The ultrastructure of the symbionts ofRhizocarpon geographicum, Parmelia conspersa andUmbilicaria pustulata growing under dryness conditions

AbstractThe weathering phenomena resulting from the growth of six foliose and crustose lichens (Parmelia subrudecta, Xanthoria ectaneoides, Parmelia conspersa, Aspicilia radiosa, Caloplaca sp. and Ochrolechia parella) on three mafic rocks have been studied. The bioweathering results in more or less extensive fragmentation and corrosion of the mineral surfaces immediately beneath the lichen thalli and in the formation, in the thallus or at the rock-lichen interface, of secondary products. The significant amounts of whewellite found in all interfaces, and the bipiramids of weddellite detected at the serpentine rock-Ochrolechia parella interface, suggest that the oxalic acid secreted by the mycobiont is the chemical substance principally involved. The capacity of the lichens to alter their rock substrata does not appear to be related to their thallus morphology.

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Determination of chemical composition and antimicrobial, antioxidant and cytotoxic activities of lichens Parmelia conspersa and Parmelia perlata

Journal of Food Measurement & Characterization ◽

10.1007/s11694-020-00672-1 ◽

2020 ◽

Author(s):

Nedeljko T. Manojlović ◽

Aleksandar B. Rančić ◽

Rachel Décor ◽

Perica Vasiljević ◽

Jovica Tomović

Keyword(s):

Chemical Composition ◽

Cytotoxic Activities ◽

Parmelia Conspersa

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Les Apothecies et les Asques du Parmelia conspersa (Discolichen Parmeliacee)

The Bryologist ◽

10.2307/3241586 ◽

1970 ◽

Vol 73 (1) ◽

pp. 39 ◽

Cited By ~ 8

Author(s):

Marie-Agnes Letrouit-Galinou

Keyword(s):

Parmelia Conspersa

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Chemistry of Australian Lichens. I. Some Constituents of Parmelia conspersa (Ehrh.) Ach., Ramalina fraxinea (L.) Ach., Usnea barbata (L.) Wigg., and U. ceratina Ach., from the New England Region

Australian Journal of Chemistry ◽

10.1071/ch9600277 ◽

1960 ◽

Vol 13 (2) ◽

pp. 277 ◽

Cited By ~ 8

Author(s):

GP Briner ◽

GE Gream ◽

NV Riggs

Keyword(s):

New England ◽

Usnic Acid ◽

Water Soluble ◽

The World ◽

Parmelia Conspersa ◽

Soluble Fractions

Each of the species named in the title has yielded (+)-usnic acid, as found in previous investigations in other parts of the world. Other aromatic constituents isolated, except salazinic acid from Parmelia conspersa differ from those previously reported and include a new compound from P. conspersa. It is suggested that usnaric acid, previously obtained from Usnea spp. but unidentified, was a mixture of salazinic and norstictic acids. D-Mannitol or D-arabitol has been isolated from the water-soluble fractions.

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