Flechtenbilder (Ca-Ce)

Caeruleum-heppii-2014Wernicke Caeruleum heppii (Naegeli ex. Körb.) Knudsen & Arcadia (syn. Acarospora heppii).
On a small, rounded stone.
Thallus inconspicuous; apothecia very tiny (0.2-0.4 mm diam.); disc with an yellow greenish pruina. No spot reactions.
Central Europe; Germany: Hesse.
(Coll: Wernicke/id: Eichler/Cezanne).
Calicium-abietinum-7500 Calicium abietinum Pers.
On a dead Quercus tree.
Thallus immersed; apothecia stalked (0.5-1 mm high), not pruinose; mazaedium black; spores with a warty ornamentation; stalk often with a brownish tinge. No spot reactions. Distinctive from other Calicium species by the missing pruina, the warty spores and the occasionally brownish stalk. Central Europe; Germany; Hesse: Vogelsberg. (Collected by M. Heerd).
Calicium-adspersum-6096 Calicium adspersum Pers.
On old Quercus petraea.
Thallus granular, grey; apothecia stalked (0.6-1.5 mm high), with a greenish yellow pruina on the head of the capitulum (on young specimen); mazaedium black. Thallus K+ red, Pd+ yellow to orange. Distinctive from other Calicium species by the yellow pruina and the thallus K+ red reaction. Central Europe; Germany: Hesse.
Calicium-glaucellum-433 Calicium glaucellum Ach.
On a dead birch tree.
Thallus immersed or inconspicuous; apothecia stalked (0.5-1 mm); capitulum 0.2-0.3 mm diam., a thin white pruina along the edge of the exipulum is often existent; mazaedium black. No spot reactions. Distinguishable from other Calicium species by the short stalks an the ring of white pruina. Central Europe; Germany; Rheinland-Pfalz: Hunsrück.
Calicium-salicinum-435 Calicium salicinum Pers.
On a dead birch tree.
Thallus inconspicuous; apothecia stalked (1-2 mm); mazaedium black; underside of the capitulum brown; spores one-septate, brown, with an spirally arranged ornamentum. No spot reactions. Distinctive to other Calicium species is the brown underside of the capitulum, the inconspicuous thallus and the ornamentation of the spores.
Central Europe; Germany: Rheinland-Pfalz.
Calicium-trabinellum-CE2125 Calicium trabinellum (Ach.) Ach.
In bark crevices and on wood. Thallus immersed or inconspicuous; apothecia stalked (0.4-1 mm); mazaedium black; lower side of the capitulum with a yellow pruina. No spot reactions. Distinctive to other Calicium species is the yellow pruina on the underside of the capitulum (C. ad- spersum on the head) and the inconspi- cuous thallus. Central Europe: Germany.
(Coll/ident: Eichler/Cezanne).
Calicium-viride-CE Calicium viride Pers.
On the acid bark of conifers and oak. Thallus consisting of granules or warty; apothecia relatively big, stalked (0.6-2 mm); mazaedium black; lower side of the capitulum with a brown pruina. No spot reactions. Distinctive to other Calicium species is the brown pruina on the underside of the capitulum (C. salicinum is smaller and the thallus is inconspicuous). Central Europe: Germany.
(Coll/ident: Eichler/Cezanne).
Caloplaca-decipiens-8062 Calogaya decipiens (Arnold) Arup, Frödén & Søchting
On calcareous rocks and walls; frequent.
Thallus rosette-forming, up to 3 cm diam.; lobes elongate, convex, with palmate tips, pruinose; soredia at the ends of the inner lobes, concolorous, granular. Thallus K+ red. The soredia of the similar C. cirrochroa are laminal and brighter than the lobes; C. saxicola is not sorediate but with apothecia.
Central Europe; Germany; Bavaria; near Würzburg.
Calogaya-decipiens-141120 Calogaya decipiens (Arnold) Arup, Frödén & Søchting
On a calcareous wall.
Central Europe; Germany: Hesse.
Caloplaca-decipiens-01 Calogaya decipiens (Arnold) Arup, Frödén & Søchting
On a calcareous wall.
Central Europe; Germany: Baden-Württemberg.
