I have found a few of these in my garden. They vary in location, from ground to hanging baskets, and don't seem to be near any full grown plants that look anything like them. They are single plants, not in groups. The leaves remind me of rabbit ears in shape, and are soft like velvet but not what I would class as hairy/furry. I don't remember ever planting anything similar, and no seeds have been planted in these places so I am completely clueless! Please can someone enlighten me? Thanks
Well, it could be a lot of things, but what immediately comes to mind is Laphangium luteoalbum. You'll have to wait an see how it develops to see if it matches that ID. If it is, it's not something particularly welcome in a garden.
Might be Silene coronaria (syn. Lychnis coronaria), perhaps? A popular garden plant, fairly often re-seeds.