Senecio squalidus

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Senecio squalidus
Senetio rupester.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Asterales
Family: Asteraceae
Genus: Senecio
Species:
S. squalidus
Binomial name
Senecio squalidus
Range map-Senecio squalidus-World.svg
Range of S. squalidus
Synonyms

Senecio nebrodensisauct., non L.
Senecio laciniatusBertol. [2]
Senecio rupestrisWaldst. & Kit. [3]
Senecio squalidusd'Urv.
Senecio squalidusWilld.
Senecio squalidusM.Bieb. [4]
Jacobaea incisaC. Presl
Senecio glaberUcria
Senecio incisus(C. Presl) C. Presl [5]

Contents

Senecio squalidus, known as Oxford ragwort, [6] is a flowering plant in the daisy family Asteraceae. It is a yellow-flowered herbaceous plant, native to mountainous, rocky or volcanic areas, that has managed to find other homes on man-made and natural piles of rocks, war-ruined neighborhoods and dry-stone walls. These habitats resemble its well drained natural rocky homeland. The plants have spread via the wind, rail and the activities of botanists. The travels of this short-lived perennial, biennial, or winter annual make it a good subject for studies of the evolution and ecology of flowering plants.

Description

Like all members of the family Asteraceae, Senecio squalidus has a composite flower head known as a capitulum. What look like single flowers are actually a cluster of florets, each petal or ligule being a flower, or floret, possessing its own stamen and capable of producing the specialized seed of the family Asteraceae, the parachute-like achene. [7]

Oxford ragwort is a short-lived perennial, a biennial, or a winter annual and grows in a branched straggling form to between 1.5 feet (0.5 m) and 3.3 feet (1 m) depending on conditions. S. squalidus prefers dry, disturbed places, cultivated and waste ground, walls and railway banks. [3] [8] It flowers from March [9] to December [8] and reproduces from seed. [3]

Leaves and stems
S. squalidus leaves are alternate, glossy, almost hairless and variable in form from deeply pinnately lobed to undivided with only the lower leaves being stalked. Stems and leaves resemble those of the common groundsel ( Senecio vulgaris ) [3] [8] with the exception that their lobes are more widely spaced. [10]
Inflorescence
S. squalidus has larger capitula than Senecio jacobaea and a more spreading habit. [9] Yellow capitula of 10-14 petals in loose clusters. They are pollinated by insects. Ray corollas .3 inches (8 mm) to .6 inches (15 mm) long, .08 inches (2 mm) to .16 inches (4 mm) wide. [8]
Oxford ragwort is self-incompatible and needs pollen from other plants with different self-incompatibility alleles; [11]

[12] [13] its own flowers possess a stigma with characteristics of both the “dry” and “wet” types. [14]

The fruiting heads are often nodding. [3]
Seeds
Each pollinated Oxford ragwort floret matures into a bell to cylindrical shaped indehiscent achene, the shallowly ribbed fruit is light brown in colour and .06 inches (1.5 mm) to .12 inches (3 mm) long. [8] Each plant can produce approximately 10,000 fruits during the year. [15]

As a Senecio and a diploid Senecio squalidus is part of a species group along with S. flavus , S. gallicus , S. glaucus and S. vernalis , which are widespread geographically and interesting for the study of genetic differences in relation to the environment and plant evolution. [16]

History

Senecio squalidus growing on walls in Liverpool. Oxford ragwort in Liverpool-cropped.jpg
Senecio squalidus growing on walls in Liverpool.

This Senecio was introduced into Britain via Francesco Cupani and William Sherard in the years of their visit 1700, 1701 and 1702 from Sicily [17] where it lives as a native on volcanic ash [15] to the Duchess of Beaufort's garden at Badminton House. Later a transfer of the plant material to the Oxford Botanic Garden by the "Horti Praefectus" Jacob Bobart the Younger took place before his death in 1719, [18] providing perhaps a good indication of when this species of ragwort and other invasive species might have "escaped" and started to make their home in the greater British Isles. The Sicilian ragwort escaped into the wild and grew in the stonework of Oxford colleges (with the specific mention of the Bodleian Library [9] ) and many of the stone walls around the city of Oxford. This gave the plant its common name, "Oxford Ragwort". [19]

Carl Linnaeus first described Senecio squalidus [20] in 1753, although there is a dispute as to whether the material came from the Botanic Garden or from walls in the city; the taxonomy for this species is further complicated by the existence of species with a similar morphology in continental Europe. [18]

James Edward Smith officially identified the escaped Oxford ragwort with its formal name Senecio squalidus in 1800. [18]

The vortex of air following the express train carries the fruits in its wake. I have seen them enter a railway-carriage window near Oxford and remain suspended in the air in the compartment until they found an exit at Tilehurst.

