African bush daisy (Euryops chrysanthemoides), a favoured ornamental garden shrub now naturalising into Victorian floodways. Have you seen this plant in suspicious circumstances?
Native to South Africa, this is a bush-sized aster that has been spread previously to East Africa and to New Zealand, with scattered wild instances of the species recorded in NSW, QLD, SA and Norfolk Island since the 1970s. Long-promoted as a bright and drought-tolerant cottage garden selection, Euryops (or its old genus, Gamolepis) has also been criticised as an untidy, straggly shrub that is not worth growing. However you come down on this one, a little more care may be needed in dead-heading and disposal.
Often a canary in the weedy coal mine, RBG-Melbourne appears to have collected suspicious individuals of the species within its own beds in 1996. In 2002, E. chrysanthemoides was found at Leongatha in Gippsland, naturalising in the thousands off an apparently intentional planting around a dam. In 2018, records show the species collected twice in naturalised positions within the metropolitan: on Moonee Ponds Creek at Strathmore Heights, and on Merri Creek in Coburg North.
The plants photographed here (apparently a number of mature stems) were found in Thomastown on the edge of the M80/M31 junction, well-established in a fenced drainage basin where residential storm drains daylight into a brief and marginal channel of the nearby Central Creek (a Merri tributary). The basin apparently collects material from Thomastown’s avid gardeners (and gutterbox tippers), with acres of mint (stay tuned) and a single annual sunflower among the early autumn finds.