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Karis, Per Ola
Publications (10 of 13) Show all publications
Stångberg, F., Karis, P. O. & Anderberg, A. (2018). Intergeneric relationships in the Gorteria clade of Arctotideae-Gorteriinae (Asteraceae), with description of a new genus, Roessleria. South African Journal of Botany, 118, 216-231
Open this publication in new window or tab >>Intergeneric relationships in the Gorteria clade of Arctotideae-Gorteriinae (Asteraceae), with description of a new genus, Roessleria
2018 (English)In: South African Journal of Botany, ISSN 0254-6299, E-ISSN 1727-9321, Vol. 118, p. 216-231Article in journal (Refereed) Published
Abstract [en]

Previous phylogenetic studies in the Arctotideae-Gorteriinae (Asteraceae) have found support for a Gorteria clade. The results also indicated Hirpicium to be paraphyletic, whereas Gorteria and Gazania were found to be monophyletic. Previous investigations at the genus level on this group have focused only on relationships in Gazania and Gorteria, respectively, with only a few Hirpicium species included. In the present study we include more taxa than in any previous investigation, including all species of Hirpicium, all species of Gorteria and almost all taxa of Gazania. Phylogenetic analyses, based on DNA sequence data from non-coding (rps16, trnL-trnF, and psbA-trnH) as well as coding (ndhF) regions from the plastid genome resolved three major clades, but DNA sequence data from the ribosomal regions (ETS and ITS) from the nuclear genome did not support two of the three clades. The genus Hirpicium, as presently circumscribed, was paraphyletic with one group of four species nested within Gorteria and all remaining species of Hirpicium formed a monophyletic group with two clades, morphologically well-defined. As the name Hirpicium is a synonym of Gorteria, new names for the remaining Hirpicium species are proposed. For one of the Hirpicium clades, comprising Hirpicium echinus, we resurrect the genus Berkheyopsis O. Hoffm., and for the five species belonging to the second clade a new generic name, Roessleria Stangb. & Anderb., is proposed. The necessary new combinations, 12 in total, are made, as well as four lectotypifications and one neotypification. A key to the newly circumscribed genera is presented.

Keywords
Africa, Southern Africa, Asteraceae, Gazania, Gorteriinae, Gorteria, Hirpicium, Roessleria, Nomenclature, Systematics, Taxonomy
National Category
Biological Sciences
Identifiers
urn:nbn:se:su:diva-161111 (URN)10.1016/j.sajb.2018.07.018 (DOI)000445521800028 ()
Available from: 2018-10-30 Created: 2018-10-30 Last updated: 2022-03-23Bibliographically approved
Phaliso, N., McKenzie, R. J., Netnou-Nkoana, N. C., Karis, P. O. & Barker, N. P. (2016). Reassessing taxonomic relationships in the Berkheya clade (Asteraceae, Arctotideae-Gorteriinae): the utility of achene morphology. Phytotaxa, 246(1), 1-22
Open this publication in new window or tab >>Reassessing taxonomic relationships in the Berkheya clade (Asteraceae, Arctotideae-Gorteriinae): the utility of achene morphology
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2016 (English)In: Phytotaxa, ISSN 1179-3155, E-ISSN 1179-3163, Vol. 246, no 1, p. 1-22Article in journal (Refereed) Published
Abstract [en]

