Sedum acre is a hardy perennial succulent that grows as a dense mat-like ground cover, spreading by creeping stems that take root where they touch the ground.
It often grows in cracks in pavers or even on walls.
It's a dense mat forming plant that resembles moss and in spring it produces masses of yellow flower heads that almost cover the foliage completely.
An easy plant to grow and maintain that can fill awkward locations - especially rocky or uneven surfaces.