Whitetip Nightshade (Solanum chenopodioides), an Argentinian nightshade in the Solanum nigrum complex that has been exported to other wet temperate locales since European colonisation. Reaching Australia in the 20th c as an agricultural contaminant, it should not be confused with the potato bush S. chenopodinum, a Mueller-named Australian native.
Whitetip Nightshade has been recorded fairly extensively in New South Wales since the 1930s, and subsequent to a 1921 record that was made at the Hawkesbury Agricultural College. That early record was presumably made from research material, although the possibility that the college was ground zero for the species in Australia cannot be discounted.
The species was then collected in New Zealand from 1941 and in Queensland beginning in 1966. The first Victorian records were made in 1971-1972 along roads in the Bairnsdale area of East Gippsland; the first metropolitan record, from a Frankston research station in 1975, appears also to have been research material. Whitetip Nightshade seems to have been a major research concern of ‘pest plant’ programs of this period, with the Waite Institute in South Australia also accessioning material in 1966, some thirty years before a naturalised collection would be made in that state.
The first genuine naturalisation record within Melbourne is a 1978 collection from South Melbourne at what is now the major Southbank intersection of City Road and Power Street, but which was then still a dusty industrial street of warehouses and offices. Coincidentally, this collection as described appears to have been made from a gutter immediately up the block from the Melbourne offices of International Harvester.
Requiring damp context, Whitetip Nightshade remains a scattered collection in Victoria, found principally on East Gippsland verges and drainage channels and in Yarra tributaries within inner suburban Melbourne. The photographed plants occupied extensive patches within the ravine of the Merri Creek opposite Rushall Station and at points downstream.