A geranium flowering prolifically in the ‘fernery’ might be Geranium Macrorrhizum ‘Bevan’s Variety’ by Woottens of Wenhaston. It was only rated 7/10 by Michael Loftus, the founder of the nursery, and I suspect the reason is its slightly untidy growth and lack of strong markings on the petals. But I find it a generous plant and much loved by the bees. I am growing it is pots and in the garden. However, its provenance remains to be confirmed…

don’t you just love them !!! I have loads of them in my garden, it’s an ideal plant for every place !!!
Yes, hugely rewarding plants and very generous in spreading themselves!
they spread themselves generously but they are removed easily unlike others ! and I love to give plants away…
True on both counts!