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Key to the Lichen Genera of the Guianas
by Harrie Sipman, Botanical Museum Berlin-Dahlem
Revised June 1996
The key deals with c. 190 genera known from or expected in the three Guianas (Guyana, Surinam, French Guiana). Included are all genera known from literature or from recent, unpublished collections. Genera in " " concern provisional identifications or taxa of uncertain or provisional taxonomic position. Genera in [ ] are known from surrounding areas and expected for the Guianas.
The genera Cladia, Cladina, and Cladonia may now be keyed to species using the Key to the Cladoniaceae of the Guianas, by Ted Ahti and Harrie Sipman, 1997.
Basic knowledge of lichens is required for use of the key. For easier use a simplified terminology is applied. e.g., all interascal filaments are called paraphyses.
Although the key is principally meant for the Guianas, it is likely to be of use throughout the Amazon basin, and genera recorded from that area are included as much as possible.
N.B. The number series of the couplets is incompletely used, because numbers are reserved for future extensions. Interrupted sites are marked by three blank lines.
The following persons are gratefully acknowledged for contributions: R. C. Harris (1986), L. Brako (1986) , J. Knoph (1986), A. Aptroot (1996). Errors are my own responsibility!
Additions, corrections, recommendations are very welcome! Please contact Harrie Sipman, who would appreciate such cooperation very much. E-mail: h.sipmanbgbm.org. Please address inquiries about the presentation of this key and about the Smithsoniam Institution's Biological Diversity of the Guianas Program to Sara Alexander by E-mail: alexandersarsi.edu.
la Thallus fruticose, i.e. with free-standing or hanging, terete or flattened, often branched lobes, which may measure a few mm to several dm in length, and which are affixed only at their base, rather uniformly colored on all sides; in addition, squamulose or crustose thallus may be present 2 b Thallus foliose, i.e. forming a flat plate, measuring usually several cm in diam., more or less deeply divided into lobes, which grow usually parallel to their substrate, usually rather closely appressed to it, often attached by tomentum or rhizines on the lower side, so that the whole thallus can usually be lifted off easily; the lower side mostly differing markedly in color from the upper side, often brownish or black 20 c Thallus squamulose, i.e. at first sight seeming crust- like, but composed of flat, generally separate lobes, rarely exceeding 1-2 mm in length, which grow more or less parallel to the substrate, attached to it by their base or by their underside, not by rhizines, so that the thallus cannot be lifted off without breaking into separate lobes; their lower side usually differing markedly in color from the lower side, often whitish 80 d Thallus crustose, i.e. forming a layer which covers the substrate and is affixed to it with its whole lower side, in such a way that it cannot be lifted off, sometimes penetrating into the substrate or even developed inside the substrate (e.g. endophloeodic: growing inside the (outer) bark cells) 100 2a (fruticose) Thallus branches with central cavity 3 b Thallus branches solid, with arachnoid or more compact central tissue 8 3a Thallus surface glossy, pale brown to brown, with usually frequent perforations; terrestrial, occasionally on mossy tree trunks Cladia b Thallus surface dull, usually whitish, greenish or greyish; perforations in most species absent, in some species present in axils of ramifications (rarely more frequent, than thallus yellowish) 4 4a Thallus branches with squamules, especially at the base Cladonia b Thallus without such appendages 5 5a Rare epiphytic species, known only from Mt. Roraima at c. 2000 m (widespread and common in the Andes) Oropogon b Widespread terrestrial species, mostly on white sand, occasionally on decaying tree stumps 6 6a Thallus surface slightly felty, without cortex (Cladonia signata would also key out here) Cladina b Thallus surface smooth, with thin cortex Cladonia 8a Thallus branches with tough central stand, which becomes visible between the breaking outer layer by moderate tension Usnea b Thallus branches without tough central strand, breaking completely by tension 9 9a Epiphytic species, occasionally on decorticated wood 10 b Saxicolous species, occasionally on thin soil cover on rock 15 10a Lobes applanate, over two times wider than thick 11 b Lobes more or less terete 12 11a Thallus greenish grey, over 2 cm long when full-grown, often pendant Ramalina b Thallus whitish, c. 1 cm long when full-grown, erect Siphula 12a Thallus, at least in part, yellow, reaction K+ purple Teloschistes b Thallus bluish grey or greenish to whitish yellow, K- 13 13a Thallus bluish grey to black, basal branches sometimes whitish; branches more or less terete; with bluegreen algae 14 c Thallus whitish yellow; branches flattened, composed of chains of apothecia; with green algae Polystroma 14a Richly branched; main branches over 0.1 mm wide, with more or less scattered tomentum; no apothecia; with multilayered cortex; algae Nostoc in glomerules, not gelatinous Dendriscocaulon b Richly branched; main branches up to 0.1 mm wide, without tomentum; apothecia common (upland); cortex composed of a single cellular layer; algae Scytonema, gelatinous Polychidium c Sparingly branched; main branches over 0.1 mm wide, without tomentum; apothecia common; no cellular cortex; algae Nostoc in chains, gelatinous Lempholemma 15a Fruticose thallus with granular or squamulose appendages; with green algae Stereocaulon b Fruticose thallus without such appendages; algae bluegreen or green 16 16a On rock; thallus composed of brownish to blackish, fruticose parts only; ascomycetes, though rarely fruiting 17 c On soil; fruticose thallus yellowish, without algae; in addition, crustose, algiferous, dark green thallus present; basidiomycete Multiclavula 17a On temporarily submersed rocks in streams; thallus gelatinous, black; rare species 18 b On mostly dry rock faces on land; thallus not gelatinous, white or grey; common species 19 18a Lobes flat, little branched, over 1 cm long Jenmania b Lobes rounded and richly branched, forming cushions less than 1 cm thick Lichina? 