George Druce, 1927 [18]

During the Industrial Revolution, Oxford became connected to the railway system and the plant gained a new habitat in the railway lines clinker beds, gradually spreading via the railway to other parts of the country. The process was accelerated by the movement of the trains [19] and the limestone ballast that provides a well-drained medium which is an adequate replica of the lava-soils of its native home in Sicily. [18] [21]

During the 20th century it continued to spread along railway lines and found a liking for waste places and bombed sites after World War II which have a lot in common with the volcanic regions of its home. [9]

Recently, this and other Senecio species and their differing tastes for self-incompatibility and self-compatibility have been the subject of study for the purposes of understanding the evolution of plant species as the genus finds new homes and pollen partners throughout the world:

Distribution

Senecio squalidus grows on scree in mountainous regions of native range, [3] and earned its common name Oxford ragwort for its willingness and ability to grow in similar habitat elsewhere in the world. [18]

Native range of S. squalidus. Range map-Senecio squalidus-Native.svg
Native range of S. squalidus.

Native [22] [23]

Senecio squalidus is considered to be a native of New Brunswick and Nova Scotia, Canada by the USDA Natural Resources Conservation Service while the same USDA other resource Germplasm Resources Information Network considers it to be native to Austria, Czech Republic, Slovakia, Germany, Switzerland, Albania, Bulgaria, Greece, Crete, Italy, Sardinia, Sicily, Romania, Bosnia and Herzegovina, Croatia, Montenegro, North Macedonia, Serbia, Slovenia.

Current [3] [23] [24] [25]

Africa
Northern Africa: Morocco
America
North America: New Brunswick, Nova Scotia, British Columbia, California
Europe
Northern Europe: Denmark, Germany, Republic of Ireland, Netherlands, Norway, Sweden, United Kingdom
Middle Europe: Austria, Czech Republic, Hungary, Slovakia, Switzerland
East Europe: Poland,
Southeastern Europe: Albania, Bosnia and Herzegovina, Bulgaria
Southwestern Europe: France, Spain
South Europe: Croatia, Crete, Greece, Italy, North Macedonia, Romania, Sardinia, Serbia, Sicily, Slovenia

Range Maps

Predators

S. squalidus is a food plant for some insects, for example:

Flies

Gall flies (Diptera: Tephritidae):

Fungi

Most Senecio, including S. squalidus are susceptible to rust and other fungus and mildews: [26]

Rust fungus Uredinales
White rust Peronosporales
Sac fungus Ascochyta, Pezizomycetes
Powdery Mildew Erysiphales

Synonyms and misapplied names

Misapplied names

Related Research Articles

<span class="mw-page-title-main">Asteraceae</span> Large family of flowering plants

Asteraceae is a large family of flowering plants that consists of over 32,000 known species in over 1,900 genera within the order Asterales. The number of species in Asteraceae is rivaled only by the Orchidaceae, and which is the larger family is unclear as the quantity of extant species in each family is unknown. The Asteraceae were first described in the year 1740 and given the original name Compositae. The family is commonly known as the aster, daisy, composite, or sunflower family.

<i>Senecio</i> Genus of flowering plants in the daisy family Asteraceae

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

<i>Jacobaea vulgaris</i> Flowering plant, daisy family Asteraceae

Jacobaea vulgaris, syn. Senecio jacobaea, is a very common wild flower in the family Asteraceae that is native to northern Eurasia, usually in dry, open places, and has also been widely distributed as a weed elsewhere.

<i>Senecio vulgaris</i> Species of flowering plant in the daisy family Asteraceae

Senecio vulgaris, often known by the common names groundsel and old-man-in-the-spring, is a flowering plant in the family Asteraceae. It is an annual herb, native to the Palaearctic and widely naturalised as a ruderal species in suitable disturbed habitats worldwide.

Backcrossing is a crossing of a hybrid with one of its parents or an individual genetically similar to its parent, to achieve offspring with a genetic identity closer to that of the parent. It is used in horticulture, animal breeding, and production of gene knockout organisms.

<i>Jacobaea maritima</i> Species of flowering plant

Jacobaea maritima, commonly known as silver ragwort, is a perennial plant species in the genus Jacobaea in the family Asteraceae, native to the Mediterranean region. It was formerly placed in the genus Senecio, and is still widely referred to as Senecio cineraria; see the list of synonyms (right) for other names.

