The invasive ragwort.
NATURE NOTESAT THIS time of the year many passions are aroused by the appearance of a number of invasive species of plants.
This year, in particular, the volume of ragwort has prompted several letters to the paper and expressions of concern over its dangers to livestock.
Arguments abound over how the plant should be controlled and it has traditionally been hand pulled where it occurs in pasture.
However, it must be removed from the site because it remains toxic even when dry and therefore can be fatal if included in hay.
Control methods nowadays include topping (cutting while in flower but before setting seed) and spot-spraying (brushing or spraying individual plants). Both of these techniques are also used for thistles, another pasture-invading plant.
It is debatable whether any of these methods are successful and even more debatable whether they are cost effective. However, it is not illegal to have ragwort on your land (although it is an offence to allow it to spread onto land owned by others) and it is an important food plant for certain species of moths. Large swathes of it can also look rather attractive, if you like the strident yellow flowers.
Other plants make their presence felt at this time, including some which are non-native. Most have been introduced as garden plants at some point — some by the Victorians and others more recently.
Giant hogweed is an architecturally striking plant, related to our own native hogweed but considerably larger (often over 10ft high).
It has the unfortunate property of rendering human skin very sensitive to sunlight, resulting in nasty blisters if you should inadvertently touch it; the stem in particular.
It has a fondness for damp shady places and often grows along river banks or on pond sides, where it can look spectacular.
Various members of the polygonum family of plants have made themselves felt in the last 30 years or so. Japanese and giant knotweed grace our hedges with huge heart-shaped leaves and tiny white flowers, while Russian Vine drapes everything it can find with curtains of equally tiny white flowers.
Both were originally imported as garden plants but they can now be found in hedgerows all over the country.
As with ragwort, there are arguments about whether or not it is necessary or worth trying to control invasive plants in general.
Many invasive species are entirely native and cause just as much of a problem as introduced species.
Bracken can take over in moorland areas and vast sums of money have been spent in some places trying to control it with aerial spraying.
In the past, bracken was used for animal bedding, but now its reputation as a carcinogenic (cancer-causing) agent has made it persona non grata.
Brambles and nettles can rapidly make some areas inaccessible to humans but provide much benefit to wildlife as food sources and valuable cover.
And then there is the seaweed. Build-up of seaweed in the summer can be a serious deterrent to spending time on the beach in some places but, again, it used to be considered to be a valuable commodity: collected up and spread on the land as fertiliser.
So, should we be trying to play Canute with these plants or should we be a little more tolerant?
Perhaps we should be taking a broader view and looking at the benefits they offer, including the visual ones, rather than concentrating on the drawbacks.
We do, after all, make room in our gardens for lots of plants which are poisonous and admire many native wild plants which are equally toxic. Answers on a postcard please.