Various locations, as described below. A little exploration of Ragworts.
I've been looking at my local Ragwort (Senecio spp.) populations and considering them in the light of various references in books and on the internet. My conclusion is that at least one major (and perhaps two minor) reference books are inaccurate. I suspect that the main feature discussed (the colouring of bracts behind the flower head) cannot be used for identification because:
a) it certainly varies according to location
b) it might vary according to season as well. (monitoring next year will clarify this).
The two main species discussed are Common Ragwort (Senecio jacobaea) and Marsh Ragwort (Senecio aquaticus). Their hybrid, Senecio x ostenfeldii is also discussed.
It should be emphasised that these are my local specimens, and my local analysis. I know that specimens from (at least) Berkshire, the south coast of England, Yorkshire and Skye are different.
Torrential rain.
Common Ragwort (Senecio jacobaea) is very common around here and is routinely destroyed because of its toxic effects on livestock. It is, however, an essential foodplant of some moths and I feel that some populations should be left untouched because of this (and because their location poses no threat to livestock).
A number of points are worth noting. The flower heads are tightly packed together - they overlap. The emerging petals are tightly curled (almost cylindrical). The bracts are very clearly black tipped. There is no large terminal lobe on the leaves. This species grows in fields, hedgerows and on verges.
Marsh Ragwort - Senecio aquatilis - is is much more 'lax' plant. The flower heads are very widely spaced, and the individual petals are more widely separated.
Features are: Whitish edge to the bracts, a large terminal lobe on the leaves, living in or very near water. Emerging petals not curled in a tube.
So far, so good. But I noticed that some 'Marsh Ragworts' were growing in places that did not appear to be particularly damp, and some 'Common Ragworts' were growing in or near water. So I looked a little more closely.
Face-on, the flowers appear to be intermediate between the two previous specimens, and the flower heads are not close, but not widely spaced. The side-view is more confusing, because it appears to show bracts with neither white edges nor black tips. Unfortunately, the leaves on this specimen were long gone, so I'll need to wait and see how the seeds turn out. This was growing at the road-side with no obvious water for 10 metres or so.