Hottentot Fig, Highway Ice Plant.
Formerly known as: Mesembryanthemum edulis.
This is an invader from South Africa, initially planted around railway lines to control erosion, later planted by CalTrans for the same purpose on highways.
It generally is found near the coast, and at low elevations.
It looks very similar to its cousin C. chilensis except this species has a larger yellow flower, and, in general, is a larger plant.
The stringy petal-like things around the flower are not true petals but sterile stamens (staminoides).
Both the triangular leaves, and the fruits are edible.
The flowers close in the night and reopen again in the late morning.