A spurge of some kind; I cut and painted 5 around trunk of eucalyptus tree which is notorious for dumping garden waste - but I don't know how this species spreads. I removed many of the same in the area over the past years. Within an area of approx 350m2; I mapped the area with Field Maps, Not treated Weeds / Woody Weeds - there were 100's of Privets, Ivy, African Olive, Nettle Tree, Bay Tree, Nandina... I removed the deciduous plants with cut and paint.