Analysis of surface structures of Cladonia mitis podetia in historic and recent collections from Greenland
Field observations in Greenland combined with a scanning electron microscopical survey have revealed a hitherto undescribed correspondence in the distribution of a brownish colour and a crust-like surface structure formed by hyphae at exposed parts of the shoot tips of podetia of Cladonia mitis. A d...
Published in: | Canadian Journal of Botany |
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Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Canadian Science Publishing
1995
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Subjects: | |
Online Access: | http://dx.doi.org/10.1139/b95-046 http://www.nrcresearchpress.com/doi/pdf/10.1139/b95-046 |
Summary: | Field observations in Greenland combined with a scanning electron microscopical survey have revealed a hitherto undescribed correspondence in the distribution of a brownish colour and a crust-like surface structure formed by hyphae at exposed parts of the shoot tips of podetia of Cladonia mitis. A different brownish colour pattern is caused by fungal parasites. A comparable but less prominent colour-crust syndrome was observed on C. mitis from Denmark. The colour-crust syndrome is considered an unhealthy and damaged condition, and the light microscope reveals that areas with this syndrome mainly consist of the uncovered stereome devoid of the hyphal zone containing algal colonies. In a comparative study of podetia collected up to 105 years ago in Greenland, crust-like surface structures occur more frequently since the 1970s. Key words: Arctic lichen heath, Cladonia mitis, Greenland, podetial morphology, UV-B radiation. |
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