The genus Berkheya is paraphyletic with the related genera Cullumia, Cuspidia, Didelta and Heterorhachis embedded within a broader clade termed the 'Berkheya clade'. As a contribution towards reassessment of species relationships and delimitation of species groupings within the clade, the utility of external achene morphology for supporting natural species groups within the clade was evaluated. Achenes from 67 species and 10 infraspecific taxa were examined, including representatives of each genus currently recognised in the Berkheya clade. Achene pubescence and pappus characteristics (e.g., scale shape and number of scales within a series) were indicated to be particularly variable and thus less reliable for assessment of species relationships. Of the currently recognised genera, only segregation of Cullumia was supported by achene and pappus characteristics. Species groupings implicit in Roessler's infrageneric classification of eight series within Berkheya were to a large extent supported. However, in particular, series Speciosae was indicated to be a disparate species grouping and the distinction of series Angustae and Cruciatae is not supported by achene and pappus morphology. Achene and pappus characteristics suggest several novel species groupings (e.g. an affinity between Berkheya cuneata, B. ferox and B. spinosa). Although the taxonomic sampling in published molecular phylogenetic analyses is limited, achene and pappus morphology partially supports clades resolved in prevailing phylogenetic reconstructions for the clade. More complete sampling in future molecular phylogenetic analyses is required to test novel species affinities suggested in the present study and to explore the evolution of the achene and pappus in the Berkheya clade.

Keywords
African flora, Compositae, fruit, taxonomy
National Category
Biological Sciences
Identifiers
urn:nbn:se:su:diva-128194 (URN)10.11646/phytotaxa.246.1.1 (DOI)000370199200001 ()
Available from: 2016-03-23 Created: 2016-03-21 Last updated: 2022-02-23Bibliographically approved
Bengtson, A., Nylinder, S., Karis, P. O. & Anderberg, A. A. (2015). Evolution and diversification related to rainfall regimes: diversification patterns in the South African genus Metalasia (Asteraceae-Gnaphalieae). Journal of Biogeography, 42(1), 121-131
Open this publication in new window or tab >>Evolution and diversification related to rainfall regimes: diversification patterns in the South African genus Metalasia (Asteraceae-Gnaphalieae)
2015 (English)In: Journal of Biogeography, ISSN 0305-0270, E-ISSN 1365-2699, Vol. 42, no 1, p. 121-131Article in journal (Refereed) Published
Abstract [en]

AimThe Cape region is known for its exceptional species richness, although much remains unknown regarding the appearance of the modern Cape flora. One explanation is that floral diversification was influenced by the establishment of winter rainfall/summer arid conditions hypothesized to have occurred towards the end of the Miocene. We studied the evolution and diversification of the plant genus Metalasia (Asteraceae-Gnaphalieae), with the aim of testing whether radiation patterns may have been influenced by the climatic changes. LocationSouth Africa, with emphasis on the south-west. MethodsThe radiation of Metalasia was investigated using two approaches: a species diffusion approach, which estimated the ancestral areas by means of a relaxed random walk while sampling from extant distributions; and a discrete approach, in which distributions were defined according to the phytogeographical centres of the Cape region. Secondarily derived clock rates from an earlier Gnaphalieae study were used for calibration purposes. ResultsOur analyses date Metalasia to approximately 6.9Ma, after the Miocene-Pliocene boundary and the establishment of the winter rainfall/summer arid conditions. Metalasia consists of two sister clades: Clade A and Clade B. Clade B, which is endemic to the winter rainfall area, is estimated to have diversified c. 6.4Ma, whereas Clade A, with a main distribution in the all-year rainfall area, is considerably younger, with a crown group age estimated to 3.3Ma. Diversification rates suggest an early rapid speciation, with rates decreasing through time both for Metalasia and for clades A and B separately. Ancestral area estimations show a possible scenario for the radiation of Metalasia to its current diversity and distribution, with no conflict between results inferred from diffusion or discrete methods. Main conclusionsThe diversification of Metalasia is estimated to have begun after the establishment of the winter rainfall/summer arid conditions, consistent with its radiation having been influenced by changes in the climatic regime.

