In message , Emrys Davies
writes
This plant is a perennial in full flower with pure white daisy like
flowers, 2" across, with a bulbous yellow centre. They are borne on 9"
stems. The main foliage is quite dense, very low growing, about 4-5",
is a pleasing green/grey and has a spread of 18". It is quite similar to
carrot leaves, only much shorter, about 2". It appears to root as it
goes.


Try Rhodanthemum hosmariense (aka Chrysanthemopsis hosmariensis). Most
of the other daisies with flowers matching that description (e.g.
Leucanthemum, Matricaria) are later flowering.
--
Stewart Robert Hinsley