Interesting then, that it is in our Dictionary https://www.ispotnature.org/communities/uk-and-ireland/species-dictionary/NHMSYS0000463420/senecio (no Obs)
This is fun Senecio eboracensis R.J.Abbott & A.J.Lowe
Remarkable, has the clinker habitat vanished everywhere so nowhere for it to grow, on other hand Oxford ragwort seems to find plenty of places to thrive different to volcanos.
De-extinction was a new term for me. Dj’s link to gbif shows three plants in 1991 - perhaps the recorder was part of York station maintenance team.
Shows the value of the Seed Bank.
Habitat loss usually brings up visions of wildflower meadows… but clinker habitat loss was as important for this York Ragwort.