Senecio Explained

Senecio ^[1] is a genus of flowering plants in the daisy family (Asteraceae) that includes ragworts and groundsels.

Variously circumscribed taxonomically, the genus Senecio is one of the largest genera of flowering plants.

Description

Morphology

The flower heads are normally rayed with the heads borne in branched clusters, and usually completely yellow, but green, purple, white and blue flowers are known as well.

In its current circumscription, the genus contains species that are annual or perennial herbs, shrubs, small trees, aquatics or climbers. The only species which are trees are the species formerly belonging to Robinsonia occurring on the Juan Fernández Islands.^[2]

Chemistry

Pyrrolizidine alkaloids are found in all Senecio species. These alkaloids serve as a natural biocides to deter or even kill animals that would eat them. Livestock generally do not find them palatable.^[3] Senecio species are used as food plants by the larvae of some Lepidoptera species that have developed tolerance for these alkaloids.

Taxonomy

The traditional circumscription of Senecio is artificial, being polyphyletic, even in its new circumscription which is based on genetic data.^[4] Despite the separation of many species into other genera, the genus still contains species and is one of the largest genera of flowering plants.^[5]

As no morphological synapomorphies are known to determine which species belong to the genus or not, no exact species number is known. The genus has an almost worldwide distribution and evolved in the mid- to late Miocene.^[6]

Phylogeny

Many genera and the whole tribe are in need of revision. Many species currently placed in the genus need to be transferred to other or new genera, and others have been retransferred to Senecio. In its new delimitation the genus is still not monophyletic.

Genera that have been included are the following:

• Aetheolaena
• Culcitum
• Hasteola
• Iocenes B. Nord.
• Lasiocephalus Willd. ex Schltdl.
• Robinsonia

Synonyms

The following genera contain species that are or have been included within Senecio.^[7]

• Antillanthus B. Nord.
• Barkleyanthus H. Rob. & Brettell
• Brachyglottis J. R. Forst. & G. Forst.^[8]
• Canariothamnus B. Nord.
• Curio P.V. Heath
• Dauresia B. Nord. & Pelser
• Dendrophorbium C. Jeffrey
• Dendrosenecio (Hauman ex Hedberg) B. Nord. - Giant groundsels occurring in the high altitude areas of East Africa
• Dorobaea Cass.
• Dresslerothamnus H. Rob.
• Elekmania B. Nord.
• Herreranthus B. Nord.
• Hubertia Bory
• Jacobaea Mill.Leonis B. Nord.
• Ligularia
• Lundinia B. Nord.
• Mesogramma DC.
• Monticalia C. Jeffrey
• Nelsonianthus H. Rob. & Brettell
• Nesampelos B. Nord., nom. inval.
• Oldfeltia B. Nord. & Lundin
• Packera Á. Löve & D. Löve
• Pentacalia Cass.
• Pippenalia McVaugh
• Pittocaulon H. Rob. & Brettell
• Pojarkovia Askerova
• Psacaliopsis H. Rob. & Brettell
• Pseudogynoxys (Greenm.) Cabrera
• Pseudojacobaea (Hook. f.) R. Mathur
• Roldana La Llave
• Sinosenecio B. Nord.
• Synotis (C. B. Clarke) C. Jeffrey & Y. L. Chen
• Telanthophora H. Rob. & Brettell
• Tephroseris (Rchb.) Rchb.
• Vendredia Baill.
• Zemisia B. Nord.^[9]

Etymology

The scientific name, Senecio, means "old man".

Selected species

See main article: List of ''Senecio'' species.

