Senecio

Senecio
Senecio vulgaris, an illustration from 1885.
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Asterids
Order:	Asterales
Family:	Asteraceae
Subfamily:	Asteroideae
Tribe:	Senecioneae
Subtribe:	Senecioninae
Genus:	Senecio L.
Type species
Senecio vulgaris L.
Species
Some 1500, see text
Synonyms
Dendrosenecio Jacobaea L. Vendredia Baill. Culcitium Humb. & Bonpl

S. aureus Golden Ragwort

S. barbertonicus Succulent Bush Senecio

S. haworthii Woolly Senecio

Senecio jacobaea, Common ragwort

Kleinia neriifolia, Verode

Tephroseris palustris, Swamp Ragwort

Senecio linearifolius, Fireweed Groudsel

Senecio /sᵻˈniːʃi.oʊ/ is a genus of the daisy family (Asteraceae) that includes ragworts and groundsels. The latin name means "old man".

Variously circumscribed, the genus Senecio is one of the largest genera of flowering plants, cleaved or not of species belonging to other genera. The 'traditional' circumscription of Senecio is artificial, being polyphyletic, even in it's new circumscription which is based on genetic data. Despite the separation of many species into other genera the genus still contains c. 1250 species and is one of the largest genera of flowering plants. As no morphological synapomorphies are known to determine which species belong to the genus or not no exact species numbers are known. The genus is nearly worldwide distributed and evolved in the mid to late Miocene.

Some species produce natural biocides (especially alkaloids) to deter or even kill animals that would eat them.

Senecio species are used as food plants by the larvae of some Lepidoptera species — see list of Lepidoptera that feed on Senecio. Pyrrolizidine alkaloids have been found in Senecio nemorensis and in Senecio cannabifolius var. integrilifolius

Morphology

The flower heads are normally rayed, completely yellow, and the heads are borne in branched clusters, but green, purple, white and blue flowers are known as well. In it's current circumscription, the genus contains species that are annual or perennial herbs, shrubs, small trees, aquatics and climbers. The only species which are trees are the species formerly belonging to Robinsonia occurring on the Juan Fernández Islands.

Distribution

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

Phylogeny

Many genera and the whole tribe are in need of revision. Many species actually being placed in the genus need to be transferred to other or new genera, others have been retransferred to Senecio. In it's 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.

• Antillanthus B. Nord.
• Barkleyanthus H. Rob. & Brettell
• Brachyglottis J. R. Forst. & G. Forst.
• Canariothamnus B. Nord.
• Dauresia B. Nord. & Pelser
• Dendrophorbium C. Jeffrey
• Dendrosenecio (Hauman ex Hedberg) B. Nord. - Giant groundsels occuring 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.

Selected species

Main article: List of Senecio species

• Senecio ampullaceus — Texas ragwort, Texas squaw-weed, Texas groundsel, clasping-leaf groundsel
• Senecio angulatus L.f. — Creeping groundsel
• Senecio antisanae
• Senecio arborescens
• Senecio aureus L. — Golden ragwort
  • Packera aurea (L.) A. & D. Löve
• Senecio barbertonicus Klatt — Succulent bush senecio
• Senecio battiscombei
  • Dendrosenecio battiscombei
• Senecio bigelovii - Nodding groundsel
• Senecio brasiliensis (Spreng.) Less. — flor-das-almas
  • Cineraria brasiliensis
• Senecio cambrensis — Welsh groundsel, Welsh ragwort
• Senecio congestus (R. Br.) DC. — Marsh ragwort, Clustered marsh ragwort, marsh fleabane
  • Cineraria palustris
  • Othonna palustris
  • Tephroseris palustris
• Senecio douglasii - Threadleaf groundsel
• Senecio eboracensis Abbott & Lowe — York groundsel
• Senecio flaccidus Less. — Douglas senecio, threadleaf groundsel, threadleaf ragwort
• Senecio gallicus Chaix — Southern ragwort
• Senecio glabellus Poir. — Butterweed
  • Packera glabella (Poir) C. Jeffrey
• Senecio glaucus L. — Jaffa groundsel
• Senecio haworthii — Woolly senecio
• Senecio howeanus
• Senecio iscoensis — Hieron.
• Senecio jacobaea — Now classed as Jacobaea vulgaris.
• Senecio keniensis
  • Dendrosenecio keniensis
• Senecio keniodendron — Giant groundsel
  • Dendrosenecio keniodendron
• Senecio keniophytum
• Senecio kleinia
  • Kleinia neriifolia
• Senecio lamarckianus
• Senecio leucanthemifolius Poir. — Coastal ragwort
• Senecio littoralis
• Senecio mikanioides — Cape ivy, German ivy
  • Delairea odorata
• Senecio nivalis Kunth
• Senecio obovatus Muhl. — Roundleaf ragwort
  • Packera obovata (Muhl. ex Willd.)
• Senecio patagonicus
• Senecio pauciradiatus
• Senecio pulcher
• Senecio rowleyanus — String of pearls
• Senecio sanmarcosensis
• Senecio scandens — German ivy
• Senecio squalidus — Oxford ragwort
• Senecio triangularis - Arrowleaf groundsel
• 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)
• Florist's Cineraria, Pericallis × hybrida (as S. cruentus)
• Rugelia nudicaulis — Rugels ragwort

See also

Ragwort Control Act 2003

External links

Media related to at Wikimedia Commons

• Manual of Gardening (Second Edition) at Project Gutenberg

• Sunset Western Garden Book, 1995:606–607
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