Calogaya-pusilla-141120 Calogaya pusilla (A. Massal.) Arup, Frödén & Søchting
On a calcareous wall.
Central Europe; Germany: Hesse.
Caloplaca-arcis-8298 Caloplaca arcis (Poelt & Vezda) Arup
On calacareous rocks.
Thallus squamulose; blastidia/isidia at the margins of areoles (30-130 µm diam.; apothecia rare.
Central Europe; Germany: Hesse (Rhön mountains).
Caloplaca-arenaria Caloplaca arenaria (Pers.) Müll. Arg.
On siliceous rocks.
Thallus not sorediate, inconspicuous or apothecia placed on thalluses of other lichen species; apothecia up to 0.7 mm in diameter, orange to rust-brown or rust-red; margins usually paler than the disc; spores 12-16 x 4-6,5 µm, septum 2-3,5 µm wide.
Austria: Alps.
Caloplaca-arnoldii-Solms-1850 Caloplaca arnoldii (Wedd.) Zahlbr.
On old tiles.
Thallus epruinose, lobate at the margin, crustose in the center; apothecia 0.2-0.5 mm, margin persistent. Thallus K+ red. The similar C. saxicola is densely pruinose. Central Europe; Germany: Hesse. (Coll: Graf zu Solms (1860!)/ident: Eichler!Cezanne).
Calpolaca-aurantia-6646 Caloplaca aurantia (Pers.) Steiner
On calcareous rocks.
Thallus bright yellow at the margins (darker in the centre); lobes distinctly adpressed and flat, palmate at the tips (difference to the similar C. flavescens: lobes convex, narrow, separated from each other, only slightly palmate at the ends); apothecia common, disc orange to brownish with a slightly brighter margin. Thallus and apothecia K+ red.
Central Europe; Germany: Hesse.
Caloplaca-carphinea-6189a Caloplaca scoriophila (Massal.) Steiner syn. Usnochroma s.
On volcanic rocks.
Thallus yellow-green, effigurated; apothecial disc orange-red, flat when young, later convex; margin lecanorine (concolorous with thallus); spores ellipsoid, polarilocular. Thallus KC+ (faintly red); apothecial disc K+ red.
Spain; Canary Islands: La Gomera.
Caloplaca-carphinea-03 Caloplaca scoriophila (Massal.) Steiner syn. Usnochroma s.
On basaltic rocks.
Spain; Canary Islands: La Gomera.
Usnochroma-scoriophila-5605 Caloplaca scoriophila (Massal.) Steiner syn. Usnochroma scoriophila
On basaltic rocks.
Spain; Canary Islands: La Gomera.
Caloplaca-cerina-5196 Caloplaca cerina (Erh. ex Hedw.) Th. Fr.
Corticolous; on the bark of deciduous trees.
Thallus ± areolate, grey; apothecia up to 2 mm diameter; disc yellow- orange, rough; margin thick, lead-grey. Apothecial disc K+ red.
Central Europe: Germany.
Caloplaca-cerinella-7779 Caloplaca cerinella (Nyl.) Flagey
Corticolous.
Similar to Caloplaca cerinellioides, but ascus 12-16-spored.
Central Europe; Germany: Hesse.
Caloplaca-cerinellioides-6082a Caloplaca cerinellioides (Erichsen) Poelt
On twigs of deciduous trees.
Thallus whitish-grey; apothecia small (up to 0.3 mm), clustered; ascus 8-spored (difference to C. cerinella which is 12-16-spored). Apothecia K+ red.
Central Europe; Germany: Hesse.
(Coll/ident: Eichler/Cezanne).
Caloplaca-chlorina-7493a Caloplaca chlorina (Flotow) Oliv.
On eutropicated bark of Acer pseudoplatanus. Also on calcareous and silicatic walls.
Thallus slightly areolate; areoles often covered with granular isidia; apothecia dispersed, up to 1 mm diam., margin thick, irregular. Thallus K+ pale red or K-; apothecial disc K+ red. (The similar C. cerina has crowded apothecia - up to 2 mm - and occurs on bark).
Central Europe; Gemany: Hesse.
Caloplaca-cinnabarina-Namibia-2008 Caloplaca cinnabarina (Ach.) Zahlbr.
