Þingvellir | |
17 & 21 July 2014 |
Iceland is situated on top of the Mid-Atlantic ridge, which becomes very tangible in the Þingvellir National park. The spreading of the North American and the European plate becomes higly visible in a series of cracks or faults, the largest one, Almannagjá, being an impressive canyon. For this reason, the park is one of the must-sees of Iceland. However, most tourists will be oblivious to a somewhat less obvious richness, that of lichens - unknown, unloved. For everyone who does recognize lichens and appreciates them, this is another reason to visit the park! |
Touching America and Europe within a minute is a very special thing to do! |
Vespula rufa | |
Pertusaria corallina | ||
The black speckles are a parasite on the lichen. |
Dibaeis baeomyces | |
Solorina bispora | |
Stereocaulon spec. & Thamnolia vermicularis |
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Stereocaulon spec. | |
Stereocaulon tomentosum | |
Cladonia spec. | ||
Arthrorhaphis alpina |
Cetraria aculeata & C. islandica | ||
Psoroma hypnorum | |
Peltigera spec. |
Peltigera leucophlebia | ||
Most Peltigera's - like the brownish one above - are symbioses between a fungus and a cyanobaterium. This green Peltigera cf. leucophlebia is a so-called tripartite symbiosis: it consists of a fungus, a green algal symbiont and a cyanobaterial symbiont. The caynobacterial symbiont is housed in the so-called cephalodia, the dark 'warts' sprinkled over the thallus. The cyanobacteria can fix atmospherix nitrogen, definitely an asset in the nutrient-poor soils these lichens grow on. |
Ochrolechia lapuensis & O. frigida | |
Placopsis cf. gelida | |
Another example of a tri-partite symbiosis. The cyanobacteria are housed in the brown cephalodia. |