Keywords
Biogeography, Cape flora, Cape Floristic Region, diversity, Metalasia, South Africa, species-tree diffusion, winter rainfall
National Category
Earth and Related Environmental Sciences Biological Sciences
Research subject
Plant Systematics
Identifiers
urn:nbn:se:su:diva-113113 (URN)10.1111/jbi.12390 (DOI)000346069700012 ()
Note

AuthorCount:4;

Available from: 2015-02-23 Created: 2015-01-23 Last updated: 2022-02-23Bibliographically approved
Bengtson, A., Anderberg, A. A. & Karis, P. O. (2014). Phylogeny and evolution of the South African genus Metalasia (Asteraceae-Gnaphalieae) inferred from molecular and morphological data. Botanical journal of the Linnean Society, 174(2), 173-198
Open this publication in new window or tab >>Phylogeny and evolution of the South African genus Metalasia (Asteraceae-Gnaphalieae) inferred from molecular and morphological data
2014 (English)In: Botanical journal of the Linnean Society, ISSN 0024-4074, E-ISSN 1095-8339, Vol. 174, no 2, p. 173-198Article in journal (Refereed) Published
Abstract [en]

Metalasia is a genus in tribe Gnaphalieae (Asteraceae), endemic to South Africa and with its main distribution in the Cape Floristic Region. The genus comprises 57 species and, with a number of closely related genera, it constitutes the Metalasia clade'. A species-level phylogenetic analysis is presented, based on DNA sequences from two nuclear (internal and external transcribed spacer: ITS, ETS) and two plastid (psbA-trnH, trnL-trnF) regions together with morphological data. Analyses combining molecular and morphological data attempt not only to resolve species interrelationships, but also to detect patterns in character evolution. Phylogenetic analyses corroborate our earlier study and demonstrate that Metalasia is formed of two equally sized, well-supported sister groups, one of which is characterized by papillose cypselas. The results differ greatly from earlier hypotheses based on morphology alone, as few morphological characters support the phylogenetic patterns obtained. The two clades of Metalasia do, however, appear to differ in distribution, corresponding to the different rainfall regimes of South Africa. Analyses show a few taxa to be problematic; one example is the widely distributed M.densa which appears to be an intricate species complex.

Keywords
Cape Floristic Region, DNA, morphology, Western Cape
National Category
Botany
Research subject
Plant Systematics
Identifiers
urn:nbn:se:su:diva-100645 (URN)10.1111/boj.12114 (DOI)000329686000002 ()
Note

AuthorCount:3;

Available from: 2014-02-14 Created: 2014-02-10 Last updated: 2022-02-24Bibliographically approved
Bengtson, A., Anderberg, A. A. & Karis, P. O. (2013). Three new species of metalasia (asteraceae gnaphalieae) from the western cape and an updated key to the genus. South African Journal of Botany, 84, 72-82
Open this publication in new window or tab >>Three new species of metalasia (asteraceae gnaphalieae) from the western cape and an updated key to the genus
2013 (English)In: South African Journal of Botany, ISSN 0254-6299, E-ISSN 1727-9321, Vol. 84, p. 72-82Article in journal (Refereed) Published
Abstract [en]

Three new species of Metalasia from the Western Cape of South Africa are described; Metalasia tristis A.Bengtson & P.O.Karis, a small shrublet from the Groot Winterhoek Mountains, and Metalasia formosa A.Bengtson & P.O.Karis and Metalasia eburnea A.Bengtson & P.O.Karis both found in the Langeberg Mountains. The morphology and relationships of the three new species are discussed, and an updated key to the genus is provided.

Keywords
Asteraceae, Gnaphalieae, Metalasia, New species, Taxonomy, South Africa
National Category
Botany
Research subject
Plant Systematics
Identifiers
urn:nbn:se:su:diva-88323 (URN)10.1016/j.sajb.2012.09.008 (DOI)000314261600010 ()
Note

AuthorCount:3;