• Senecio ampullaceus — Texas ragwort, Texas squaw-weed, Texas groundsel, clasping-leaf groundsel^[10]
• Senecio angulatus L.f. — creeping groundsel
• Senecio antisanae
• Senecio arborescens
• Senecio barbertonicus Klatt — succulent bush senecio
• Senecio bigelovii — nodding groundsel
• Senecio bosniacus G. Beck — Bosnian ragwort
• Senecio brasiliensis (Spreng.) Less. — flor-das-almas
• Senecio candicans — angel wings
• Senecio cambrensis — Welsh groundsel, Welsh ragwort
• Senecio crassissimus
• Senecio elegans — purple groundsel
• Senecio falklandicus
• Senecio flaccidus Less. — Douglas senecio, threadleaf groundsel, threadleaf ragwort
• Senecio gallicus Chaix — French groundsel
• Senecio glaucus L. — Jaffa groundsel
• Senecio howeanus
• Senecio inaequidens — South African ragwort
• Senecio iscoensis — Hieron.
• Senecio keniophytum
• Senecio lamarckianus
• Senecio leucanthemifolius Poir. — coastal ragwort
• Senecio madagascariensis — Madagascar ragwort
• Senecio macroglossus — Natal ivy, wax ivy
• Senecio neowbsteri Olympic Mountain groundsel
• Senecio patagonicus
• Senecio pauciradiatus
• Senecio pulcher
• Senecio sanmarcosensis
• Senecio scandens — climbing Senecio
• Senecio squalidus — Oxford ragwort
• Senecio trapezuntinus
• Senecio triangularis — arrowleaf groundsel
• Senecio tropaeolifolius — false nasturtium
• Senecio vaginatus
• Senecio vernalis — eastern groundsel
• Senecio viscosus — sticky ragwort
• Senecio vulgaris — common groundsel, old-man-in-the-spring

Formerly in Senecio

• Brachyglottis greyi (as S. greyi)
• Pericallis × hybrida (as S. cruentus)
• Rugelia nudicaulis — Rugels ragwort

Distribution

The genus Senecio is distributed almost worldwide. It is one of the few genera occurring in all five regions with a Mediterranean climate. Furthermore, species are found in mountainous regions, including tropical alpine-like areas.

See also

• Ragwort Control Act 2003

External links

• Web site: Senecio Succulents . 2022-02-18 . Planet Desert.
• Web site: Genus: Senecio L. . 2008-03-06 . Germplasm Resources Information Network (GRIN) . Germplasm Resources Information Network . 2005-10-26 . Taxonomy for Plants . USDA, ARS, National Genetic Resources Program, National Germplasm Resources Laboratory, Beltsville, Maryland. https://web.archive.org/web/20001020120140/http://www.ars-grin.gov/cgi-bin/npgs/html/genus.pl?11063 . 2000-10-20 .
• Web site: Senecio L. . 2008-02-23 . Integrated Taxonomic Information System . Integrated Taxonomic Information System Organization (ITIS) . 20 December 2007. Integrated Taxonomic Information System on-line database.
• Web site: Details for: Senecio . 2008-03-06 . Botanic Garden . Botanical Museum Berlin-Dahlem . amp . Botanical Garden in Berlin . Euro+Med PlantBase . Freie Universität Berlin.
• Web site: Seneco L. . 2008-03-27 . Missouri Botanical Garden . Missouri Botanical Garden . 1753 . Tropicos Nomenclatural Data Base . 2003-07-24 . https://web.archive.org/web/20030724074511/http://mobot.mobot.org/cgi-bin/search_vast?onda=N40035317 . dead .
• Web site: Search Results For 'senecio' . 2008-03-06 . Flora of Israel Online . Hebrew University of Jerusalem . Hebrew University of Jerusalem. https://web.archive.org/web/20100807065430/http://www.flora.huji.ac.il/browse.asp?action=freesearch&q=Senecio . 2010-08-07 .
• Web site: LIST OF ALL PLANTS NAMES -WITH PHOTO S . 2008-03-06 . Jerusalem Botanical Gardens . Jerusalem Botanical Gardens . https://web.archive.org/web/20071004115501/http://www.botanic.co.il/a/holiday/IMGMAP/PlantsNames.HTML#S . 2007-10-04.
• Flora of North America . Flora of North America . Family List: 215. Senecio Linnaeus . 20 . 540, 541, 542, 543, 544, 545, 570, 615 . 2008-03-06 .
• Web site: Senecio L. . 2008-03-06 . Cyrille Chatelain . Laurent Gautier . Raoul Palese . African Flowering Plants Database . Conservatoire et Jardin botaniques de la Ville de Genève.
• Web site: Asteraceae . 2008-03-06 . Instituto Darwinion . PDF . Catálogo de las Plantas Vasculares de la República Argentina. II . . 255 . es . dead . https://web.archive.org/web/20070821142558/http://www.darwin.edu.ar/Publicaciones/CatalogoVascII/asteraceae.zip . August 21, 2007.
• Web site: search term: Senecio . 2008-03-06 . Helen Coleman, FloraBase: Flora of Western Australia . Western Australian Herbarium . 1997-06-18 . Flora Descriptions . . 2010-08-08 . https://web.archive.org/web/20100808011705/http://florabase.calm.wa.gov.au/search/quick?q=Senecio . dead .
• Web site: Senecio L. . 2008-04-01 . Landcare Research . Flora of New Zealand: Taxa . Landcare Research Allan Herbarium and New Zealand Plant Names Database.
• Web site: Search for:genus:Senecio . 2008-02-09 . Species Information . Calflora — 1700 Shattuck Ave. #198, Berkeley, CA 94709.
• Flora of Chile . Flora of North America . Volume 4 Asteraceae Senecio L . 4 . 2008-03-06 .
• Web site: Search Results For Search String: Senecio . 2008-03-06 . Richard Wunderlin or Bruce Hansen . University of South Florida . 2006 . Atlas of Florida Vascular Plants . Institute for Systematic Botany. https://web.archive.org/web/20100702202737/http://florida.plantatlas.usf.edu/Results.aspx . 2010-07-02 .
• Web site: Search terms: Senecio . 2008-03-06 . PlantNET — The Plant Information Network System of Botanic Gardens Trust . Royal Botanic Gardens, Sydney . Botanic Gardens Trust.
• Web site: Senecio L. . 2008-03-06 . University of Wisconsin–Stevens Point . University of Wisconsin–Stevens Point . Robert W. Freckmann Herbarium. https://web.archive.org/web/20060901160409/http://wisplants.uwsp.edu/scripts/photolink.asp?Spcode=SEN- . 2006-09-01 .