On sandstone.
Thallus consisting of distinct, orange areoles. One (or more) apothecia per areole; disc darker orange. Thallus K+ red.
South Africa; Namibia: Waterberg region.
(Identified by V. Wirth).
Caloplaca-cirrochroa-503 Caloplaca cirrochroa (Ach.) Th. Fr.
On calcareous rocks.
Thallus rosette-forming, orange; consisting of prolonged, radiating, convex lobes; ends slightly pruinose; the center of young thalli is areolate, areoles disappearing with age; soralia lemon-yellow, concave. Thallus K+ red.
Austria; Alps: Kärnten.
Caloplaca-citrina-160903 Caloplaca citrina (Hoffm.) Th. Fr.
On mortar of a siliceous wall in a cemetery.
Thallus yellow greenish to bright orange; squamulous to minutely areolate; soralia marginal on young areoles, later often covering the areoles totally; apothecia not very common, disc yellow-orange, margin paler. Thallus K+ red.
Central Europe; Germany; Hesse: Taunusmountains (Espenschied).
Caloplaca-citrina Caloplaca citrina (Hoffm.) Th. Fr.
On mortar walls and calcareous rocks.
Thallus yellow greenish to bright orange; squamulous to minutely areolate; soralia marginal on young areoles, later often covering the areoles totally; apothecia not very common, disc yellow-orange, margin paler. Thallus K+ red.
Central Europe; Germany: Hesse.
Caloplaca-coronata-130602 Caloplaca coronata (Krempelh. ex Körb.) Steiner
On calcareous rocks.
Thallus consisting of areols (up to 1 mm) assoziated with isidia-like granules.
Central Europe; Germany: Hesse.
(Coll/ident: Eichler/Cezanne).
Caloplaca-crenularia-6211 Caloplaca crenularia (With.) Laundon
On basaltic, coastal rocks.
Thallus grey, areolate or absent; apothecia up to 1 mm, disc orange-red to brown-red, rough, margins inconspicuous, paler than the disc, lacking a thalline margin; spores containing two cells, with a broad septum. Apothecia K+ red.
Portugal: Madeira. Spain: Canary islands (La Gomera).
Caloplaca-crenualaria-Solms-1850 Caloplaca crenularia (With.) Laundon
On basaltic rocks.
Central Europe; Germany: Hesse.
(Coll: Graf zu Solms (1860!)/ident: Eichler/Cezanne).
Caloplaca-crenulatella-7147 Caloplaca crenulatella (Nyl.) Olivier
On calcareous rocks.
Thallus unconspicuous, yellowish-grey; apothecia crowded, up to 0.8 mm diam; disc flat; margin persistent, often surrounded by a warty "collar" (see small image). Thallus and apothecia K+ red.
Switzerland: Glarus. (1900 m above sea level).
Caloplaca-dolomiticola-5783 Caloplaca dolomiticola (Hue) Zahlbr.
On calcareous walls.
Thallus yellow, areolated- warted; apothecia numerous, in the center. Thallus K+ red.
Central Europe: Germany; Bavaria; near Würzburg.
Caloplaca-elegantissima-7414 Caloplaca elegantissima (Nyl.) Zahlbr.
On rocks.
Thallus rosette-forming; lobes 0.8-2 x 30 mm, ± convex. Thallus K+ red.
Western Namibia: Near Swakopmund. (Identified by V. Wirth).
Caloplaca-ferruginea-Solms-1850 Caloplaca ferruginea (Huds.) Th. Fr.
On the bark of deciduous trees.
Thallus distinct, grey to whitish, plane to warty; apothecia up to 1.5 mm, disk rusty red to rusty brown, margin persistent. Thallus K+ red, apothecia C+ purple.
(Coll: Graf zu Solms (1860)/ident: Eichler/Cezanne).
Caloplaca-flavescens Caloplaca flavescens (Hudson) Laundon
On vertical calcareous rocks; frequent.
Thallus rosette-forming, often with a whitish zone behind the apices; lobes elongate, convex (the similar C. aurantia has flattened lobe ends), wider at the apices, usually not pruinose; center of the thallus ± areolate, with numerous apothecia (but it often falls ± out); apothecia up to 1.5 mm diam., orange, with paler margins. Thallus K+ red.
