Ascocarps grouped in rounded or elongate groups surrounded by a matrix different from the thallus --- 202
201b Ascocarps solitary, linear or more or less richly branched --- 204

202a Ascospores remaining colourless --- Glyphis
202b Ascospores pale grey, turning dark brown when old --- 203

203a Spores transversely septate only --- Sarcographa
203b Spores muriform --- Sarcographina

204a Ascospores remaining colourless --- 205
204b Ascospores pale grey, turning dark brown when old --- 207

205a Ascocarps with raised margins including carbonized or non-carbonized excipular tissue; ascospores usually I+ dark brown-violet, sometimes I-negative --- 206
205b Ascocarps slit-like, without raised margins, or with swollen margins composed only of thallus tissue; ascospores I+ blue or pale blue, occasionally I-negative --- Fissurina

206a Ascospores with transverse septa only --- Graphis
206b Ascospores muriform --- Graphina

207a Ascospores with transverse septa only --- Phaeographis
207b Ascospores muriform --- Phaeographina

208a (200) Ascocarps with carbonized margin --- 209
208b Ascocarps without carbonized margin --- 210

209a Ascocarps with closed labia, at least when young, always elongate --- Opegrapha
209b Ascocarps always showing the disc, irregularly rounded to elongate --- Lecanographa

210a Ascocarps with carbonized hypothecium; ascospores spermatoid, ca. 40 x 3 mu, including ca. 25 mu long and 1 mu wide tail --- Graphidastra multiformis (Mont. & v.d.Bosch) Thor
210b Ascocarps completely uncarbonized; ascospores not spermatoid, over 5 mu wide --- 211

211a Ascocarps with lacerate thalline margins raised above the disc --- Chroodiscus
211b Ascocarps without thalline margin raised above the disc --- 212

212a Ascospores transversely septate only --- Arthonia
212b Ascospores muriform --- Arthothelium

250a (100) Ascospores without septum --- 251
250b Ascospores with one septum --- 253
250c Ascospores with several septa --- 257

251a Ascospores over 40 mu long; hymenium I+ blue; paraphyses clearly present --- Pertusaria
251b Ascospores under 40 mu long; hymenium I- or I+ red or I+ blue --- 252

252a Paraphyses present; hymenium I-negative --- Monoblastia pellucida Aptroot
252b Paraphyses indistinct; hymenium I+ blue or red --- Verrucaria

253a Ascospores grey --- Micromycothelia
253b Ascospores colourless --- 254

254a Asci with strongly decurrent tholus, reaching about the middle of the ascus, without ocular chamber; paraphyses indistinct --- Mycoporum
254b Asci with slightly decurrent tholus not extending beyond upper 20% of ascus, with or without ocular chamber; paraphyses distinct --- 255

255a Asci with ocular chamber surrounded by ring-like wall thickening; mainly corticolous --- 256
255b Asci without ring-like wall structure; mainly foliicolous --- Strigula

256a Ascospores over 70 mu long; campylidia frequent --- Musaespora
256b Ascospores under 50 mu long; campylidia absent --- Anisomeridium

257a (250) Paraphyses absent --- 258
257b Paraphyses present, distinct --- 260

258a Ascospores muriform; algal cells present in hymenium; thallus squamulose; on stone or bark --- Endocarpon
258b Ascospores transversely septate only; algal cells absent from hymenium; on leaves --- 259

259a Ascospores colourless --- Pocsia
259b Ascospores grey --- Microtheliopsis uleana Müll. Arg.

260a Ascospores colourless --- 261
260b Ascospores grey --- 267

261a Ascospore septa thin, lumina angular; asci with thin apical wall --- 262
261b Ascospore septa thick, lumina rounded; asci with thickened apical wall --- 264

262a Ascospores transversely septate only --- Porina
262b Ascospores muriform --- 263

263a Thallus medulla yellow --- Myeloconis erumpens P.M. McCarthy & Elix
263b Thallus medulla whitish --- Clathroporina

264a Ascospores transversely septate only --- 265
264b Ascospores muriform --- 266

265a Perithecia in groups with fused ostioles (expected) --- Astrothelium
265b Perithecia single or in groups, then with separate ostioles --- Trypethelium

266a Perithecia in groups with fused ostioles --- Laurera
266b Perithecia single or in groups, then with separate ostioles --- Cryptothelium

267a (260) Ascospores muriform, with thin septa --- Anthracothecium
267b Ascospores transversely septate or muriform, with thickened septa and rounded lumina --- Pyrenula

290a (99) Thallus squamulose, composed of scale-like compartments which are more or less raised and rarely exceed 1-2 mm --- 292
290b Thallus crustose in strict sense --- 300

292a Squamules byssoid, without cortex (consisting of loose hyphae) --- Crocynia
292b Squamules not byssoid, with cortex (with smooth upper side of compacted hyphae) --- 293