Notes and References

1. Sunset Western Garden Book, 1995:606–607
2. Pelser . Pieter B. . Tepe . Eric J. . Kennedy . Aaron H. . Watson . Linda E. . 2013-06-10 . The fate of Robinsonia (Asteraceae): sunk in Senecio, but still monophyletic? . Phytotaxa . 5 . 1 . 31–46 . 10.11646/phytotaxa.5.1.2 . 1179-3163.
3. Book: Taylor, Ronald J. . Sagebrush Country: A Wildflower Sanctuary . Mountain Press Pub. Co . 1994 . 0-87842-280-3 . rev. . Missoula, MT . 156 . en . 25708726 . 1992.
4. Nicodemo G. . Passalacqua . Lorenzo . Peruzzi . Giuseppe . Pellegrino . August 2008 . A Biosystematic Study of the Jacobaea maritima Group (Asteraceae, Senecioneae) in the Central Mediterranean Area . Taxon . 57 . 3 . 893–906 . 27756716 . 10.1002/tax.573018.
5. David G. . Frodin . 2004 . History and concepts of big plant genera . . 53 . 3 . 753–76 . 4135449 . 10.2307/4135449.
6. Patterns and causes of incongruence between plastid and nuclear Senecioneae (Asteraceae) phylogenies. American Journal of Botany. 2010-05-01. 0002-9122. 21622451. 856–873. 97. 5. 10.3732/ajb.0900287. Pieter B.. Pelser. Aaron H.. Kennedy. Eric J.. Tepe. Jacob B.. Shidler. Bertil. Nordenstam. Joachim W.. Kadereit. Linda E.. Watson. free.
7. 10.2307/25065905. 25065905. An ITS Phylogeny of Tribe Senecioneae (Asteraceae) and a New Delimitation of Senecio L. Taxon. 56. 4. 1077. 2007. Pelser. Pieter B.. Nordenstam. Bertil. Kadereit. Joachim W.. Watson. Linda E..
8. Norton . D.A. . Recent changes in the names of New Zealand tree and shrub species . New Zealand Journal of Forestry . 31 . 39–40 . 1986 . 2008-04-10 . 2010-08-16 . https://web.archive.org/web/20100816050902/http://www.nzjf.org/free_issues/NZJF31_3_1986/8B94A164-BF7A-4A5B-A45B-3ACE982D0C7C.pdf . dead .
9. Web site: Genus: Senecio L. . 2008-02-27 . Germplasm Resources Information Network (GRIN) . Germplasm Resources Information Network . 2007-05-04 . Taxonomy for Plants . USDA, ARS, National Genetic Resources Program, National Germplasm Resources Laboratory, Beltsville, Maryland.
10. Web site: Proceed With Caution . 2008-04-10 . Sean Claes . 2007-04-16 . Kyle, Texas Daily Photo.