A small succulent plant rescued from a crack of a walkway not far from a forest in Santa Cruz, California. It must be very hardy to be able to survive in the wild in a crack with little soil and water under the burning sun of California. It's also possible that it was escaped from a garden nearby, I'm not sure. It's about 6 inch (12 cm) in height. The stem feels woody. Please help to identify it's name. Thanks in advance!