<span class="mw-page-title-main">Pseudanthium</span> Type of inflorescence, clusters of flowers

A pseudanthium is an inflorescence that resembles a flower. The word is sometimes used for other structures that are neither a true flower nor a true inflorescence. Examples of pseudanthia include flower heads, composite flowers, or capitula, which are special types of inflorescences in which anything from a small cluster to hundreds or sometimes thousands of flowers are grouped together to form a single flower-like structure. Pseudanthia take various forms. The real flowers are generally small and often greatly reduced, but the pseudanthium itself can sometimes be quite large.

<i>Senecio cambrensis</i> Species of flowering plant

Senecio cambrensis is a flowering plant of the family Asteraceae. It is endemic to Great Britain and currently known only from North Wales. It is a recently evolved plant that arose as a result of hybridization between two related species.

<i>Packera aurea</i> Species of flowering plant

Packera aurea, commonly known as golden ragwort or simply ragwort, is a perennial flower in the family Asteraceae.

<i>Senecio ampullaceus</i> Species of plant

Senecio ampullaceus, also known as Texas ragwort, Texas squaw-weed, Texas groundsel, and Texas butterweed, is a species of Senecio in the family Asteraceae, receiving its Latin name ampullaceus from its flask shaped flower-head. It is recommended for landscape use in its native Texas.

<i>Senecio eboracensis</i> Species of flowering plant in the daisy family Asteraceae

Senecio eboracensis, the York groundsel or York radiate groundsel, is a flowering plant in the daisy family Asteraceae. It is a hybrid between a native and a non-native introduced species, which naturalised in England but the population failed to sustain itself. It was brought back by captive cultivation. It is a self-pollinating hybrid species of ragwort and one of only six new plant species to be discovered in either the United Kingdom or North America in the last 100 years.

<i>Tephroseris palustris</i> Species of flowering plant in the daisy family Asteraceae

Tephroseris palustris, also known by its common names swamp ragwort, northern swamp groundsel, marsh fleabane, marsh fleawort, clustered marsh ragwort and mastodon flower, a herbaceous species of the family Asteraceae. It can be seen most easily when its bright yellow umbel flowers appear from May to early July standing 3 to 4 feet along marshes, stream banks and slough areas where it likes to grow.

<i>Senecio vernalis</i> Species of flowering plant

Senecio vernalis is one of the European species of Senecio, an annual that is also known as eastern groundsel. While it has been long classified as Senecio vernalis, this species has more recently been described as a subspecies of Senecio leucanthemifolius and is now included by some in that species.

<i>Senecio leucanthemifolius</i> Species of flowering plant

Senecio leucanthemifolius is a plant common in sea-side in Mediterranean area.

<i>Senecio glaucus</i> Species of flowering plant

Senecio glaucus is an annual member of the Asteraceae and species of the genus Senecio. It is found from the western Mediterranean to Central Asia in sandy, well-drained soil, particularly coastal and desert dunes.

<i>Jacobaea erucifolia</i> Species of flowering plant

Jacobaea erucifolia, the hoary ragwort is a species of flowering plant in the genus Jacobaea and the family Asteraceae. It is a perennial or rhizomatous geophyte native to temperate Eurasia, ranging from Europe to Siberia, Turkey, Iran, Central Asia, Mongolia, China, and Japan.

<i>Senecio inaequidens</i> Species of flowering plant in the daisy family Asteraceae

Senecio inaequidens, known as narrow-leaved ragwort and South African ragwort, is a species of flowering plant in the daisy family Asteraceae.

<i>Senecio ovatus</i> Species of flowering plant

Senecio ovatus, common name wood ragwort, is a perennial herbaceous plant belonging to the family Asteraceae.

