Alyssum saxatilis now Aurinia saxatilis

Lovely bright golden yellow flowers smother this compact mound of grey-green leaves, will spill down a wall or bank from mid spring until frosts. Hardy and easy, but I have found it to be not so long lived on occasions, but prop cuttings into sand to preserve and share. Trim to maintain shape in winter. Rock garden trough, sand and gravel gardens.  Full sun. up to 60cmW 30cm H so three times larger than the species. 

www.gardenerspath.com has some great information on this and many other plants,  and a wonderful image 

the images are of my plants. While the colour difference is easy to see, the phone won't differentiate. But it is a lovely warm yellow. A creamy brighter lemon-yellow version is available too.