This grower is sure of this plant identification.
Hardy evergreen perennial
Form: Low spreading cushion of soft feathery leaves
Leaf colour: Silver-grey
Flower: Yellow buttons on taller wiry stems in late spring to mid-summer Plant size: Height, 5-10cm Width, 25-30cm
Needs: Well-drained sandy or loam soil in full sun
Suitable for: Rock gardens, gravel screes, troughs and containers
Cotula genus (Brass buttons). This genus consists of perennials and annuals. A few are marginal water plants most of which are evergreen. There are about 80 species. The leaves are small, soft and they are often deeply dissected. The flower heads are small and round.
They are fully to frost hardy and will need a sunny and well drained soil that is not too dry. Dead-head to prolong flowering.
Grown for their neat foliage and button-like flower heads.