Tag Archives: wildscapes

Senecio

It is night and snow has fallen – blanketing all signs of vegetation in a thick meringue covering that, in a way that is somehow disturbing, reflects the lurid acid yellow of the street lights. Sticks of black shrubs and the naked boughs of plane trees stand out in sharp, angular contrast – Upperthorpe is transformed. All is quiet.

Trudging wearily through the winding ankle-deep paths that criss-cross the disused factory lots, wastelands and brownfield sites, it is hard to imagine that hot day when we followed these self-same lines of passage, punctuated with the sunny yellow flower heads of various nodding ragworts and groundsels … and, in the autumn, the downy, grey, globed heads of seed that earns the genus the name of Senecio – or old man.

The ragworts are asters – and, like the dandelion, they would seem to offer a particular challenge to taxonomists. For one species alone, Oxford ragwort (Senecio squalidus), there are over 21 scientific synonyms and, in addition, the misapplied name of Senecio nebrodensis. A North American species Packera aurea (formerly Senecio aureus), commonly known as Golden Ragwort, has two synonyms and is also commonly known as Life Root, Squaw Weed, Golden Sececio, ragwort, uncum root, waw weed, uncum, false valerian, cough weed, female regulator, cocash weed, ragweed, staggerwort, and St. James wort.

There is, I believe, a much contested myth concerning the number of words for snow in the Eskimo-Aleut languages. Perhaps this discredited idea could be given up, instead, to the English (and Latin) for ragworts?

Senecio is a genus of the daisy family (Asteraceae) that includes ragworts and groundsels. The flower heads are normally rayed, completely yellow, and the heads are borne in branched clusters. Senecio is one of the largest genera of flowering plants and despite the separation of many species into other genera it still contains over 1250 species of varied form, including leaf, stem and tuber succulents, annuals, perennials, aquatics, climbers, shrubs and small trees. Some species produce natural biocides to deter or even kill animals that would eat them.

Oxford ragwort (Senecio squalidus) was first introduced into Britain via Francisco Cupani and William Sherard in the years of their visit 1700, 1701 and 1702 from Sicily – where it lives as a native on volcanic ash – to the Duchess of Beaufort’s garden at Badminton. Later a transfer of the genetic material to the Oxford Botanic Garden by the “Horti Praefectus” (the title still given to the head gardener at the Oxford Botanic Garden), Jacob Bobart the Younger, before his death in 1719. This is also the same year that Bobart retired as Horti Praefectus and 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 the colleges (there is a specific mention in the historical literature of the Bodleian library) and many of the stone walls around the city of Oxford. This gave the plant its common name, “Oxford Ragwort”.

Carolus Linnaeus first described Senecio squalidus 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. James Edward Smith officially identified the escaped Oxford ragwort with its formal name Senecio squalidus in 1800.

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 and the limestone ballast that provides a well-drained medium – an adequate replica of the lava soils of its native home in Sicily.

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

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 Senecio squalidus’  home terrain.

Paul Evans, February 2012