19a Thallus dark brown to black; algae bluegreen; on granite Peltula b Thallus white to pale grey; algae green; on sandstone (cf. also Toninia, with thallus composed of rounded, sometimes rather elongated, warts; recognizable by dark grey color and frequent presence of apothecia) Siphula 20a (1, foliose) Lobes with thread-like appendages (rhizines) on lower side; algae green 21 b Lobes with tomentum on lower side, at least on part of it; algae mostly bluegreen 41 c Lobes with naked lower side; algae various 61 21a Thread-like appendages on the margins of the lobes (cilia), sometimes also on underside (rhizines) 22 b Thread-like appendages not on the margins of the lobes, only on underside (rhizines) 31 22a Cilia with inflated base 23 b Cilia without inflated base 24 23a Upper side of thallus yellowish green, usnic acid present Relicina b Upper side of thallus whitish grey, atranorin present Bulbothrix 24a Rhizines white or grey, sometimes black, but then usually with perpendicular side branchlets; lower side often without cortex, felty; spores biloculate, dark Heterodermia b Rhizines black; lower side always with cortex, smooth; spores uniloculate, colorless 25 25a Rhizines one or more times dichotomously branched Hypotrachyna b Rhizines mostly unbranched, or in part irregularly branched 26 26a Thallus lobes elongate, mostly under 2 mm wide Parmelinopsis b Thallus lobes short and wide, mostly over 5 mm wide 27 27a Underside near lobe tips without rhizines, naked in a several mm wide zone Parmotrema b Underside rhizinate to the margin 28 28a Underside near margin brown, with scattered rhizines of variable length Rimelia b Underside near margin pale, with dense, short rhizines mixed with scattered longer ones (not yet known from the Guianas) Rimeliella 31a Rhizines absent from marginal zone; thallus lobes wide, often over 10 mm wide Parmotrema b Rhizines present till lobe margins; thallus lobes usually up to 2 mm wide, rather narrow and deeply dissected 32 32a Rhizines frequently dichotomously branched Hypotrachyna b Rhizines mostly unbranched or a few times irregularly branched 33 33a Apothecia completely black, without grey thalline margin when well developed Pyxine b Apothecia with grey thalline margin 34 34a Spores biloculate, grey to brown; lower side whitish or black, sometimes without cortex 35 b Spores uniloculate, hyaline; lower side brown to black, always with cortex 37 35a Thallus applanate; cortex composed of periclinally arranged hyphae 36 b Thallus more or less ascendant; cortex composed of longitudinally arranged hyphae, surface slightly longitudinally striate Heterodermia 36a Apothecia with pale hypothecium; thallus without divaricatic acid, with dull, black or pale, lower cortex Physcia b Apothecia with dark hypothecium; thallus of Guianan species always with divaricatic acid, with glossy, black lower cortex Dirinaria 37a Epiphytic or epilithic; thallus whitish grey, without usnic acid 38 b Epilithic; thallus yellowish green, with usnic acid Xanthoparmelia 38a Lower surface pale brown to brown; spores less than 10 µm long Pseudoparmelia b Lower surface dark brown to black; spores over 10 µm long Canoparmelia 41a Thalli with small, rarely over 5 mm wide, lobes, usually closely appressed; algae always bluegreen 42 b Thalli with usually large, over 5 mm wide lobes, not or loosely appressed; algae bluegreen or green 46 42a Upper surface tomentose; tomentum on lower side often restricted to marginal patches; uncommon Erioderma b Upper surface glabrous; tomentum on lower side usually spread over most of the thallus 43 43a Cortex composed of longitudinally arranged hyphae; thallus often with concentric ridges; apothecia without thalline margin Coccocarpia b Cortex not composed of longitudinally arranged hyphae; thalli without concentric ridges 44 44a Thallus closely appressed to substrate 45 b Thallus loosely appressed with ascending margins; uncommon Leioderma 45a Thallus without distinct prothallus; apothecia always with thalline margin Pannaria b Thallus with distinct, often tomentose, prothallus; apothecia with or without thalline margin Parmeliella 46a Thallus with small, sharply delimited, raised or immersed white or yellow, tomentum-free spots on lower side 47 b Thallus with larger, not sharply delimited, pale, tomentum-free areas on lower side Lobaria 47a White spots on lower side, with prominent, raised margin (cyphellae) Sticta b Yellow spots on lower side, with margin hardly raised above the center (pseudocyphellae) Pseudocyphellaria 61a Thallus of felty structure 62 b Thallus compact, usually with differentiated cortical layer 63 62a With bluegreen algae, without ascocarps (basidiolichen); thallus usually growing parallel to substrate Dictyonema b With Trentepohlia algae, apothecia sometimes present; thallus often growing at right angles to substrate Coenogonium 63a Thallus scarcely dissected, lobes + hemispherical; basidiolichens without ascocarps 64 b Thallus strongly dissected, lobes usually much longer than wide; apothecia often present 65 64a Thallus concentrically ridged, with bluish color Dictyonema b Thallus smooth with raised margin, with dark greenish Corella 65a Thallus bluegrey to black, gelatinous; algae Nostoc in chains; no cellular cortical layer Collema b Thallus bluegrey to black, gelatinous; algae Nostoc in chains; cortical layer one cell thick 66 c Thallus whitish grey to greenish grey, not gelatinous; algae green; cortex well developed, several cells thick 67 66a Spores septate; thallus often under 0.5 mm thick Leptogium b Spores simple; thallus over 0.5 mm thick Physma 67a Spores dark, biloculate and ovate; underside black, with