Senecio eboracensis

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Senecio eboracensis
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. eboracensis
Binomial name
Senecio eboracensis
Abbott & Lowe [1]
Range map-Senecio eboracensis-Great Britain.svg
Range of Senecio eboracensis in Great Britain.

Senecio eboracensis, the York groundsel or York radiate groundsel, is a flowering plant in the daisy family Asteraceae. It's the first ever species to be brought back from extinction in Britain. [2] It is a self-pollinating hybrid species of ragwort [3] and one of only six new plant species to be discovered in either the United Kingdom or North America in the last 100 years. [4]

Contents

The plant was first discovered in York, England in 1979 and last seen in the wild in 1991. A survey by UK government advisory body Natural England found it was driven to extinction by 2000, partly due to the use of weedkiller. [5] Seeds of the plant were stored at the Millennium Seed Bank, successfully germinated, and reintroduced to York in 2023. [6]

Description

York radiate groundsel is an annual herbaceous plant that sets its seed within the 3 months [4] that it takes this plant to mature from germination to the upwards of 16 inches (41 cm) high adult plant. With yellow daisy-like flowers from its Sicilian parent ( S. squalidus ) but also with the less-promiscuous habits of its native parent ( S. vulgaris ), this member of the genus Senecio is morphologically distinct from related species. [3]

Leaf shapes of S. eboracensis Senecio eboracensis leaf linedrawing.svg
Leaf shapes of S. eboracensis
Leaves and stems

S. eboracensis have large many lobed leaves divided into slender segments, the clefts not reaching the midrib. The stems are mostly erect to ascending with an occasional horizontal base section up to 2 inches (5 cm) with 'adventitious roots' at base. The upper and lower leaves petiolate and lobes appearing at quarter whole leaf lengths along the midrib. The upper leaves are generally more deeply lobed and in lobed pairs. Leaves on plants grown in fertile soils or in greenhouses can be much more luxurious and more highly dissected (or more finely divided into slender segments) up to 7 inches (18 cm) x 3.5 inches (9 cm) with lobes appearing at fifth whole leaf lengths along the midrib. Leaf edges throughout are dentate or sometimes divided into lobes. [3]

Flowers

York groundsel has flower-heads that are more showy than those of its parent groundsel. The flower-head, found at the tips of the plants (apical) appearing in clusters (an inflorescence) usually consist of three to seven florets grouped in a corymb; at first dense and leafy but eventually less dense with peduncles 5 to 20 millimeters (0.2 to 0.8 in) which get longer when fruiting (up to 25 mm (1 in)). The flower-head is broadly cylindrical 10×4 millimeters (0.4×0.16 in), becoming slightly bell shaped) when the bright yellow ray florets open. Involucral bracts sparse (4-8), elongated (3.54 mm), usually without black tips. The ligules are narrow, 5 to 7 millimeters (0.2 to 0.24 in) long and 1.5 millimeters (0.06 in) wide), occasionally becoming revolute. [3]

Seeds

The achenes can be 2.5 to 3.5 millimeters (0.1 to 0.15 in) long, are straight and shallowly grooved. The smooth ribs are hairless while the grooves are covered with hairs. The silky white, umbrella-like pappus readily detaches from the fruit when ripe. [3]

Name

The word Eboracum, the classical name of York, was chosen in the year 2000 to describe this tetraploid hybrid derivative informally named 'York radiate groundsel' at the time a formal description was made. [3]

Distribution

York groundsel occurs on disturbed ground, car park perimeters, pavement cracks and other urban/industrial sites; specifically in disturbed areas near to the railways in York, England. [3]

One of the parents Senecio vulgaris is a native to the area [7] while the other parent Senecio squalidus was introduced from Mount Etna in Sicily in 1690 to the Oxford Botanic Garden in Oxford, England and was soon spreading along the railways and throughout the country. [8]

Evolution

Senecio eboracensis is a hybrid species whose parents are the self-incompatible and promiscuous Sicilian Senecio squalidus (also known as Oxford ragwort) [8] and the self-compatible and tenacious Senecio vulgaris (also known as Common groundsel). Like S. vulgaris, S. eboracensis is self-compatible but shows little or no natural crossing with its parent species and is therefore reproductively isolated, indicating that strong breeding barriers exist between this new hybrid and its parents. [9] It is thought to have resulted from backcrossing of the F1 hybrid of its parents to S. vulgaris. [3] S. vulgaris is native to Britain, while S. squalidus was introduced from Sicily in the early 18th century; [3] therefore, S. eboracensis has speciated from those two species within the last 300 years.

Other hybrids descended from the same two parents are known. Some are infertile, such as S. x baxteri. Other fertile hybrids are also known, including S. vulgaris var. hibernicus (which has been accepted as a synonym for S. vulgaris [10] ), now common in Britain, and the allohexaploid S. cambrensis , which according to molecular evidence probably originated independently at least three times in different locations. [3] Morphological and genetic evidence support the status of S. eboracensis as separate from other known hybrids. [3] [9]

See also

Related Research Articles

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

The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae were first described in the year 1740. 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.

