Umbilicus rupestris
Known also as Wall Pennywort and Penny-pies. It should be looked for on crevices of rocks and on stone-built hedges along the western coasts of English and Scotland and in Ireland. It extends more sparingly along the south coast as far as Kent.
Flowering from May to August.
The Observer’s Book of Wild Flowers, compiled by W. J. Stokoe (1957)