cortex 68 b Spores colorless, pluriloculate and bacillar; underside white, without cortex Physcidia 68a Apothecia, at least when well developed, without thalline margin Pyxine b Apothecia with persistent thalline margin 69 69a Apothecia with dark hypothecium; thallus lobes elongate and laterally confluent Dirinaria b Apothecia with pale hypothecium; thallus lobes not laterally confluent Hyperphyscia 80a (1, squamulose) Perithecia present; spores muriform; algae present in hymenium Endocarpon b Perithecia (rarely) present; spores transversely septate: no algae in hymenium Normandina c Apothecia present, or fruitbodies absent 81 81a Squamules + rounded, whitish with raised margin, ca. 1 mm diam.; fruitbodies unknown (parasitic (?) perithecia sometimes present; spores transversely septate; no algae in hymenium) Normandina b Squamules usually elongated and greenish, without raised margin 82 82a Squamules on a felty layer of hyphae (prothallus) 83 b Squamules directly on substrate, sometimes with prothallus penetrating into the substrate, but not forming a layer over the substrate 91 83a Algae bluegreen 84 b Algae green 85 84a Thallus without prothallus; apothecia always with thalline margin Pannaria b Thallus with distinct, often tomentose, prothallus; apothecia with or without thalline margin Parmeliella 85a Hymenium IKI+ orange [Opegraphaceae] (probably undescribed genus, known so far from Neblina, Venezuela) b Hymenium IKI+ blue 86 86a Upper surface of squamules byssoid, lacking cortex and woolly by free hyphae Crocynia b Upper surface of squamules more or less smooth, sometimes pruinose, cortex present 87 87a Squamules with an upper and lower cortex comprised of a thin layer of cubic cells Eschatogonia b Squamule cortex otherwise, lower cortex usually absent 88 88a Spores generally over 25 µm, transversely multiseptate Squamacidia b Spores generally under 25µm, 1-2-loculate Phyllopsora 91a Algae bluegreen Peltula b Algae green 92 92a Squamules greenish above, whitish below, usually elongate (primary thallus squamules of Cladonia may key out here) "Biatora" b Squamules whitish grey on both sides, elongate and erect Siphula c Squamules whitish grey on both sides, usually roundish 93 93a Apothecia stalked and raised above the squamules, usually on branched pseudopodetia Stereocaulon b Apothecia sessile between the squamules Toninia(s.l.) 100a (1, crustose) Foliicolous species, found on living leaves 101 b Corticolous, terrestrial or saxicolous species 200 101a (foliicolous) Thallus with dish-like, stalked isidia; ascocarps unknown Porina (Phyllophiale) b Thallus naked or with somewhat hair-like hypophores with flattened tips, producing conidia 102 c Thallus with c. 0.1-2 mm long, sterile bristles/hairs 170 102a Apothecia present, rounded 103 b Lirellae present, elongate with black, distinctly carbonaceous labiae Opegrapha c Perithecia present 150 d Ascocarps absent, but conidangia present 180 e Black-rimmed goniocystangia resembling ascocarps, but producing goniocysts, present Opegrapha gr. lambinoni 103a Ascocarps (seemingly) without excipular tissue, without visible margin 104 b Ascocarps with clearly differentiated margin 110 104a Fruitbodies white, with asci scattered in loose, hyphal tissue; spores muriform 105 b Fruitbodies usually colored, compact, with asci in distinct, gelatinous hymenium 106 105a Spores muriform Cryptothecia b Spores transversely septate only Stirtonia 106a Paraphyses straight; spores transversely septate; asci with I+ blue tholi; hymenium I+ blue Byssolecania b Paraphyses branched and anastomosing; asci with I- negative tholi; hymenium I+ red or blue 107 c Paraphyses branched and anastomosing; asci with I- negative tholi; hymenium I-negative 110 107a Spores transversely septate 108 b Spores muriform Arthothelium 108a Conidia filiform, over 50 µ m long, produced in elongate pycnidia with lateral pore Eremothecella b Conidia bacillar, under 20 µ m long, produced in rounded pycnidia with apical pore Arthonia 110a Apothecia immersed in the thallus, disc level with thallus surface, sometimes surrounded by a raised thalloid margin 111 b Apothecia adnate to sessile, often constricted at the base; disc above thallus surface 115 111a Thallus with cortical layer of quadratic, rectangular or rounded cells, one cell-layer thick 112 b Thallus without cortical layer or with a cartilaginous cortical layer 113 112a Spores transversely septate; epithecial algae absent Asterothyrium b Spores muriform; epithecial algae present Gyalectidium 113a Paraphyses simple; with splitting, erect or recurved, thalline margin Chroodiscus b Paraphyses branched and anastomosing; without thalline margin 114 114a Spores bicellular; hyphophores stalked Echinoplaca b Spores at least 3-septate; hyphophores without stalk, consisting of a sessile, gelatinous ball Actinoplaca 115a Hymenium I+ blue, at least near the asci; asci I+ blue, usually in the tholus, at least along the outside 116 b Hymenium I+ reddish; asci I-negative Mazosia c Hymenium and asci I-negative or very pale blue 135 116a Spores simple 117 b Spores transversely septate only 118 c Spores muriform 126 117a Thallus smooth, containing green algae; apothecia with pronounced margin "Lecidea" gr. piperis b Thallus granular, containing bluegreen algae; apothecia soon convex and immarginate "aff. Leprocollema?" 