Central Europe; Germany: Bad.-Württemb.
Caloplaca-flavocitrina-7789 Caloplaca flavocitrina (Nyl.) Olivier
On base rich bark of deciduous trees;(also on limestone, mortar, asbestos).
Similar to C. citrina, but the bright yellow soredia, the flat areoles and the often corticulous habitat are distinctive.
Central Europe: Germany.
Caloplaca-flavorubescens-6880a Caloplaca flavorubescens (Huds.) Laund.
Corticolous; on the bark of deciduous trees.
Thallus greenish-orange whith lighter areas; often with a greyish prothallus (upper photo, thallus wet); apothecia up to 1 mm diam.; disc convex, dark orange (darker than the thallus); margin paler orange. Thallus and apothecia K+ red. Very similar to C. flavovirescens but on trees.
Austria: Alps.
Caloplaca-flavorubescens-7332 Caloplaca flavorubescens  (Huds.) Laund.
On Juniperus spec.
Spain; Canary Islands: La Gomera.
Caloplaca-flavovirescens-080315a Caloplaca flavovirescens (Wulfen) DT. & Sarnt.
On acid rocks.
Thallus areolate, yellow-orange; apothecia up to 1 mm diam.; disc convex, dark orange (darker than the thallus); margin yellow orange (like the colour of the thallus). Thallus and apothecia K+ red.
Austria: Alps.
Caloplaca-grimmiae-2817a Caloplaca grimmiae (Nyl.) Oliv.
On silicatic rocks (e.g. Basalt), living parasitic on Candelariella vitellina (also on C. coralliza).
Without visible thallus; apothecia flat , 1 (1.3) mm in diameter, disc cinnabar coloured, brownish red to dark red, rim lecanorine.
Central Europe; Germany; Hesse.
(Collected/identified by Teuber).
Caloplaca-haematites-s.lat.-3075 Caloplaca haematites (Chaub. ex ST.-Amans) Zwackh.
On twigs of an apple tree.
Thallus granular to areolate; apothecia up to 1 mm, rounded to angular; disc concave to flat, red-brown; rim grey but inner margin orange. Thallus K-, apothecial disk K+ red. Portugal: Madeira.
(Identified by J. Vondrak).
Caloplaca-herbidella-72564 Caloplaca herbidella (Hue) H. Magn.
Corticolous; on bark of deciduous trees.
Thallus thin and continuous, with numerous isidia covering the whole thallus, simple, warted, to coralloid; apothecia up to 1 mm in diameter, rounded to flexuose, margin conspicuous, often twisted. Thallus and isidia K-, C- Pd-; apothecia K+ red. Sterile specimen may be confused with Pertusaria coronata.
Austria, Alps: Tirol.
Caloplaca-irrubescens-248 Caloplaca irrubescens (Arnold) Zahlbr.
On coastal basaltic rocks.
Thallus of small areoles (to 0.5 mm in diameter); apothecia numerous, rounded, up to 0.4 mm in diameter; margins disappearing with age; spores broadly ellipsoid, 8-15 x 4-7 µm. Thallus K+ red.
Portugal: Madeira.
Caloplaca-lactea-Henze Caloplaca lactea (Massal.) Zahlbr.
On calcareous rocks.
Thallus immersed or inconspicuous, white; apothecial disc ± flat, orange; margin paler, often disappearing when mature; spores with one septum, septum very thin. Apothecia K+ red. (The apothecial disc of the similar C. holocarpa is more convex).
Central Europe; Germany; Bavaria; near Würzburg.
Caloplaca-lactea-6053b Caloplaca lactea (Massal.) Zahlbr.
Caloplaca-obscurella-Ute-702 Caloplaca obscurella (Lahm) Fr.
On bark of nutrient enriched deciduous trees (Malus spec.).
Thallus thin, smooth to weakly areolate; with crater-like soralia. Spot reactions negative.
Central Europe; Germany: Hesse.
Caloplaca-pelodella-7936 Caloplaca pelodella (Nyl.) Hasse
On basaltic rocks.
