I thought I'd make the photo extra large as this is quite a small but incredibly common plant. It's one of the pavement plants, part of the footpath flora we walk past every day. Senecio vulgaris is one of the ragwort crowd and a member of the daisy family, Asteraceae. The key identification feature is the black tips of the short outer bracts and (less obvious) long inner bracts. It is an annual so must be declared something of a winner given its ubiquity, despite invariably attracting the epithet "weed".