Pontifications on Poison
Being some ramblings on events associated with poisonous plants.
Wednesday 5th October 2011
I came across a blog written by an Australian dairy farmer. She made an interesting observation about the possible relationship between more intensive farming and improved pasture management.
Her point, in the piece I read is that having more cattle in paddocks that are sub-divided much more than they used to be makes pasture management much easier and she hasn’t seen any Jacobaea vulgaris, common ragwort, in years. Her family has farmed the same land for generations and, with her brother, she remembers spending a lot of time pulling up ragwort. She also says this way of using the land has resulted in a much better quality of sward.
What stirred her memory of her childhood ragwort pulling, provoking her comment and leading me to write today’s post was her daughter pulling up her first ever Patterson’s Curse, Echium plantagineum, plant. You can sense a mother's pride that her 5-year old daughter is already starting to learn her way around the land and understanding the different flora and fauna it supports.
The Patterson of Patterson’s curse is Jane Patterson (sometimes written Paterson) who is believed to have brought seeds of the plant to Australia in the 1880s to grow in her garden. As so often happens in such stories, the plant escaped Jane’s garden and found the Australian environment reasonably conducive to its spread. In fact, it doesn’t compete that well with established native plants but if ground is disturbed or over-grazed it will out compete native plants trying to re-establish themselves.
It is another plant, like ragwort, that contains pyrrolizidine alkaloids (PAs) and can cause death from liver failure in grazing animals. Various methods are used to try and control it from hand-pulling for small populations to spraying. After careful research, a number of biological controls have been introduced from the plant’s Mediterranean home in the hope that they will provide a long-term control system.
This could well happen because Fallopia japonica, Japanese knotweed, which is a serious problem in the UK does not cause difficulties in its native Japan where there are natural controls on it. If the right bugs have been selected and if they don’t do something not seen in the research and trials, then biological control of Echium plantagineum may be effective.
In the UK, the species of the Echium genus most commonly found is Echium vulgare, viper’s bugloss. ‘Bugloss’ is taken from the Greek for ox-tongue and was given to the Anchusa genus of plants whose leaves are said by some to look like the ox’s tongue though other sources say it is the roughness of the leaves having the feel of an ox’s tongue that brought about the name. In giving the name ‘viper’s bugloss’ to Echium vulgare, the ‘ox’ has, in effect been dropped and the name means the leaves look or feel like a snake’s tongue.
In addition, the seeds are said to look like a snake’s head and some people say the stalks look like snakeskin. All of which leads to the plant being a good example of the Doctrine of Signatures because since, at least, Dioscorides’ time it has been recommended both for the treatment of snakebites and to keep snakes and serpents away.
Turner says that it is, in some places, known as ‘cats’ tail’ but gives no explanation for this name. I might guess that the name refers to the very long taproot that the plant puts down that makes it difficult to pull up and, in the Australian context, gives it a better chance of doing well in severe drought than other plants.
This ability to survive adverse conditions is referred to on the plant page in connection with its rapid recovery after bushfires in the Canberra area in 2003. A reported 40 horses were put down after becoming ill from having only Echium plantagineum on which to graze.