Spain; Canary Islands: La Gomera.
(Identified by J. Vondrak).
Caloplaca-pyracea-7282-Cezanne Caloplaca pyracea (Ach.) T. Fr.
Corticolous; on bark of deciduous trees; common.
Thallus often inconspicuous, grey; apothecia up to 4 mm diam., disc orange, plane, but becoming convex when the paler and glossy margin becomes excluded. Apothecia K+ red.
Central Europe; Germany: Hesse.
(Coll/ident: Eichler/Cezanne).
Caloplaca-pyracea-030420 Caloplaca pyracea (Ach.) T. Fr.
Corticolous.
Portugal: Madeira.
Caloplaca-ruderum-6636a Caloplaca ruderum (Malbr.) Laundon
On calcareous rocks (Zechstein) and walls.
Thallus consisting of coarse granulose areoles, surface uneven, often pruinose; not really sorediate but with fine granules; apothecia - 1.5 mm, often uneven because of compression by surrounding apothecia; true exciple concolorous with the orange disc; thalline exciple thicker, uneven, of the same colour as the thallus. Thallus and apothecia K+ red. Central Europe; Germany: Hesse.
Caloplaca-saxicola-160903 Caloplaca saxicola (Hoffm.) Nordin
On siliceous wall (with mortar) in a cemetery.
Thallus placodioid (up to 2 cm diam.); lobes palmate, convex, pruinose (see small image); apothecia crowded, obscurating the center of the thallus; disc orange-brown, margin paler. Thallus K+ red. (The similar C. flavescens is not pruinose; Xanthoria elegans has separate lobes - at least in parts).
Central Europe; Germany; Hesse: Taunus mountains (Espenschied).
Caloplaca-saxicola-6263a Caloplaca saxicola (Hoffm.) Nordin
On calcareous rocks.
Thallus placodioid (up to 2 cm diam.); lobes palmate, convex, pruinose (see small image); apothecia crowded, obscurating the center of the thallus; disc orange-brown, margin paler. Thallus K+ red. (The similar C. flavescens is not pruinose; Xanthoria elegans has separate lobes - at least in parts).
Central Europe; Germany; Hesse.
Caloplaca-saxicola-150311 Caloplaca saxicola (Hoffm.) Nordin
Caloplaca-stiilicidiorum-Teu2266 Caloplaca stillidicidiorum (Vahl) Lynge
Over mosses and plant debris, preferring carbonate environments.
Thallus whitish to greyish; apothecia lecanorine, disc from yellow over orange, red-brown to dirty olive. Spot reactions negative.
Central Europe; Germany: Hesse.
(Coll/ident. by D. Teuber).
Caloplaca-subpallida-6798a Caloplaca subpallida Magn.
On nutrient enriched rocks.
Thallus grey, cracked-areolate; apothecial disc bright-orange to brownish-orange, up to 0.5 mm diam.; margin concolorous, persistent. Thallus K-; apothecia K+ red.
Central Europe; Germany: Hesse. (150 m above sea level).
(Coll/ident: Eichler/Cezanne).
Caloplaca-subpallida-6798i Caloplaca subpallida Magn.
Caloplaca-teicholyta Caloplaca teicholyta (Ach.) Steiner
On concrete walls.
Thallus slightly placodioid, sorediate in the centre; apothecia rare. Cortex K-; apothecial disc K+ red.
Central Europe; Gemany: Hesse.
Caloplaca-variabilis-6628b Caloplaca variabilis (Pers.) Müll. Arg.
On calcareous rocks.
Thallus brownish, areolate, marginal area whitish; apothecia common, ± sessil, up to 1.2 mm diam.; disc black, with a whithish pruina, margin grey, persistent; spores 17,5 x 10 µm. No spot reactions. This non-orange Caloplaca resembles to Rinodina but the spores are polarilocular.
Central Europe; Germany: Baden-Württemberg.
Candelaria-concolor-7714a Candelaria concolor (Dickson) Stein
Corticolous; on bark of deciduous trees. Not very common.
Thallus consisting of erect minute lobes with incised and sorediate ends; lower side whitish, with pale rhizines (see lower image). No spot reactions.