293a Squamules bluish grey, with papillose cortex cells; felt-like prothallus absent --- Psoroglaena
293b Squamules greenish grey, without papillose cortex; felt-like prothallus present --- 294

294a Photobiont green; felt-like prothallus pale to brown, or absent --- 295
294b Photobiont blue-green; felt-like prothallus black --- not identifiable to genus level without ascocarps

295a Felt-like hypothallus present; thallus squamules with dull lower side (lower cortex absent), usually with raised margins --- Phyllopsora
295b Felt-like hypothallus absent; thallus squamules with glossy lower side (lower cortex present) --- Eschatogonia

300a (290) Conidangia present, thalloid propagules absent --- 301
300b Conidangia absent, thalloid propagules present (soredia, isidia, schizidia, etc.) --- 350
300c Conidangia and thalloid propagules both absent --- not treated

301a Conidangia largely immersed in the thallus, recognizable as coloured spots or as swellings of the thallus --- 302
301b Conidangia with strongly exerted, at least about 0.5 mm long, flattened or cylindrical part --- 304

302a Conidangia visible only as low, irregular, slightly paler swellings on a smooth, continuous, greenish, varnish-like thallus; conidia variable, usually rod-shaped --- Coenogonium
302b Conidangia with distinct, usually brown or black, pore, or more widely opened; thallus different --- 303

303a Conidangia widely opened --- Bacidia (sensu lato)
303b Conidangia immersed and visible by their ostiole only --- not treated

304a Conidangia with elongate, thorn-like extension --- 305
304b Conidangia with flattened, more or less ear- or leaf-shaped extension --- 306

305a Extension tube-like, ca. 0.5-1 mm long and 0.05 mm diam.; thallus a thin, pale crust with black perithecia --- Anisomeridium throwerae R.C. Harris
305b Extension solid, producing conidia in a lateral gelatinous mass --- Echinoplaca, Tricharia

306a Extension ear-shaped, with wide base sitting on the thallus or on a thallus wart (campylidium); conidia produced in cavity at the base --- 307
306b Extension leaf-shaped, with a cylindrical basal part and a flattened, often dentate upper part (hyphophore); conidia produced in gelatinous clump attached in flattened part --- Echinoplaca, Gyalideopsis

307a Extension sitting directly on the thallus, grey --- Calopadia, Tapellaria
307b Extension sitting on a thallus wart --- 308

308a Extension brown or yellow; foliicolous --- Sporopodium
308b Extension grey; corticolous --- Musaespora

350a (300) Isidia present --- 351
350b Schizidia present, rounded, produced on top of low warts; on trunks in forest --- Stegobolus berkeleyanus Mont.
350c Soredia or goniocysts present (few species treated) --- 355

351a Isidia cylindrical; thallus green; on bark in forest --- 352
351b Isidia cup-shaped; thallus yellowish; on leaves in forest --- Porina mirabilis Lücking & Vezda

352a Thallus distinctly lobed, with lobes free from substrate at their tips --- 353
352b Thallus completely attached, with indistinct margin; on bark in forest --- 354

353a Photobiont green; thallus much divided in scattered squamules --- Phyllopsora
353b Photobiont blue-green; thallus lobed and rosette-like (expected) --- Parmeliella brisbanensis (Knight) P.M. Jørg. & D. Galloway

354a Isidia thin and glossy; thallus smooth, green --- Porina tetracerae (Ach.) Müll. Arg.
354b Isidia thick and byssoid; thallus byssoid, pale green --- Dichosporidium

355a (350) Thallus completely composed of soredia or granules --- 356
355b Thallus with delimited soralia or goniocystangia --- 358

356a Thallus bright yellow; soredia ca. 50 mu diam. --- Chrysothrix xanthina (Vain.) Kalb
356b Thallus greenish or greyish --- 357

357a Granules with feltlike surface, at the thallus margins coagulated in small lobules; C- --- Lepraria
357b Granules with smooth surface, equally dispersed; C+ orange --- Pyrrhospora quernea (Dicks.) Körb.

358a Soralia yellow; thallus green; in forest --- Myeloconis erumpens P.M. McCarthy & Elix
358b Soralia greyish --- 359

359a Soredia coarse, mixed with granules and globular isidia/pustules --- Diorygma rufopruinosum (A.W.Archer) Kalb, Staiger & Elix
359b Soredia fine-grained, of equal size --- 360

360a On tree bark; thallus thin, dark green, varnish-like, largely covered by fine-grained soralia; black ascocarps regularly present --- Amandinea efflorescens (Müll. Arg.) Marbach
360b On road banks; large, indistinct thalli with scarce, rounded soralia (expected) --- Dibaeis sorediata Kalb & Gierl