118a Excipulum formed externally by loose, felty hyphae, which surround the apothecia as a thin circle Byssoloma b Excipulum compact, also externally 119 119a Asci with a I+ blue tubular structure in the tholus 120 b Asci without tubular structure, with or without a I+ blue axial mass 121 120a Apothecia usually over 0.5 mm wide, flat; I-positive tubular structure in ascus apex distinctly stained over its whole length; excipulum usually filled with crystals Badimia b Apothecia mostly under 0.5 mm side, soon convex; I-positive tubular structure in ascus apex most distinctly stained in its basal part; excipulum not filled with crystals Fellhanera 121a Campylidia never present; asci with conical or rounded, I+ pale blue axial mass 122 b Campylidia (usually) present; asci without I+ pale blue axial mass 123 122a Asci with conical axial mass; excipulum prosoplectenchymatic Bacidia b Asci with rounded axial mass; excipulum paraplectenchymatic Woessia (incl. Bacidina) 123a Hypothecium purplish; apothecia black, sometimes with white pruina Tapellaria b Hypothecium usually not purplish; apothecia variously colored 124 124a Ascospores 3-septate, fusiform 125 b Ascospores 7-septate, bacillar; campylidia as in Calopadia "Tapellariopsis" c Ascospores multiseptate, over 10-septate, acicular; no campylidia Bapalmuia 125a Campylidia producing flask-shaped, c 20 µm long conidia Barubia b Campylidia producing ovoid, c. 10 µm long conidia Loflammia 126a Margin of apothecium with long, stiff hairs Lasioloma b Margin of apothecium without such hairs 127 127a Epithecial algae present Sporopodium b Epithecial algae absent 128 128a Apothecia black, sometimes with white pruina, with flat disc; hypothecium purplish Tapellaria b Apothecia dark brown, with flat disc Calopadia c Apothecia red to carmine, with flat disc Loflammia d Apothecia yellowish, soon convex Logilvia 135a Apothecia elongate to angular or round, not constricted at base, margin formed by a dark tissue which originally covers the disc Aulaxina b Apothecia round to slightly irregular, margin not formed by a dark tissue which originally covers the disc 136 136a Apothecia proliferating on their margins; mainly on leaf margins Polystroma b Apothecia not proliferating on their margins 137 137a Paraphyses simple, straight 138 b Paraphyses branched and anastomosing 139 138a Apothecia yellow; spores bicellular in cylindrical asci (NB: for species determination it is important to look for the pyncidia, which are often found on separate plants) Dimerella b Apothecia variously colored; spores variously septate in clavate asci Gyalidea 139a Excipulum thinly spreading laterally over the thallus Echinoplaca b Excipulum not spreading, forming a prominent margin 140 140a Without bristle-like hyphophores Gyalideopsis b With bristle-like hyphophores Actinoplaca 150a Thallus subcuticular, very glossy (incl. Phylloporis, Raciborskiella) Strigula b Thallus epicuticular, forming a usually dull sheet over the cuticula of the leaf 151 151a Perithecia smooth 154 b Perithecia with warts, bristles or a disc-like expansion around the pore; spores transversely septate or muriform 152 152a Perithecia whitish, with a disc-like extension around the pore or with more scattered scales Aspidothelium (included in Thelenella) b Perithecia reddish or black, with bristle-like extensions, usually in a whirl around the pore 153 153a Asci bitunicate; spores 14-17 x 3-4 µm, 3-septate Lyromma b Asci thinwalled; spores usually over 18 µm long Porina 154a Spores pale grey-brown, transversely 3-septate Microtheliopsis b Spores colorless, transversely septate or muriform 155 155a Spores two-celled 156 b Spores transversely pluriseptate 157 c Spores muriform 158 156a Spores under 30 µm long Anisomeridium b Spores over 50 µm long Musaespora 157a Ascocarps solitary Porina b Ascocarps grouped in raised thallus parts "Flavobathelium" 158a Perithecia with outer wall containing dark- brown pulveraceous masses, often irregularly shaped Phyllobathelium b Perithecia with outer wall without such masses, regular 159 159a Spores lumbricoid, with few longitudinal cells Phylloblastia b Spores oval, with numerous longitudinal cells Thelenella 170(101) (Sterile, hairy plants cannot be identified with certainty; they are arranged artificially under Tricharia melanothrix Fée, with black hairs, and T. leucothrix Fée, with white hairs) a Apothecia immersed, disc level with thallus surface, sometimes surrounded by a raised, rim-like thallus area 171 b Apothecia sessile, often constricted at the base 178 171a Hairs white. often over 1 mm long 172 b Hairs brown to black, short, under 0.2 mm 177 172a Perithecia present; hairs tiny, on the perithecia Porina b Apothecia present; hairs mostly on the thallus 173 173a Hairs tiny, dense, forming tomentose areas on the thallus and thalloid apothecial margins Mazosia b Hairs larger, often over 1 mm long, bristle-like 174 174a Thallus with cortical layer of quadratic, rectangular or rounded cells, one cell-layer thick 175 b Thallus without cortical layer or with a cartilaginous cortical layer 176 175a Spores transversely septate; epithecial algae absent Asterothyrium b Spores muriform; epithecial algae present Gyalectidium 176a Ascocarps surrounded by a raised thalloid rim Calenia b Ascocarps without raised thalloid rim, with a more or less distinct excipulum Echinoplaca 177a Ascocarps without black proper margin Caleniopsis b Ascocarps with black proper margin Aulaxina 178a Excipulum laterally spreading over the thallus, thus apothecia seemingly immarginate Echinoplaca b Excipulum not laterally spreading, apothecia distinctly marginate Tricharia 180a campylidia present: greyish or yellowish ear-like structures which are strongly raised on one side, and produce conidia: various species of Badimia, Loflammia, Sporopodium, not identifiable without apothecia; artificially arranged in the genus Pyrenotrichum 181 b hygrophores or other brush-like conidiogenous structures 186 c immersed or slightly exserted conidangia, black or concolorous with thallus 188 181a Campylidia producing ovoid, pyriform, simple or uniseptate conidia 182 b Campylidia producing flask-shaped, non-septate conidia Barubia c Campylidia producing filiform, septate, sometimes branched conidia 184 182a Campylidia producing uniseptate conidia with unequal cells; usually found with ascomata Byssoloma b Campylidia producing simple conidia 183 183a Campylidia short, on top of a thalloid cylinder; algae between the conidiophores Sporopodium b Campylidia not on thalloid cylinder; no algae between the conidiophores (Loflammia and Logilvia have similar campylidia, but