Resembles to Xanthoria candelaria. Distinct by the more greenish-yellow to lemon-yellow colour and the negative K-reaction.
Central Europe; Germany: Hesse.
Candelaria-pacifica-8226a Candelaria pacifica Westb. & Arup
Corticolous; on the bark of deciduous trees.
Similar to Candelaria concolor but the lower side is arachnoid (no cortex) and the lobes are shorter; rhizines rare; rarely fertile in Europe. No spot reactions.
Central Europe; Germany: Hesse.
(Coll/ident: Eichler/Cezanne).
Candelariella-aurella-7770 Candelariella aurella (Hoffm.) Zahlbr.
On volcanic rocks (Diabas), but also an eutrophicated, dusty bark of deciduous trees.
Thallus consisting of scattered, greenish-yellow squamules, often disappearing; apothecia 0.5-1.2 mm diam.; margin concolorous. No spot reactions.
Central Europe; Germany: Hesse.
Candelariella-coralliza-01 Candelariella coralliza (Nyl.) H. Magn.
On eutrophicated rocks.
Thallus golden yellow, very thick and deeply areolate. No K-reaction. Resembles to C. vitellina, but mostly steril and with thicker thallus.
Central Europe; Germany: Hesse; not rare.
Candelariella-coralliza-7974a Candelariella coralliza (Nyl.) H. Magn.
Candelariella-medians-070312 Candelariella medians (Nyl.) A. L. Sm.
On man-made calcareous substrata.
Thallus placodioid, often areolate to warty in the center; apothecia not seen. No spot reactions. (Resembles to yellow Caloplaca species - especially to C. decipiens, often found at the same subtratum - but the latter have a K+ red reaction)
Central Europe; Germany: Hesse.
Candelariella-reflexa-110907 Candelariella reflexa (Nyl.) Lettau
Corticolous; on bark of deciduous trees.
Thallus yellow-greenish, existing of small (up to 1 mm) scattered squamules which become sorediate. K-reaction negative. Resembles to X. xanthostigma which has no squamules but rounded granules.
Central Europe; very common.
Candelariella-reflexa Candelariella reflexa (Nyl.) Lettau
Candelariella-reflexa-150605-CE Candelariella reflexa(Nyl.) Lettau
Candelariella-vitellina-02 Candelariella vitellina (Hoffm.) Müll. Arg.
Saxicol and corticolous; on nutrient enriched habitats.
Thallus yellow-orange to mustard-yellow, areolate often clumping together (clumps resemble to cauliflower); apothecia common, disc dirty yellow, sometimes darker. K-reaction negative (sometimes reddish). The cracks of the areoles are not as deep as in C. coralliza.
Central Europe; Germany: Hesse.
Candelariella-vitellina-03 Candelariella vitellina (Hoffm.) Müll. Arg.
Candelariella-xanthostigma-8343 Candelariella xanthostigma (Ach.) Lettau
Corticolous; on bark of deciduous trees.
Similar to C. reflexa but consisting of small sorediate granules (up to 0.2 mm; C. reflexa has sorediate squamules up to 1 mm). K-reaction negative.
Central Europe; very common.
Catillaria-atomarioides-1825a Catillaria atomarioides (Müll. Arg.) Kilias
On silicatic (acid) rocks.
Thallus greenish-grey, ± areolate; apothecia very small (up to 0.1-0.2 mm); disc black, flat to convex; margin lecideine. No spot reactions.
Central Europe; Germany: Saar Region.
(Coll/ident: Eichler/Cezanne).
Catillaria-chalybeia-Solms-1850 Catillaria chalybeia (Borrer) Massal.
On silicatic rocks.
Thallus ± areolate, thin to evanescent; apothecia (0.2-0.5 mm), scattered or clustered; disc flat to slightly convex; rim concolorous. Thallus without spot reactions.
Central Europe; Germany: Hesse.
(Coll. by Graf zu Solms, 1860!, ident. by Eichler/Cezanne).
Catillaria-nigroclavata-Teuber Catillaria nigroclavata (Nyl.) Schuler
On young twigs of Fraxinus excelsior.
Thallus thin, dark grey; apothecia always present, up to 0.3 mm diam.; apothecial disc flat; margin distinct, later disappearing; spores one-celled, colourless. No spot reactions.
