Pontifications on Poison
Being some ramblings on events associated with poisonous plants.
Monday 5th September 2011
I’ve mentioned my new camera before. Like a lot of the latest generation of digital cameras it is capable of taking high-definition video as well as still. I use video in the presentations that accompany my talks because, I think, it gives the audience something to look at while I’m talking and, hopefully, helps to stop their attention wandering.
As I checked before giving last week’s talk, I realised that the video taken on my previous, standard definition, video camera doesn’t look as good as video taken this summer. I haven’t really been focussed on getting new video through the summer but I managed to get quite a few new clips in order to update the footage I use.
One plant where the standard quality is somewhat lacking is Oenanthe crocata, hemlock water dropwort. That’s partly because the only plant I’ve seen growing in the wild was growing in the shallow water at the edge of a fast-flowing river and the flow made it hard for the camera to get the best image it was capable of.
So, this morning, with it being rather brighter but with no-one else wanting to go out walking, I thought I would see if the plant was still where I had seen it and, if so, whether I could get some high definition footage.
It took me about twenty-five minutes to walk from the road bridge where I left the car to the spot where I had seen the plant. It’s, probably, about a fifteen minute walk in good conditions but the recent rains had left the ground very claggy and slippery and, with carrying my camera and my small tripod, I’d left my walking pole behind. But, fortunately, I reached my destination without sliding off my feet though some of the gradients the path takes were interesting.
Unfortunately, the rain that has made it pretty hard to get out throughout this summer had, at one point, been strong enough to put the river into spate and the Oenanthe crocata had been knocked over as the river rose what looked to have been several feet above its normal level. There was no point in trying to get any video but I did take a few stills and I’m showing them here so you can see that the stems might easily be mistaken for fennel or some other edible plant and also that it has already begun the process of re-growing to replace the knocked over stalks.
Oenanthe crocata is one of the plants where people have mistaken it for its edible lookalikes and not lived to tell the tale. In fact, death can come quite quickly and without any symptoms of poisoning showing themselves so, historically, they could easily be people who ‘just dropped dead’ and no-one realised they had been poisoned.
The other plant pictured on this page is Impatiens glandulifera, Himalayan balsam. It is one of the non-native invasive plants. Unlike Heracleum mantegazzianum, giant hogweed, it doesn’t do physical harm to people and unlike Fallopia japonica, Japanese knotweed, it does not break through tarmac and brickwork but it is still problematic. It is an annual and will out compete native plants. This can mean that when it dies back in the winter it leaves bare ground and that may lead to soil erosion.
It’s most stunning attribute is the way it fires its seeds up to 7m from the parent if it is touched at the right time. This can produce quite a surprise for anyone who does not recognise the plant and know about this property. It’s not poisonous but I thought I’d show a couple of pictures so that you might identify it when out walking.