Senecio cambrensis
Encyclopedia
Senecio cambrensis is a flowering plant
of the family Asteraceae
. It is endemic
to the United Kingdom
and currently known only from North Wales
. It is a recently evolved plant which arose suddenly as a result of hybridization between two related species.
) grow alongside each other. Sometime in the early 20th century, an accidental doubling of the number of chromosomes in an S. × baxteri plant led to the formation of a new fertile species, Welsh groundsel.
in Flintshire
, north-east Wales
. The species was described in 1955 by Effie M. Rosser of Manchester Museum
using material from the site. It was later found at a number of sites across the north-east of Wales including Chirk
, Brymbo
, Queensferry
and Colwyn Bay
and a herbarium
specimen was discovered which had been collected at Brynteg in 1925.
In England
it was reported from Shropshire
and an introduced population appeared in Wolverhampton
. The Shropshire record is now thought to be erroneous and the Wolverhampton plants have disappeared. There are no recent records from England.
In 1982, Welsh groundsel was discovered at several sites around Edinburgh
, Scotland
. This population arose independently from the Welsh population; it is believed to date from at least 1974 but now appears to have disappeared with no records since 1993.
Typical habitats of the species include waste ground, roadsides and cracks in walls and pavements.
which reaches a height of 30 (sometimes 50) centimetres. The stem and leaves have few or no hairs. The leaves are deeply lobed, the lower ones have stalks while the upper leaves are attached directly to the stem. The flower heads
are cylindrical and usually have 8 to 15 yellow ray florets ("petals") although some are rayless. The ray florets vary in length but are most commonly 4 to 7 mm long. The pollen
grains are 30 to 36 micrometre
s across and usually have 4 pores.
Flowering plant
The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...
of the family Asteraceae
Asteraceae
The Asteraceae or Compositae , is an exceedingly large and widespread family of vascular plants. The group has more than 22,750 currently accepted species, spread across 1620 genera and 12 subfamilies...
. It is endemic
Endemic (ecology)
Endemism is the ecological state of being unique to a defined geographic location, such as an island, nation or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, all species of lemur are endemic to the...
to the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
and currently known only from North Wales
North Wales
North Wales is the northernmost unofficial region of Wales. It is bordered to the south by the counties of Ceredigion and Powys in Mid Wales and to the east by the counties of Shropshire in the West Midlands and Cheshire in North West England...
. It is a recently evolved plant which arose suddenly as a result of hybridization between two related species.
Origin
Welsh groundsel is an allopolyploid, a plant which contains sets of chromosomes originating from two different species. Its ancestor was Senecio × baxteri, an infertile hybrid which can arise spontaneously when the closely related groundsel (Senecio vulgaris) and Oxford ragwort (Senecio squalidusSenecio squalidus
Oxford Ragwort , is a member of the Senecio genus 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...
) grow alongside each other. Sometime in the early 20th century, an accidental doubling of the number of chromosomes in an S. × baxteri plant led to the formation of a new fertile species, Welsh groundsel.
Distribution and habitat
It was first discovered in 1948 by Horace E. Green at FfrithFfrith
Ffrith is a small village in the community of Llanfynydd in Flintshire, north-east Wales.-Name:The name Ffrith reflects a spelling and pronunciation particular to Flintshire: it is derived from a North Welsh word meaning variously a "pasture", "enclosure" or "forest" and borrowed originally from...
in Flintshire
Flintshire
Flintshire is a county in north-east Wales. It borders Denbighshire, Wrexham and the English county of Cheshire. It is named after the historic county of Flintshire, which had notably different borders...
, north-east Wales
Wales
Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...
. The species was described in 1955 by Effie M. Rosser of Manchester Museum
Manchester Museum
The Manchester Museum is owned by the University of Manchester. Sited on Oxford Road at the heart of the university's group of neo-Gothic buildings, it provides access to about six million items from every continent and serves both as a resource for academic research and teaching and as a regional...
using material from the site. It was later found at a number of sites across the north-east of Wales including Chirk
Chirk
Chirk is a small town and local government community, the lowest tier of local government, part of Wrexham County Borough in Wales. It has a population of over 4,000....
, Brymbo
Brymbo
Brymbo is a local government community, the lowest tier of local government, part of Wrexham County Borough in Wales. It is a village situated in the hilly country to the west of Wrexham town, largely surrounded by farmland....
, Queensferry
Queensferry, Flintshire
Queensferry is a town in Flintshire, North Wales, lying on the River Dee near the border with England.Queensferry lies along the B5441 and B5129 roads, and is bypassed by the A494 dual carriageway. It is contiguous with Deeside...
and Colwyn Bay
Colwyn Bay
- Demography :Prior to local government reorganisation on 1 April 1974 Colwyn Bay was a municipal borough with a population of c.25,000, but in 1974 this designation disappeared leaving five separate parishes, known as communities in Wales, of which the one bearing the name Colwyn Bay encompassed...
and a herbarium
Herbarium
In botany, a herbarium – sometimes known by the Anglicized term herbar – is a collection of preserved plant specimens. These specimens may be whole plants or plant parts: these will usually be in a dried form, mounted on a sheet, but depending upon the material may also be kept in...
specimen was discovered which had been collected at Brynteg in 1925.
In England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
it was reported from Shropshire
Shropshire
Shropshire is a county in the West Midlands region of England. For Eurostat purposes, the county is a NUTS 3 region and is one of four counties or unitary districts that comprise the "Shropshire and Staffordshire" NUTS 2 region. It borders Wales to the west...
and an introduced population appeared in Wolverhampton
Wolverhampton
Wolverhampton is a city and metropolitan borough in the West Midlands, England. For Eurostat purposes Walsall and Wolverhampton is a NUTS 3 region and is one of five boroughs or unitary districts that comprise the "West Midlands" NUTS 2 region...
. The Shropshire record is now thought to be erroneous and the Wolverhampton plants have disappeared. There are no recent records from England.
In 1982, Welsh groundsel was discovered at several sites around Edinburgh
Edinburgh
Edinburgh is the capital city of Scotland, the second largest city in Scotland, and the eighth most populous in the United Kingdom. The City of Edinburgh Council governs one of Scotland's 32 local government council areas. The council area includes urban Edinburgh and a rural area...
, Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
. This population arose independently from the Welsh population; it is believed to date from at least 1974 but now appears to have disappeared with no records since 1993.
Typical habitats of the species include waste ground, roadsides and cracks in walls and pavements.
Description
The plant is intermediate in appearance between its parents, groundsel and Oxford ragwort. It is an erect annual plantAnnual plant
An annual plant is a plant that usually germinates, flowers, and dies in a year or season. True annuals will only live longer than a year if they are prevented from setting seed...
which reaches a height of 30 (sometimes 50) centimetres. The stem and leaves have few or no hairs. The leaves are deeply lobed, the lower ones have stalks while the upper leaves are attached directly to the stem. The flower heads
Head (botany)
The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization....
are cylindrical and usually have 8 to 15 yellow ray florets ("petals") although some are rayless. The ray florets vary in length but are most commonly 4 to 7 mm long. The pollen
Pollen
Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes . Pollen grains have a hard coat that protects the sperm cells during the process of their movement from the stamens to the pistil of flowering plants or from the male cone to the...
grains are 30 to 36 micrometre
Micrometre
A micrometer , is by definition 1×10-6 of a meter .In plain English, it means one-millionth of a meter . Its unit symbol in the International System of Units is μm...
s across and usually have 4 pores.