are unlikely to be found without ascomata) Musaespora 184a Campylidia with branched, somewhat star-shaped conidia Lasioloma b Campylidia with unbranched conidia 185 185a Campylidia with cylindrical, to c. 40 µm long conidia without appendages Arthonia b Campylidia with cylindrical, c. 100 µm long conidia with appendages Badimia c Campylidia with tapering, c. 50 µm long conidia without appendages (genera to be separated by ascoma characters) Calopadia/Tapellaria 186a True hyphophores present, producing conidia in a free-hanging gelatinous ball Echinoplaca b Conidia not produced in a free-hanging gelatinous ball, but in a conidangium inside the brush-like structure 187 187a Conidangia brown to black, star-like branched; on leaf upper surface Lyromma b Conidangia pale brown, simple; on leaf margin Woessia 188a Conidangia black 189 b Conidangia pale, inconspicuous Dimerella 189a Conidia simple Anisomeridium b Conidia septate 190 190a Conidangia separate Strigula b Conidangia in groups of c. 10-30 in elevated thallus areas Phyllobathelium 200a (100, crustose, non-foliicolous lichens) Ascocarps present 201 b Ascocarps and conidangia absent; usually sterile crustose lichens; only a selection of common and characteristic species treated 401 c Ascocarps absent, conidangia present 450 201a Ascocarps rounded, with open disc (apothecia), immersed, sessile or stalked 202 b Ascocarps closed, with porus (perithecia), immersed or sessile 300 c Ascocarps elongate, with open or slit-like disc (lirellae), immersed or sessile 350 202a Apothecia covered by powdery, staining masses of spores ripening in a layer above the asci (mazaedia); apothecia sessile or sometimes on long, thin stalks (Caliciales) 203 b Apothecia not covered by spore masses, not staining, releasing spores from each ascus separately, immersed or sessile, rarely stalked 210 203a Apothecia pin-shaped, with up to 2 mm long, thin stalk; spores simple, pale brown 204 b Apothecia sessile 205 204a Apothecia black; spores two-celled, dark brown Calicium b Apothecia brownish; spores simple, pale brown Chaenotheca 205a Apothecia without thalline margin 206 b Apothecia with thalline margin 207 206a Spores two-celled Pyrgidium b Spores four-celled Pyrgillus 207a Spores two-celled Tylophoron b Spores four-celled Schistophoron 210a Hymenium I+ blue, at least near asci; asci I+ blue, at least along their outside, and usually also in their tips; paraphyses usually straight and unbranched, except near the tips, rarely branched and anastomosing; spores simple or variously septate, with rather equal cells (Lecanorales) 211 b Hymenium I+ red or blue; asci I-negative, except sometimes for a small, I+ blue ring around the ocular chamber; paraphyses densely branched and anastomosing; spores variously- septate but not simple, often with a single, much larger cell terminally or (sub)medially (Opegraphales, Arthoniales) 260 c Hymenium I-negative, rarely pale blue; asci I-negative or very pale blue throughout; paraphyses straight and unbranched, except sometimes near the tips, rarely branched and anastomosing; spores variously septate but not simple, with rather equal cells (terminal spore parts may still lack septation in young spores) (Gyalectales, Graphidales) 280 211a Spores grey to brown, at least when old, usually bicellular 212 b Spores persistently hyaline, various 214 212a Spore septa thin, lumina cubical; pycnidia bacillar, up to 5.5 µm long Buellia b Idem; pycnoconidia filiform, curved, up to 30 µm long [Amandinea] c Spore septa thickened, lumina rounded or more complicated 213 213a Apothecial margin without algae, concolorous with the disc; spores with thin-walled, rather pointed poles Hafellia b Apothecial margin with algae, usually concolorous with thallus; spores usually with thickened polar walls, not pointed Rinodina 214a Spores simple 215 b Spores transversely septate only 230 c Spores muriform 250 215a Apothecial margin lecanorine, of same color as thallus, with algal layer 216 b Apothecial margin lecideine or biatorine, of same color as disc, without algal layer, or apothecia without distinct margin 220 216a Spores under 20 µm long 217 b Spores over 30 µm long 218 217a Spores 8/ascus Lecanora b Spores many/ascus Maronina 218a Disc often punctiform, ascocarps often in compound groups immersed in warts; spores thick-walled and generally over 50 µm long Pertusaria b Disc open, apothecia separate; spores under 50 µm long Ochrolechia 220a Apothecial disc bright red, K+ purplish Pyrrhospora b Apothecial disc not bright red, usually brown or black, K- 221 221a Spores more than 16 per ascus, small and globose Piccolia b Spores fewer than 16 per ascus, never globose 222 222a Paraphyses anastomosing; exciple absent or indistinct; apothecia soon convex and globular [Micarea] b Paraphyses not anastomosing; exciple present, usually obvious in young apothecia at least; apothecia often flat 223 223a Algae bluegreen; thallus slightly gelatinous; on periodically inundated rock "Psorotichia" b Algae green; thallus not gelatinous; substrate various 224 224a Asci with strongly I+ blue tholus, in which a paler axial mass may be present 225 b Asci with weakly I+ blue tholus, in which an I+ blue central tube may be present "Lecidea" gr. piperis 225a Apothecia dark brown to black; thallus whitish or greenish, often K+ yellow or C+ orange; mostly on tree bark [Lecidella] b Apothecia pink or brownish to blackish discolored; thallus gray, granular, K-, C+ red; on burnt or decaying worked wood Trapeliopsis c Apothecia variously colored; thallus reactions different; mostly on tree bark Biatora s.l. 230a Apothecia with distinct margin of same color as thallus, with algae 231 b Apothecia with margin of different color as thallus, usually of same color as disc, or without distinct margin 234 231a Apothecia sessile with constricted base, with entire or crenulate margin; disc red, K+ purplish 232 b Apothecia immersed, with lacerate, erect margin; disc grey to pale brown, often