www.ukbutterflies.co.uk

Anyone know what this plant is? I found several clusters of it last week on field/garden edges in SW France, and since then a patch back here in Somerset. The French examples were twice my height and were incredibly attractive to Silver-spotted Skippers, giving the unsettling experience of looking upwards at them as though they were hairstreaks. Also various clouded yellows and Queen of Spain Fritillary. Is it worth growing for butterflies in this country?

Sawtooth sunflower, Helianthus grosseserratuscan, can grow to that kind of height, Chris, although I believe it is native to North America rather than Europe.

https://en.wikipedia.org/wiki/Helianthus_grosseserratus

Could be a garden escape that has gone wild?

Thanks David, that looks a likely ID. Wherever I've seen it - both France and England - it's been in blocks, so the planting looks intentional. I have the seeds from the plants down the lane from me so may just give it a try, though will be doing well to get any of the species mentioned in the original post here (Clouded Yellow turns up here once or twice a decade). Maybe it will join the Asclepias I have been growing this year in a North American pollinator border...