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Hieracium sect. Oreadea (Asteraceae) in Sweden - from a complete mess to a preliminary taxonomic classification

Tyler, Torbjörn LU (2011) In Nordic Journal of Botany 29(5). p.538-589
Abstract
Among Swedish Hieracium sect. Oreadea (Fr.) Arv.-Touv., more than 100 taxa have been recognized by various experts but, except for a regional monograph from 1894 there are no thorough published revisions of the group and many of the names have never been validly published. At the same time, some of the oldest names have been variously applied to morphologically clearly different species. In the present study, 5000 specimens in Swedish herbaria have been revised using both traditional and statistical morphometric methods and the complicated nomenclature has been disentangled. Twenty-eight species are recognized and described with diagnostic keys and illustrations aiding identification and their known distributions are mapped. Six species... (More)
Among Swedish Hieracium sect. Oreadea (Fr.) Arv.-Touv., more than 100 taxa have been recognized by various experts but, except for a regional monograph from 1894 there are no thorough published revisions of the group and many of the names have never been validly published. At the same time, some of the oldest names have been variously applied to morphologically clearly different species. In the present study, 5000 specimens in Swedish herbaria have been revised using both traditional and statistical morphometric methods and the complicated nomenclature has been disentangled. Twenty-eight species are recognized and described with diagnostic keys and illustrations aiding identification and their known distributions are mapped. Six species are described as new to science (viz. H. marinum T. Tyler, H. eulasium Dahlst. ex T. Tyler, H. victoriae T. Tyler, H. falcifolium Johanss. ex T. Tyler, H. guldbergense Folin ex T. Tyler and H. hispidosum Dahlst. ex T. Tyler) and 3 additional names are raised to the specific rank (viz. H. gigantocybe (Dahlst.) T. Tyler, H. hilare (Dahlst. ex Omang) T. Tyler and H. tanyphyllum (Dahlst. ex Zahn) T. Tyler). Lectotypes are designated for 50 names based on material from Sweden, Norway or Finland and one name is neotypified. Except for a few infraspecific names for which all original material appears to be lost, all names based on material from Sweden are typified. However, it is concluded that albeit the number of taxa is relatively low, the species of H. sect. Oreadea are morphologically less distinct and clear-cut than those of other widespread Scandinavian sections of the genus. Many of the characters that are most important in other sections of the genus are either invariable or unreliable in H. sect. Oreadea. Thus, the taxonomy has to rely on characters more subjected to environmentally-induced modification. Furthermore, members of this section exhibit great morphological plasticity, possibly connected to their preference for exposed rocky habitats where the environmental conditions may be both severe and unpredictable. In addition, due to their ecological demands, they are confined to habitats that have always been both strongly fragmented and restricted in size giving rise to multiple small and locally adapted local populations. The section is here circumscribed in agreement with previous Scandinavian authors, i.e. including both the H. schmidtii-group sometimes referred to H. sect. Stelligera and the H. norvegicum group approaching H. sect. Tridentata, but it is concluded that the section is relatively heterogeneous and that further studies aiming at the identification of more natural supraspecific taxa are much needed. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Nordic Journal of Botany
volume
29
issue
5
pages
538 - 589
publisher
Board of the Nordic Journal of Botany
external identifiers
  • wos:000296490300004
  • scopus:80053651673
ISSN
0107-055X
DOI
10.1111/j.1756-1051.2011.01158.x
language
English
LU publication?
yes
id
d3a4512a-31f1-4d6d-9b2b-44836963784d (old id 2254153)
date added to LUP
2011-12-20 12:14:04
date last changed
2017-11-05 03:14:03
@article{d3a4512a-31f1-4d6d-9b2b-44836963784d,
  abstract     = {Among Swedish Hieracium sect. Oreadea (Fr.) Arv.-Touv., more than 100 taxa have been recognized by various experts but, except for a regional monograph from 1894 there are no thorough published revisions of the group and many of the names have never been validly published. At the same time, some of the oldest names have been variously applied to morphologically clearly different species. In the present study, 5000 specimens in Swedish herbaria have been revised using both traditional and statistical morphometric methods and the complicated nomenclature has been disentangled. Twenty-eight species are recognized and described with diagnostic keys and illustrations aiding identification and their known distributions are mapped. Six species are described as new to science (viz. H. marinum T. Tyler, H. eulasium Dahlst. ex T. Tyler, H. victoriae T. Tyler, H. falcifolium Johanss. ex T. Tyler, H. guldbergense Folin ex T. Tyler and H. hispidosum Dahlst. ex T. Tyler) and 3 additional names are raised to the specific rank (viz. H. gigantocybe (Dahlst.) T. Tyler, H. hilare (Dahlst. ex Omang) T. Tyler and H. tanyphyllum (Dahlst. ex Zahn) T. Tyler). Lectotypes are designated for 50 names based on material from Sweden, Norway or Finland and one name is neotypified. Except for a few infraspecific names for which all original material appears to be lost, all names based on material from Sweden are typified. However, it is concluded that albeit the number of taxa is relatively low, the species of H. sect. Oreadea are morphologically less distinct and clear-cut than those of other widespread Scandinavian sections of the genus. Many of the characters that are most important in other sections of the genus are either invariable or unreliable in H. sect. Oreadea. Thus, the taxonomy has to rely on characters more subjected to environmentally-induced modification. Furthermore, members of this section exhibit great morphological plasticity, possibly connected to their preference for exposed rocky habitats where the environmental conditions may be both severe and unpredictable. In addition, due to their ecological demands, they are confined to habitats that have always been both strongly fragmented and restricted in size giving rise to multiple small and locally adapted local populations. The section is here circumscribed in agreement with previous Scandinavian authors, i.e. including both the H. schmidtii-group sometimes referred to H. sect. Stelligera and the H. norvegicum group approaching H. sect. Tridentata, but it is concluded that the section is relatively heterogeneous and that further studies aiming at the identification of more natural supraspecific taxa are much needed.},
  author       = {Tyler, Torbjörn},
  issn         = {0107-055X},
  language     = {eng},
  number       = {5},
  pages        = {538--589},
  publisher    = {Board of the Nordic Journal of Botany},
  series       = {Nordic Journal of Botany},
  title        = {Hieracium sect. Oreadea (Asteraceae) in Sweden - from a complete mess to a preliminary taxonomic classification},
  url          = {http://dx.doi.org/10.1111/j.1756-1051.2011.01158.x},
  volume       = {29},
  year         = {2011},
}