white-pruinose Phlyctella 232a Spore septa thickened, about as thick as lumina; spores ovoid to fusiform, less then 5 times as long as wide 233 b Spore septa thin; spores bacillar, over five times as long as wide Haematomma 233a Spores two- to four-celled Caloplaca b Spores more than four-celled Letrouitia 234a Apothecia without distinct margin, very soon globose [Micarea] b Apothecia with a distinct margin, at least when young 235 235a Spores 2-loculate 236 b Spores 3- or more-loculate 240 236a Spores 2/ascus, over 40 µm long Lopezaria b Spores 8/ascus, under 30 µm long 237 237a Asci with ocular chamber surrounded by I+ weakly staining, rounded axial mass (Lecanora-type); spores halonate; exciple with well-defined cortical and medullary parts, but lacking algae "Megalaria" b Asci without rounded, I+ weakly staining axial mass around ocular chamber; spores not halonate; exciple compact 238 238a Ascus tholus containing a conical, I+ weakly staining axial mass around ocular chamber Biatora s.l. b Ascus tholus containing a tubular, I+ strongly staining structure; apothecia yellowish "Catillaria" s.l. 240a Spores extremely large, broad ellipsoid, 70-140 x 25-35 µm, 1/ascus Megalospora b Spores smaller or long fusiform or filiform, usually 8/ascus 241 241a Apothecia with weak, soon inapparent margin; apothecia soon convex to globose; paraphyses branched [Micarea] b Apothecia with prominent, rather persistent margin; disc more or less flat; paraphyses unbranched for most of their length, rarely (in Fellhanera) branched 242 242a Ascus tholus containing a more or less conical, I+ weakly staining axial mass around ocular chamber 243 b Ascus tholus containing a tubular, I+ strongly staining structure 245 243a Spores acicular, generally more than 5 times as long as wide 244 b Spores fusiform, less than 5 times as long as wide Biatora s.l. 244a Excipulum paraplectenchymatic; asci with rounded axial mass Woessia (Bacidina) b Excipulum prosoplectenchymatic; asci with conical axial mass Bacidia 245a Excipulum with byssoid outer layer Byssoloma b Excipulum smooth outside 246 246a Apothecia usually over 0.5 mm wide, flat; I-positive tubular structure in ascus apex distinctly stained over its whole length Badimia b Apothecia mostly under 0.5 mm side, soon convex; I- positive tubular structure in ascus apex most distinctly stained in its basal part Fellhanera 250a Apothecia yellow, K+ dark purple 251 b Apothecia not yellow, K- 252 251a Thallus white Brigantiaea b Thallus green suffused more or less with yellow Letrouitia 252a Ascus tholus containing a tubular I+ strongly staining structure; no campylidia present; paraphyses little branched Lopacidia b Ascus tholus without tubular, I+ structure, often with wide ocular chamber; usually campylidia present; paraphyses strongly branched 253 253a Campylidia consisting of a thalloid tube and a short, brownish "ear"; excipulum paraplectenchymatic Sporopodium b Campylidia consisting of a large, greyish "ear" sitting directly on the thallus; excipulum paraplectenchymatic Calopadia 260a Ascocarps compound, with several, often punctiform discs in raised areas concolorous with the thallus or differently colored (stromatoid); spores transversely septate only 261 b Ascocarps simple, with single disc, at age sometimes deformed (not stromatoid); spores transversely septate or muriform 270 261a Thallus felty, greenish Dichosporidium b Thallus with compact upper layer 262 262a Discs arranged in lines, often loosely accumulated 263 b Discs not arranged in lines, densely accumulated in roundish groups 264 263a Discs in whitish fields differing from the thallus; thallus greenish to yellowish; spores 4-celled, c. 15-20 x 5 µm "Leucodecton" seriale b Discs in fields not differing from the thallus: thallus whitish, dull; spores variously septate Enterographa 264a Ascocarp discs wider, pruinose, in rounded groups [Syncesia] b Ascocarp discs punctiform, blackish 265 265a Spores bacillar, 3-8-septate, widest above the middle and gradually tapering towards both ends; no red pigment in medulla Chiodecton b Spores biclavate, 4-7-septate, with a larger and a smaller swollen part; often with spotted red pigment in medulla Erythrodecton 270a Ascocarps without margin, adnate over their whole width; asci broad-clavoid to globose, with thick apical dome with large ocular chamber (Arthonia-type); spores variously septate, often macrocephalic (with one terminal cell much larger than the others) 271 b Ascocarps with distinct, thalloid or lecideine margin; asci elongate, with thin apical dome with small ocular chamber, often surrounded by small I+ blue ring (Opegraphaceae-type); spores transversely septate only, never macrocephalic (terminal cells not larger than the others) 274 271a Hymenium gelatinous, not byssoid; ascocarps clearly distinct 272 b Hymenium byssoid, not gelatinous; ascocarps sometimes scarcely distinct from thallus 273 272a Spores transversely septate only (when discs punctiform and more or less grouped, see Enterographa) Arthonia b Spores muriform Arthothelium 273a Spores transversely septate only Stirtonia b Spores muriform Cryptothecia 274a Apothecial margin carbonized throughout, black 275 b Apothecial margin not carbonized externally, whitish or thalloid 276 275a Ascospores acicular, 3-45-septate; disc permanently black [Bactrospora] b Ascospores fusiform, 3-19-septate; disc often yellow- pruinose Cresponea 276a Apothecia with thalloid margins covering a dark excipulum, not constricted at base Mazosia b Apothecial margin not thalloid, without algae; often constricted at base 277 277a Ascospores 3-septate; apothecia appressed and large, often over 2 mm diam. Sagenidiopsis b Ascospores 5-7-septate; apothecia sessile with constricted base, not over 1.5 mm wide Lecanactis 280a Spore lumina rounded at maturity by abundant endospore 281 b Spore lumina cubical, at most with lightly rounded edges, without or with scarce endospore 290 281a Hymenium separated from the surrounding apothecium