Available from: 2013-03-19 Created: 2013-03-12 Last updated: 2022-03-23Bibliographically approved
Karis, P. O. & Helme, N. A. (2012). Metalasia namaquana (Asteraceae-Gnaphalieae), a new species from the Kamiesberg (South Africa). South African Journal of Botany, 78, 281-284
Open this publication in new window or tab >>Metalasia namaquana (Asteraceae-Gnaphalieae), a new species from the Kamiesberg (South Africa)
2012 (English)In: South African Journal of Botany, ISSN 0254-6299, E-ISSN 1727-9321, Vol. 78, p. 281-284Article in journal (Refereed) Published
Abstract [en]

The new species Metalasia namaquana is described from the Kamiesberg, a well known centre of plant endemism in the Northern Cape Province of South Africa. The species is most similar to Metalasia fastigiata and Metalasia albescens. The morphology, ecology and conservation status of the new species are discussed.

Keywords
Asteraceae, Granite Fynbos, Kamiesberg, Metalasia R.Br., New species, South Africa, Taxonomy
National Category
Botany
Identifiers
urn:nbn:se:su:diva-76730 (URN)10.1016/j.sajb.2011.06.013 (DOI)000301016800037 ()
Note
2Available from: 2012-05-20 Created: 2012-05-16 Last updated: 2022-03-23Bibliographically approved
Lledó, M. D., Karis, P. O., Crespo, M. B., Fay, M. F. & Chase, M. W. (2011). Endemism and evolution in Macaronesian and Mediterranean Limonium taxa. In: David Bramwell & Juli Caujapé-Castells (Ed.), The biology of island floras (pp. 325-337). Cambridge University Press
Open this publication in new window or tab >>Endemism and evolution in Macaronesian and Mediterranean Limonium taxa
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2011 (English)In: The biology of island floras / [ed] David Bramwell & Juli Caujapé-Castells, Cambridge University Press, 2011, p. 325-337Chapter in book (Other academic)
Abstract [en]

The study of plant speciation on oceanic islands has improved enormously with the help of molecular systematics. Studies have targeted groups present on both the mainland and islands with the aim of understanding plant migration and evolution in isolation. In addition, relatively young volcanic islands give the opportunity to place the evolutionary process in a time frame, by dating molecular trees according to the age of the islands or by relying on the fossil record. Molecular phylogenetics can also be valuable in helping to reconstruct character evolution and understand the syndrome of characters diagnosing oceanic species.

Frontmatter:

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pp. i-ivContents:

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pp. v-viiContributors:

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pp. viii-xiiPreface:

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pp. xiii-xvi1 - Introduction: islands and plants:

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By David Bramwellpp. 1-102 - The reproductive biology of island plants:

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By Daniel J. Crawford, Gregory J. Anderson and Gabriel Bernardellopp. 11-363 - Spatial methodologies in historical biogeography of islands:

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By Paula Posadas, Jorge V. Crisci and Liliana Katinaspp. 37-564 - Origin and evolution of Hawaiian endemics: new patterns revealed by molecular phylogenetic studies:

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By Sterling C. Keeley and Vicki A. Funkpp. 57-885 - Origins and evolution of Galapagos endemic vascular plants:

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By Alan Tye and Javier Francisco-Ortegapp. 89-1536 - The plants of the Caribbean islands: a review of the biogeography, diversity and conservation of a storm-battered biodiversity hotspot:

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By Michael Maunder et al.pp. 154-1787 - The biogeography of Madagascar palms:

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By John Dransfield and Mijoro Rakotoarinivopp. 179-1968 - Evolution and

Place, publisher, year, edition, pages
Cambridge University Press, 2011
Keywords
Mycology, Pharmacology, Plant sciences, Ecology and conservation
National Category
Evolutionary Biology
Identifiers
urn:nbn:se:su:diva-68768 (URN)http://dx.doi.org/10.1017/CBO9780511844270.014 (DOI)978-0-521-11808-8 (ISBN)
Available from: 2012-01-05 Created: 2012-01-05 Last updated: 2022-02-24Bibliographically approved
Bengtson, A., Anderberg, A. A. & Karis, P. O. (2011). PHYLOGENY AND GENERIC DELIMITATION OF THE METALASIA CLADE (ASTERACEAE-GNAPHALIEAE). International journal of plant sciences, 172(8), 1067-1075
Open this publication in new window or tab >>PHYLOGENY AND GENERIC DELIMITATION OF THE METALASIA CLADE (ASTERACEAE-GNAPHALIEAE)
2011 (English)In: International journal of plant sciences, ISSN 1058-5893, E-ISSN 1537-5315, Vol. 172, no 8, p. 1067-1075Article in journal (Refereed) Published
Abstract [en]

