Thistles and brooms, ryegrass and goosegrass and vetch.
The more I learn about the weeds that infest our paddocks, the more I find myself spotting them when we travel.
Fancy names, multiple names, “Great Mullein”, “Salvation Jane”, “Horehound” and “Pellitory of the Wall”.
Some are clearly at home, well controlled by the climate, or insects or other features that keep them in check. Others are clearly weeds to the places we visit also.
Some are surrounded by little fences, protected plants in their place of origin, hardly surviving their own onslaught of invaders, like the pine trees of the Madonie forest in Sicily, a tiny patch of grass on the old castle mount in Cambridge, or what looked like serrated tussock in a municipal planter in Malta.
Some of our Esdale weeds were Australianised by the homesick, like Scotch thistles and Scotch broom.
Some were brought for their medicinal qualities, like variegated thistles or St John’s Wort.
Others were brought even more deliberately, as part of agricultural projects, like African Lovegrass, a contamination of Consol grass, to be used for erosion control.
Blackberries, dandelions, and nettles for food.
Hawthorn for hedges.
All necessary to people who could see no potential in the unknown Australian plants around them.
All essential so the invaders could feel at home, by bringing more invasives with them.
Left behind was the sense of living together with the land, keeping the seasons according to ancient knowledge, like the swallow return in Sicily, which helped farmers time their crop planting.
Such traditional knowledge existed in Australia too, before Europeans.
In the meantime, Australian plants have joined the worldwide whirlwind of plant mixing, especially eucalypts planted for timber and windbreaks.
The eucalypts in Sicily looked particularly miserable, as invasives sometimes do when a single predator makes it across the big divide and begins to control them again. Sicily certainly needs trees (the ones that weren’t chopped down by the ancient Greeks were removed by the Normans), but Sydney Blue Gums were a strange and now unhealthy choice.
At least, as we wandered the hills of Sicily, Cornwall, Tamil Nadhu, or wherever, there were some things that haven’t joined our Esdale irritations.
Or not yet, anyway.
During the first year I was collecting data it rained a lot, the river levels were high and the readings were very clean. Since last year however, the river has been mostly low, and the nitrate levels are generally off the charts high. 
One of the things I love about gardening is the unexpected arrivals. After being away for three weeks we had a predictable explosion of spring weeds –
Of course, that’s not all that easy to do. 
Out on the hills, “what comes” is pretty good right now. 