margin by a split; in dry state seemingly with a double margin Thelotrema b Hymenium not separated from the margin 282 282a Margin not carbonized, apothecia immersed in the thallus 283 b Margin at least partly carbonized and black; apothecia more or less exserted 284 283a Apothecial margin round; discs tiny, rarely over 0.5 mm wide Myriotrema b Apothecial margin lacerate, forming slips which cover the disc in part; discs often several mm wide "Thelotrema" pr.p. 284a Apothecia with raised thalline margin, discs visible through thallus splits, pale, often white-pruinose Ocellularia b Apothecia exserted above thallus, without thalloid margin; discs brownish 285 285a Apothecia compound, with several, often elongated discs level with the margin; spores hyaline, transversely septate Glyphis b Apothecia simple; margin raised above the disc; spores grey, muriform Gyrostomum c Apothecia simple; margin not exserting the disc, sometimes with thalline fragments; spores grey, bacillar Phaeographis pr.p. 290a Paraphyses branched and anastomosing throughout Gyalideopsis b Paraphyses unbranched, except sometimes near the tips 291 291a Terrestrial; spores grey, muriform Diploschistes b Epiphytic, rarely on rock; spores various 292 292a Apothecia immersed or level with thallus, often over 1 mm large; margin lacerate or not 293 b Apothecia sessile with constricted base, mostly under 1 mm large; margin entire or crenate 294 293a Margin lacerate "Thelotrema" (perhaps better included in Chroodiscus) b Margin entire or inapparent Cyclographina 294a Apothecia proliferating from their margins and thus forming coralloid-branched structures, greenish; on twigs or leaf margins; spores 6-8-celled; hymenium usually absent Polystroma b Apothecia not proliferating, pale yellow to orange; on various substrates; spores bicellular Dimerella c Apothecia not proliferating, with carbonized excipulum more or less covered by pale pruina or thallus; on mosses or decaying bark or wood; spores muriform Ramonia 300a (201) Spores simple 301 b Spores septate 302 301a Spores thickwalled, spherical; paraphyses persistent Monoblastia b Spores thinwalled, elongate; paraphyses disappearing in an early stage [Verrucaria] 302a Spores (finally) brown 303 b Spores persistently colorless 314 303a Spore septa thin 304 b Spore septa seemingly thick, due to thickened endospore 305 304a Spores with 1-3 transverse septa; ascomata simple Mycomicrothelia b Spores muriform; ascomata multilocular by lateral fusion of separate ostioles Mycoporum 305a Spores muriform Anthracothecium b Spores transversely septate only, with 3 or more septa 306 d Spores uniseptate 307 306a Spores three- or more-septate, under 50 µm long when three-septate Pyrenula b Spores three-septate, over 70 µm long Architrypethelium 307a Spores without pigment granules in endospore Distopyrenis b Spores with pigment granules in endospore [Granulopyrenis] 314a Spores septa seemingly thick, due to thick endospore layer, causing rounded lumina; ascomata often compound, in extensive pseudostromata 315 b Spore septa thin; ascomata usually simple 323 315a Spores muriform 316 b Spores transversely septate only 319 316a Ostiole apical 317 b Ostiole lateral, free or fused 318 317a Ascomata in brown, usually shiny pseudostromata containing yellow or orange pigments, K- or K+ red; pseudostroma wall composed of brown, jigsaw puzzle-like hyphae Bathelium b Ascomata not in brown pseudostromata, or wall not composed of brown, jigsaw puzzle-like hyphae Laurera 318a Ostioles free [Campylothelium] b Ostioles fused to other ostioles to form compound ascomata Cryptothelium 319a Thallus poorly developed, indicated by a whitish patch on bark; ascomata naked at maturity, never aggregated in pseudostromata Pseudopyrenula b Thallus well developed; ascomata immersed in thallus or in pseudostromata 320 320a Ostioles free, apical 321 b Ostioles fused to form a compound ascoma Astrothelium 321a Paraphyses branched and anastomosing; ascus apex with narrow ring surrounding a small ocular chamber; wall thickening of spores most pronounced in the edges of the septae Trypethelium b Paraphyses unbranched; ascus apex with a wide apical ring and wide ocular chamber; wall thickening of the spore more equal (incl. Plagiotrema lageniferum) Lithothelium 323a Ascus tip thin and uniform, truncate; ascomal wall often bright colored (Trichotheliaceae); paraphyses unbranched 324 b Ascus tip more or less thickened with an apical indentation, rounded; paraphyses often branched 327 324a Ascomata with a subapical whorl of stiff black hairs Trichothelium b Ascomata without hairs 325 325a Spores transversely septate; asci with chitinoid apical ring (incl. Trichothelium sensu Harris 1995 pr.p., Pseudosagedia) Porina b Spores muriform; asci without chitinoid apical ring, with slight subapical constriction 326 326a Medulla white or pale yellowish Clathroporina b Medulla yellow to orange or brownish Myeloconis 327a Paraphyses mostly unbranched; macroconidia usually present, cylindrical, septate Strigula b Paraphyses branched, especially above level of asci; macroconidia more or less globose or lacking 328 328a Ascomata multilocular, chambers laterally fused with separate ostioles 329 b Ascomata simple 330 329a Spores with 1-3 transverse septa only [Tomasellia] b Spores muriform Mycoporum 330a Spores muriform 331 b Spores transversely septate 335 331a Asci with indistinct apical thickening; spores usually 8/ascus; (following Harris 1995 with inclusion of Aspidothelium, with an apical disc-like expansion or subapical scales on the perithecia) Thelenella b Asci with pronounced apical thickening with strong ocular chamber (Arthopyrenia-like), spores 2/ascus in neotropical species Julella 335a Spores fusiform, 3-11-septate, over 4 µm wide; asci and paraphyses as in Trypethelium Polymeridium b Spores filiform, 5->10-septate, 1.5-2 µm wide Celothelium c Spores ovoid-fusiform, 1-septate, rarely 3-septate in old age 336 336a Lower spore cell usually