Resembles to Amandinea punctata but the latter has one-septate brown spores.
Central Europe; Germany: Hesse.
(Collected by Martin Heerd).
Catillaria nigroclavata 9048a  Catillaria nigroclavata (Nyl.) Schuler
On twigs of Carpinus betulus.
Central Europe; Germany: Hesse.
Catillaria nigroclavata 9048b  Catillaria nigroclavata (Nyl.) Schuler
On twigs of Carpinus betulus.
Central Europe; Germany: Hesse.
Catinaria-atropurpurea-6108a Catinaria atropurpurea (Schaerer) Vezda & Poelt
On the bark of Acer pseudoplatanus.
Thallus grey, thin, effusive; apothecia up to 0.7 mm diam.; disc black when dry, dark purple when wet (name), becoming convex with age; margin concolorous, disappearing later. No spot reactions.
Central Europe; Germany: Hesse.
(Coll/ident: Eichler/Cezanne).
Cetraria-aculeata-6400a Cetraria aculeata (Schreb.) Fr.
On acid soil.
Branches up to 4 cm high (up to 1mm diam.); minor branches rounded but older ± flattened, often with white pseudocyphellae near the axils. Spot reactions negative.
The similar C. muricata is smaller (up to 3 cm), the branches are more terete (up to 0.5 mm wide).
Central Europe: Gemany.
Certraria-aculeata-4075a Cetraria aculeata (Schreb.) Fr.
On sandy soil.
Central Europe: Germany.
Certraria-aculeata-4075b Cetraria aculeata (Schreb.) Fr.
On sandy soil.
Central Europe: Germany.
Cetraria-ericetorum-4970a Cetraria ericetorum  Opiz
On poor soils.
Lobes erect, narrow (up to 1 mm), channelled; with marginal, cylindrical projections; pseudocyphellae on the lower side, marginal, +- linear. No spot reactions.
(The pseudocyphellae of the sometimes similar C. islandica are not restricted to the margins and they are elliptical to rounded; medulla Pd+ orange).
Scandinavia; Sweden: Dalarna.
Cetraria-ericetorum-4970bb
Cetraria ericetorum  Opiz
Cetraria-islandica Cetraria islandica (L.) Ach.
On acid, poor soils.
Lobes to 10 mm wide, channelled, moderately branched. Upper surface grey to dark brown, shiny. Marginal pins (0.1-1 mm) frequent. Lower surface often paler, whith conspicuous, laminal white pseudocyphellae (see lowest photo). Medulla Pd+ orange.
Sweden: Värmland, Dalarna.
Cetraria-islandica-6775c Cetraria islandica (L.) Ach.
Cetraria-islandica-01 Cetraria islandica (L.) Ach.
Cetraria-sepincola-1892 Cetraria sepincola (Erh.) Ach.
On twigs of birch-trees.
Thallus forming cushion like tufts. Upper surface grey to olive-brown, ± wrinkled. Apothecia (at the ends of short lobes) covering the whole thallus. Lower surface white to pale brown. No spot reactions.
Sweden: Värmland.
Cetrelia-cetrarioides-8585 Cetrelia cetrarioides (Del. ex Duby) W. & C. Culb.
Corticolous; on deciduous trees in humid habitats; ± rare.
Thallus up to 8 cm; lobes with marginal soralia; upper surface with whitish spot-like pseudocyphellae; lower surface black (brownish towards the margins). Cortex K-, C-, Pd-; medulla C- (difference to C. olivetorum).
Austria: Alps.
Cetrelia-cetrarioides-5468 Cetrelia cetrarioides (Del. ex Duby) W. & C. Culb.
Cetrelia-olivetorum-5090 Cetrelia olivetorum (Nyl.) W. & C. Culb.
Corticolous; on deciduous trees; in humid habitats (Laurisilva); rare.
Thallus up to 8 cm; lobes with marginal soralia; upper surface with whitish spot-like pseudocyphellae; lower surface black (brownish towards the margins). Cortex K-, C-, Pd-; medulla C+ red (difference to C. cetrarioides).
Portugal: Madeira.