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Type specimens of the Rhizocarpon geographicum group. Thallus habits are shown in the left hand panels (i) and ascospores are shown in the right hand panels (ii). Ai & ii, R. drepanodes (M-0024019); Bi & ii, R. ferax (UPS L-108361); Ci & ii, R. tinei subsp. arcticum (UPS L-582559); Di & ii, R. diabasicum (H-9502464); Ei & ii, R. frigidum (S L-587); Fi & ii, R. prospectans (H-9502588); Gi & ii, R. lecanorinum (L-0399782); Hi & ii, R. macrosporum (UPS L-069173); Ii & ii, R. lindsayanum (H-9502545); Ji & ii, R. riparium (H-9502857); Ki & ii, R. saanaënse (H-9502520); Li & ii, R. sphaerosporum (S L-571); Mi & ii, R. sublucidum (H-9502642); Ni & ii, R. tavaresii (H-9502640). Scales: i = 1mm; ii = 10 µm.
Source publication
As part of a comprehensive revision of the
Rhizocarpon geographicum
species group using molecular and morphological approaches, we examined the name-bearing types of 15 species. We report ambiguities and inconsistencies with the reported features of some type specimens, original descriptions, and circumscriptions employed in keys for the identifica...
Contexts in source publication
Context 1
... Fig. 1Ai & ii) Rhizocarpon ferax H. Magn. ( Fig. 1Ci & ( Fig. 2) As there is no material eligible as a possible lectotype for Linnaeus's name in his herbarium (LINN), and Linnaeus (1753) cited the illus- tration of Dillenius (1742), the illustration serves as original material and has to be designated as a lectotype under Art. 9.12 of the current ...
Context 2
... Fig. 1Ai & ii) Rhizocarpon ferax H. Magn. ( Fig. 1Ci & ( Fig. 2) As there is no material eligible as a possible lectotype for Linnaeus's name in his herbarium (LINN), and Linnaeus (1753) cited the illus- tration of Dillenius (1742), the illustration serves as original material and has to be designated as a lectotype under Art. 9.12 of the current Code ( McNeill et al. 2012). Jørgensen et ...
Context 3
... Leicester Lit. Phil. Soc. 63: 58 (1969 ( Fig. 1Gi & ii) The nomenclature of this taxon is confus- ing because of the use of several very similar epithets: lecanora, lecanoricum, lecanorinum, and lecanorum. Flörke (1819: 4) described his variety "lecanora" from sandstone rocks around "Quedlingburg nach Westerhausen bei Blankenburg"; there can be little doubt that material distributed in the ...
Context 4
... Fig. 1Hi & ii) Rhizocarpon riparium ssp. lindsayanum (Räsänen) Thomson Nova Hedwigia 14: 456 (1967). Basionym: Rhizocarpon lindsayanum Räsänen, Revista Sudamer. Bot. 7: 87 (1942); type: Great Britain, Perthshire, Dunkeld, Birnam Hill, April 1856, W. L. Lindsay (H-9502545-as "Lecidea ...
Context 7
... Fig. 1Ki & ii) Rhizocarpon sphaerosporum Räsänen Ann. Bot. Soc. Zool.-Bot. Fenn. "Vanamo" 19 (not.): 6 (1944); type: Sweden, Uppsala, Gottsunda, 1893, E. Pärsson (S L-571-isotype, as "Rhizocarpon lecanorinum var. cyclica, Rhizocarpon ...
Context 8
... Fig. 1Li & ii) Rhizocarpon sublucidum Räsänen Ann. Bot. Soc. Zool.-Bot. Fenn. "Vanamo" 21 (not. 16): 3 (1947); type: Switzerland, Les Mosses, 1882, E. A. Vainio ...
Context 9
... Fig. 1Mi & ii) Rhizocarpon tavaresii Räsänen Arch. Bot. Soc. Zool.-Bot. Fenn. "Vanamo" 3: 85 (1949); type: Portugal, Minho, Serra do Gerez-Outeiro Moço, 19 June 1947, C. N. Tavares (H-9502641- ...
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Revisions of British and Irish Lichens vol 41: 1–30
Free download available at:
https://britishlichensociety.org.uk/identification/lgbi3
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Lichenometric dating: Science or pseudo-science?—Response to comments by Michael A. O’Neal, pp. 244—245 - Volume 86 Issue 2 - Gerald Osborn, Daniel McCarthy, Aline Walintschek, Randall Burke
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Flood frequency analyses relay on different source of data, including botanical records. Among these, the potential of dendrogeomorphology for flash flood reconstruction in torrential river systems has already been demonstrated in the specialized literature; however, studies combining other approximation techniques such as lichenometry are comparatively less abundant; and very few studies have questioned the advantages and disadvantages of applying these techniques in these particular fluvial environments. Here, we discuss the advantages and limitations of the use of Dendrogeomorphology and Lichenometry in the analysis of flash floods. We provide examples of application in different river systems that show how to overcome the disadvantages and provide complementary and even alternative information to classical sources. The methodological basis of the botanical data sources is based on the periodic environmental changes that condition the growth rate of living trees, manifested in sequence of tree-rings (i.e. studied by Dendrochronology) as well as the growth of several crustaceous lichens’ species, manifested in the accumulated centripetal growth of the stems (studied by Lichenometry). These growth sequences can be used for relative and absolute dating of flood events by identifying growth disturbances related to this process. The results obtained are event dating and measurements of palaeo-stage, flooded area, residence time, depths, velocities and generating flows that can be used for the study of flash floods, allowing to improve the analysis of frequencies and the magnitudes of past floods. Yet, several challenges remain when using these approaches. The interannual variations of these environmental changes (sequences of dry or wet, cold or warm years, variations in insolation, plagues and epidemics, anthropic interference...) could limit the use of these sources for analysing flash floods, given that they require prior filtering processes of the climatic and environmental signal for the identification of disturbances, through the establishment of reference or pattern series, or the development of lichenometric growth curves. However, the advantages and contributions of these data sources and techniques far outweigh the methodological limitations, making them a promising field for the study of environmental changes in river systems.