the shorter; lichenized; microconidia globose to ellipsoid; macroconidia often present, simple, globose to ellipsoidal; ostiole often lateral Anisomeridium b Lower spore cell usually the longer; mostly non- lichenized; microconidia rod-shaped; macroconidia lacking; ostiole always apical 337 337a Paraphyses slender, without refractive bodies near the septa; asci clavate Arthopyrenia b Paraphyses short-celled, with refractive bodies near the septa; asci obpyriform Naetrocymbe 350a (201) Paraphyses branched and anastomosing; hymenium I+ red or blue; spore lumina not rounded, at most with slightly rounded edges; asci with rather thin apical dome with small ocular chamber often surrounded by a small I+ blue ring 351 b Paraphyses unbranched except sometimes near the tip; hymenium I-, rarely pale blue; spore lumina often rounded, more or less lentiform; asci usually with distinct apical dome, completely I-negative 355 351a Ascocarp walls (labiae) conspicuous and carbonized, at least internally 353 b Ascocarp walls indistinct, not carbonized 354 353a Spores with transverse septa only; excipulum externally carbonized; Opegrapha b Spores muriform; excipulum with outer thalline cover; ascocarps often short lirelliform to rounded Helminthocarpon 354a Spores muriform Arthothelium b Spores transversely septate only Arthonia 355a Ascocarps in stellate or rounded clusters 356 b Ascocarps single 360 356a Spores muriform, colorless Medusulina b Spores transversely septate only 357 357a Spores colorless; merocarps with rounded ends Glyphis b Spores grey to brown;merocarps with pointed ends Sarcographa 360a Spores biloculate, with cubical lumina Melaspilea b Spores pluriloculate, mostly with lenticular lumina (when mature) 361 361a Spores transversely septate only, with lenticular lumina (when mature) 362 b Spores muriform 363 362a Spores colorless Graphis b Spores brown Phaeographis 363a Spores colorless, with or without lenticular lumina (when mature) 364 b Spores grey to brown, with lenticular lumina (when mature) Phaeographina 364a Paraphyses unbranched, also at the tips; spore lumina lenticular when mature Graphina b Paraphyses branched and anastomosing in the epithecium only, parallel below; spore lumina persistently cubical Cyclographina 401a (200, sterile, crustose) Thallus leprose, consisting only of soredia 402 b Thallus byssoid, of woolly appearance while without cortex and entirely composed of very loose hyphae 403 c Thallus not leprose or byssoid. Here many usually sorediate or isidiate species would key out, belonging to various groups like Pertusaria, Thelotremataceae, Porina. Only a selection is included here 406 402a Thallus bright yellow, fine-grained Chrysothrix b Thallus shades of grey Lepraria 403a Thallus zoned, i.e. with a differentiated marginal zone, of a paler color and gradually thinning out 404 b Thallus not zoned, usually with an abrupt border, often lobed Crocynia 404a Thallus margin whitish; thallus greenish, with felty isidia Dichosporidium b Thallus margin blackish; thallus pinkish, without isidia Sagenidiopsis c Thallus margin whitish; thallus bluegreen, without isidia Dictyonema 406a Medulla with conspicuous color, yellow, orange or reddish 407 b Medulla white 415 407a Medulla completely or partly red or pink; sorediate or isidiate 408 b Medulla orange or yellow; sorediate 409 408a Medulla with scattered red spots; thallus surrounded by black prothallus and with soralia Erythrodecton b Medulla pink throughout; with glossy, short, clavate isidia; with hypoprotocetraric acid Ocellularia rhodostroma 409a Thallus greenish, glossy, with scattered soralia-like, yellow spots Myeloconis b Thallus grey, dull, with raised, often dense, yellow soralia Megalospora "chlorites" 415a With soralia 416 b With schizidia; forest undergrowth species 420 c With isidia 425 416a Thallus C+ red; on well-lit sites Pertusaria velata b Thallus C-; on tree trunks in forest 417 417a Soredia fine; with stictic acid (P+ orange, K+ orange) "Thallotrema" b Soredia coarse, in part corticate; with hypoprotocetraric acid (P-, K-) Myriotrema neofrondosum 420a Schizidia accumulated in groups, which may look soralium-like and may be raised or shortly stalked; with hypoprotocetraric acid (P-, K-) Myriotrema neofrondosum b Schizidia arising single, leaving scattered scars on the thallus 421 421a Thallus bluegrey-pruinose; with unknown substance Myriotrema sp. b Thallus greenish, not pruinose; with various substances 422 422a Schizidia small, less than 0.2 mm wide; with protocetraric acid (P+ red) Myriotrema parvidiscum b Schizidia 0.5-0.6 mm wide 423 423a With psoromic acid (P+ yellow, K-) Ocellularia berkeleyana b With stictic acid (P+ orange, K+ orange) Myriotrema sp.? c With cinchonarum unknowns (P+ red) Myriotrema sp.? 425a Forest undergrowth species with large, greenish, glossy thalli 426 b Various habitats, thallus different not treated 426a Isidia cylindrical; with psoromic acid (P+ yellow) Myriotrema hartii b Isidia flagellate, gradually tapering from the base to the tip, with basal constriction and easily falling off; no lichen substances (P-) Thelotrema brasiliensis 450a (200) Conidangia campylidia, with "ear"-shaped, grey or brownish, geotropically directed extension (see also couplet 181 f.f.) "Pyrenotrichum", 451 b Conidangia hyphophores, brush-like with widened tip carrying a gelatinous "drop"; usually immixed with longer, sterile hairs Echinoplaca c Conidangia immersed not treated 451a Campylidia producing simple, pyriform or short- bacillar conidia 452 b Campylidia producing septate, filiform conidia 453 452a "Ear"-shaped part short, on top of a short, thalloid cylinder Sporopodium b "Ear"-shaped part large, directly on thallus Musaespora 453a Campylidia grey, producing conidia without appendages Calopadia b Campylidia brown, producing conidia with appendages Badimia
by Harrie Sipman, for the Biological Diversity of the Guiana Shield Program, 1997
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