References

  1. ↑ Natural Resources Conservation Service (NRCS). "PLANTS Profile, Senecio squalidus L." The PLANTS Database. United States Department of Agriculture . Retrieved 14 February 2008.
  2. 1 2 Royal Botanic Garden Edinburgh. "Flora Europaea Search Results matching squalidus and Senecio" . Retrieved 14 February 2008.
  3. 1 2 3 4 5 6 7 8 California Department of Food and Agriculture. "Genus Senecio". Encycloweedia. State of California. Retrieved 13 February 2008.
  4. 1 2 The International Plant Names Index. "whole name = Senecio squalidus". Plant Names. Retrieved 14 February 2008.
  5. 1 2 Botanic Garden & Botanical Museum Berlin-Dahlem. "Details for: Senecio squalidus". Euro+Med PlantBase. Freie Universität Berlin . Retrieved 23 April 2008.
  6. ↑ BSBI List 2007 (xls). Botanical Society of Britain and Ireland. Archived from the original (xls) on 26 June 2015. Retrieved 17 October 2014.
  7. ↑ Dr. Gerald (Gerry) Carr, University of Hawaii, Botany Department. "Asteraceae (Compositae)". Vascular Plant Family Systematic Index. Retrieved 14 February 2008.{{cite web}}: CS1 maint: multiple names: authors list (link)
  8. 1 2 3 4 5 Brickfields Country Park (24 December 2007). "Oxford Ragwort - Senecio squalidus". Ask Brickfields Country Park a question. Retrieved 14 February 2008.
  9. 1 2 3 4 Peter Llewellyn (23 August 2004). "Senecio squalidus Oxford ragwort". Wild Flowers of the British Isles. Wild Flower Society. Retrieved 12 February 2008.
  10. ↑ Department for Environment, Food and Rural Affairs (7 March 2000). "Identification of injurious weeds" (PDF). Farming: wildlife and plants. United Kingdom Government . Retrieved 15 February 2008.
  11. ↑ Hiscock, S.J. (2000). "Genetic control of self-incompatibility in Senecio squalidus L. (Asteraceae): a successful colonizing species". Heredity . 85 (1): 85, 10–19. doi:10.1046/j.1365-2540.2000.00692.x. PMID   10971686. S2CID   31529463.
  12. ↑ Hiscock, S.J. (2000). "Self-incompatibility in Senecio squalidus L. (Asteraceae)". Annals of Botany: 85, 181–190.
  13. ↑ Alexandra Allen. "Identification of genes regulating self-incompatibility in Senecio squalidus (Asteraceae)". University of Bristol, School of Biological Sciences. Retrieved 14 February 2008.
  14. ↑ Simon J. Hiscock; Karin Hoedemaekers; William E. Friedman; Hugh G. Dickinson (January 2002). "The stigma surface and pollen-stigma interactions in Senecio squalidus L. (Asteraceae) following cross (compatible) and self (incompatible) pollinations" (PDF). International Journal of Plant Sciences. 163 (1). University of Chicago, Hyde Park, Chicago: The University of Chicago Press: 1–16. doi:10.1086/324530. S2CID   84275629. 1058-5893/2002/16301-0001. Archived from the original (PDF) on 27 February 2020.
  15. 1 2 "Details for Senecio squalidus L." The National Biodiversity Network's Species Dictionary. Natural History Museum, London. 12 August 1994. Retrieved 14 February 2008.
  16. ↑ Peter Hollingsworth; Richard M. Bateman; Richard Gornall (1999). "Monophyly populations and species". Molecular systematics and plant evolution. CRC Press. pp. 504 pages. ISBN   0-7484-0908-4 . Retrieved 23 April 2008.
  17. ↑ University of Catania. "Monti Rossi" (in Italian). Retrieved 15 February 2008.
  18. 1 2 3 4 5 6 7 Harris, S.A. (2002). "Introduction of Oxford Ragwort, Senecio squalidus L. (Asteraceae), to the United Kingdom" (PDF). Watsonia . 24. Botanical Society of the British Isles: 31–43. Retrieved 14 February 2008.
  19. 1 2 Plant reproduction and speciation group, University of Bristol. "The Oxford Ragwort Story". University of Bristol, School of Biological Sciences. Archived from the original on 11 April 2009. Retrieved 13 February 2008.
  20. ↑ Swedish Museum of Natural History (20 August 2003). "Senecio squalidus L." Linnean herbarium (S-LINN). Retrieved 14 February 2008.
  21. ↑ Chris Gliddon (12 February 1998). "Plant Invasion and Inter-Specific Hybridization". The impact of hybrids between genetically modified crop plants and their related species: biological models and theoretical perspectives. Guide to Risk Assessment and Biosafety in Biotechnology, GRABB, United Nations Environment Programme . Retrieved 14 February 2008.
  22. ↑ Natural Resources Conservation Service (NRCS). "PLANTS Profile, Nativity of Senecio squalidus L." The PLANTS Database. United States Department of Agriculture . Retrieved 14 February 2008.
  23. 1 2 "Senecio squalidus". Germplasm Resources Information Network . Agricultural Research Service, United States Department of Agriculture . Retrieved 14 February 2008.
  24. ↑ Global Biodiversity Information Facility. "Occurrence search Classification includes Species: Senecio squalidus ". Species Data. GBIF Data Portal. Retrieved 14 February 2008.
  25. ↑ "Senecio squalidus". Artículo de la Enciclopedia Libre Universal en Español (in Spanish). Retrieved 14 February 2008.
  26. 1 2 "Senecio squalidus L. (Oxford Ragwort)". BioImages: The Virtual Field-Guide (UK). Archived from the original on 7 September 2008. Retrieved 14 February 2008.
  27. ↑ Missouri Botanical Garden. "TROPICOS Web display Senecio squalidus L." Nomenclatural and Specimen Data Base. Missouri State Library. Retrieved 14 February 2008.

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