The Metalasia clade, which consists of the genus Metalasia and a number of much smaller satellite genera, is a South African group in the tribe Gnaphalieae (Asteraceae). This study scrutinizes the phylogenetic relationships of the Metalasia clade by means of chloroplast (trnL-trnF, psbA-trnH) and nuclear (external transcribed spacer, internal transcribed spacer) sequence data. The Metalasia clade is confirmed to be a monophyletic group, and the phylogenetic positions of the included genera are determined. The genus Metalasia may be monophyletic if the monotypic Planea is included, but the node has very poor support and further studies are needed. The Metalasia species fall into two well-supported groups, distinguishing the members of Karis's Metalasia densa group from the others. Lachnospermum is shown to be monophyletic and is placed as a possible sister group to Metalasia. Phaenocoma is placed as sister to the branch consisting of Metalasia and Lachnospermum. Calotesta, Hydroidea, and Atrichantha form a clade, with the monotypic Dolichothrix as their sister group.

Keywords
Asteraceae, Gnaphalieae, Metalasia, molecular phylogenetics
National Category
Botany
Research subject
Plant Systematics
Identifiers
urn:nbn:se:su:diva-70878 (URN)10.1086/661294 (DOI)000297459200007 ()
Note

authorCount :3

Available from: 2012-01-25 Created: 2012-01-24 Last updated: 2022-02-24Bibliographically approved
Karis, P. O., Funk, V. A., McKenzie, R. J., Barker, N. & Chan, R. (2009). Arctotideae. In: Funk VA, Susanna A, Stuessy TF, Bayer RJ (Ed.), Systematics, Evolution and Biogeography of Compositae: (pp. 285-310). Vienna: International Association for Plant Taxonomy
Open this publication in new window or tab >>Arctotideae
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2009 (English)In: Systematics, Evolution and Biogeography of Compositae / [ed] Funk VA, Susanna A, Stuessy TF, Bayer RJ, Vienna: International Association for Plant Taxonomy , 2009, p. 285-310Chapter in book (Other academic)
Place, publisher, year, edition, pages
Vienna: International Association for Plant Taxonomy, 2009
National Category
Biological Systematics
Research subject
Systematic Botany
Identifiers
urn:nbn:se:su:diva-34739 (URN)978-3-9501754-3-1 (ISBN)
Available from: 2010-01-11 Created: 2010-01-11 Last updated: 2022-03-01Bibliographically approved
Funk, V. A. & Karis, P. O. (2009). Heterolepis: an unplaced genus. In: Vicki A Funk (Ed.), Systematics, evolution and biogeography of compositae: (pp. 483-486). Vienna: International Association for Plant Taxonomy, University of Vienna
Open this publication in new window or tab >>Heterolepis: an unplaced genus
2009 (English)In: Systematics, evolution and biogeography of compositae / [ed] Vicki A Funk, Vienna: International Association for Plant Taxonomy, University of Vienna , 2009, p. 483-486Chapter in book (Other academic)
Place, publisher, year, edition, pages
Vienna: International Association for Plant Taxonomy, University of Vienna, 2009
National Category
Biological Systematics
Research subject
Systematic Botany
Identifiers
urn:nbn:se:su:diva-34746 (URN)978-3-9501754-3-1 (ISBN)
Available from: 2010-01-11 Created: 2010-01-11 Last updated: 2022-02-25Bibliographically approved
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