<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> Species of flowering plant in the 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>Packera</i> Genus of flowering plants in the family Asteraceae

Packera is a genus of about 75 species of plants in the daisy family, Asteraceae. Most species are commonly called ragworts or grounsels. Its members were previously included in the genus Senecio, but were moved to a different genus based on chromosome numbers, a variety of morphological characters, and molecular phylogenetic evidence.

<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.

<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. It is also known as golden groundsel, squaw weed, life root, golden Senecio, uncum, uncum root, waw weed, false valerian, cough weed, female regulator, cocash weed, ragweed, staggerwort, and St. James wort.

<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 viscosus</i> Species of flowering plant

Senecio viscosus is a herbaceous annual plant of the genus Senecio. It is known as the sticky ragwort, sticky groundsel or stinking groundsel.

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

Senecio squalidus, known as Oxford ragwort, 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 even on 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.

Ragwort may refer to a number of plant species:

<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 fremontii</i> Species of flowering plant

Senecio fremontii, the dwarf mountain ragwort, is a species of the family Asteraceae. It takes its scientific name from John C. Frémont.

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

Senecio madagascariensis, also known as Madagascar ragwort, is a species of the genus Senecio and family Asteraceae that is native to Southern Africa. Other common names include Madagascar groundsel and fireweed. It has been included on the noxious weeds list for Hawaii and the reject list for Australia. S.madagascariensis is the diploid cytotype of S.inaequidens.

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

Senecio triangularis, known as arrowleaf ragwort, arrowleaf groundsel and arrowleaf butterweed, is a species of the genus Senecio and family Asteraceae.

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

Senecio sylvaticus is a species of flowering plant in the aster family. It is variously known as the woodland ragwort, heath groundsel, or mountain common groundsel. It is native to Eurasia, and it can be found in other places, including western and eastern sections of North America, as an introduced species and an occasional roadside weed. It grows best in cool, wet areas. It is an annual herb producing a single erect stem up to 80 centimeters tall from a taproot. It is coated in short, curly hairs. The toothed, deeply lobed leaves are up to 12 centimeters long and borne on petioles. They are evenly distributed along the stem. The inflorescence is a wide, spreading array of many flower heads, each lined with green- or black-tipped phyllaries. The heads contain yellow disc florets and most have very tiny yellow ray florets as well.

References

  1. Botanic Garden & Botanical Museum Berlin-Dahlem. "Details for: Senecio eboracensis". Euro+Med PlantBase. Freie Universität Berlin . Retrieved 2008-02-12.
  2. Barkham, Patrick (2023-05-27). "York groundsel blooms again in Britain's first-ever de-extinction event". The Guardian. ISSN   0261-3077 . Retrieved 2023-05-27.
  3. 1 2 3 4 5 6 7 8 9 10 11 Abbot, R.J.; Lowe, A.J. (2003). "A new British species, Senecio eboracensis (Asteraceae), another hybrid derivative of S. vulgaris L. and S. squalidae L." (PDF). Watsonia. 24: 375–388. Archived from the original (PDF) on 2007-09-27. Retrieved 2007-07-15.
  4. 1 2 Martin Wainwright (2003-02-20). "Blooming unexpected". Education Guardian. The Guardian. Retrieved 2008-02-13.
  5. "Weedkiller blamed for loss of York Groundsel". York Press. 2010-03-12. Retrieved 2023-05-27.
  6. Barkham, Patrick (2023-05-27). "York groundsel blooms again in Britain's first-ever de-extinction event". The Guardian. ISSN   0261-3077 . Retrieved 2023-05-27.
  7. "Senecio vulgaris". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA). Retrieved 2008-01-27.
  8. 1 2 Plant reproduction and speciation group, University of Bristol. "The Oxford Ragwort Story". University of Bristol, School of Biological Sciences. Retrieved 2008-02-13.
  9. 1 2 Lowe, A.J.; Abbott, R.J. (May 2004). "Reproductive isolation of a new hybrid species, Senecio eboracensis Abbott & Lowe (Asteraceae)". Heredity . 92 (5): 386–395. doi: 10.1038/sj.hdy.6800432 . PMID   15014422.
  10. Missouri Botanical Garden. "TROPICOS Web display Senecio vulgaris L." Nomenclatural and Specimen Data Base. Missouri State Library. Retrieved 2008-02-01.

Wikispecies-logo.svg Data related to Senecio eboracensis at Wikispecies Commons-logo.svg Media related to Senecio eboracensis at Wikimedia Commons Commons-logo.svg Media related to Tyria jacobaeae at Wikimedia Commons

Further reading