Delosperma nubigenum (Yellow Hardy Ice Plant)
Delosperma nubigenum growing on a flat roof with next to no soil. This is one tough plant that takes on a red hue in winter and scores of yellow daisy like flowers in summer.
More commonly known as the Hardy Ice Plant it grows to provide a dense mat. I have found it does well in pots due to its drought resistance. If you do grow this in a pot it can be located in both full sun or shade. It will look great with the plant spilling over the edges giving a lush dripping foliage effect.
You may also find the Delosperma 'Jewel of Desert' series of interest, developed from nubigenum offering more flower colour variations.