Pseudocyphellaria is a genus of large, leafy lichens that are sometimes referred to as "specklebelly" lichens.[1] The genus has a widespread distribution, especially in south temperate regions, and contains about 170 species.[2] They resemble Lobaria, except that most species of Pseudocyphellaria have conspicuous pseudocyphellae on their lower surface, a characteristic that was once considered unique to this genus.[1] Some species contain pulvinic acid-related pigments; in these species the soredia and pseudocyphellae can be bright yellow.[1]
Some species of Pseudocyphellaria appear to be able to use either a cyanobacterium or a green algae as their photobiont. DNA tests have shown that the fungal symbionts in P. murrayi (which is in a symbiosis with a cyanobacterium) and P. rufovirescens (which is in a symbiosis with a green alga) are actually the same species.[6] This means that P. murrayi-P. rufovirescens is actually one species of fungus that is capable of forming two very different lichens, one with a cyanobacterium and one with a green alga.[6] Two other possible pairs of Pseudocyphellaria species that may be capable of choosing their photobiont are P. knightii-P. lividofusca, and P. kookeri-P. durietzii.[6]
Most Pseudocyphellaria grow on trees in coastal areas, from the subtropics to the boreal zones, although some species can occasionally be found growing on mossy rocks or growing inland.[1] Many species of Pseudocyphellaria are restricted to old-growth forests in humid areas, and are therefore threatened by logging.[1] The limited light conditions of dense young forests can severely decrease the growth of Pseudocyphellaria crocata compared to more open, old-growth forests, and the excess of light from clearcuts can also cause damage to the lichen.[7] Because they are often restricted to humid forests in undisturbed areas, species of Pseudocyphellaria are often used as indicators of valuable old growth forests.[1]
Pseudocyphellaria rainierensis is listed as vulnerable in Canada by COSEWIC. Pseudocyphellaria crocata has disappeared from much of Scandinavia,[8] a development that has been partly attributed to an increase in grazing from snails, presumably as a result of global warming.[9] In the areas of Scandinavia where P. crocata is still found, it seems restricted to growing on smaller twigs that are harder for the snails to reach.[9]
Several species of Pseudocyphellaria can be utilized to produce a brown to orange-brown dye,[11] and some of them have been used to dye wool in Britain and Scandinavia.[12] One species of Pseudocyphellaria is used in Madagascar to make a tea used to treat indigestion.[13]
Besides being yellow, pulvinic acid derivatives are highly toxic.[14] Any species of Pseudocyphellaria that has yellow structures probably contains one of these compounds,[1][15] and may be toxic if ingested.
^ abcdefghBrodo, I. M., S. D. Sharnoff, and S. Sharnoff. 2001. Lichens of North America. Yale University Press: New Haven. ISBN0-300-08249-5
^Kirk PM, Cannon PF, Minter DW, Stalpers JA (2008). Dictionary of the Fungi (10th ed.). Wallingford: CABI. p. 568. ISBN978-0-85199-826-8.
^Vainio, E.A. (1890). Étude sur la classification naturelle et la morphologie des Lichens du Brésil. Pars prima. Acta Societatis pro Fauna et Flora Fennica (in Latin). Vol. 7. p. 182.
^ abcArmaleo, D; Clerc, P (1991). "Lichen chimeras: DNA analysis suggests that one fungus forms two morphotypes". Experimental Mycology. 15: 1–10. doi:10.1016/0147-5975(91)90002-U.
^Gauslaa Y; K Palmqvist; KA Solhaug; H Holien; O Hilmo; L Nybakken; LC Myhre & M Ohlson (2007). "Growth of epiphytic old forest lichens across climatic and successional gradients". Canadian Journal of Forest Research. 37 (10): 1832–1845. doi:10.1139/X07-048.
^Tønsberg T., Gauslaa Y., Haugan R., Holien H., Timdal E. 1996. The threatened macrolichens of Norway – 1995. Sommerfeltia, 23: 1–283.
^ abGauslaa, Y. (2008). "Mollusc grazing may constrain the ecological niche of the old forest lichen Pseudocyphellaria crocata". Plant Biology. 10 (6): 711–7. doi:10.1111/j.1438-8677.2008.00074.x. PMID18950428.
^Emmerich, Robert; Giez, Ingrid; Lange, Otto L.; Proksch, Peter (1993). "Toxicity and antifeedant activity of lichen compounds against the polyphagous herbivorous insect Spodoptera littoralis". Phytochemistry. 33 (6): 1389. Bibcode:1993PChem..33.1389E. doi:10.1016/0031-9422(93)85097-B.
^Garbarino, J. A., W. Quilhot, M. Piovano, and C. Rubio. 1991. Studies on Chilean lichens. XVIII. Additions to the chemistry of Pseudocyphellaria. Boletin De La Sociedad Chilena De Quimica 36(4): 229-231.
