Mustard Fields Forever

Mountainside fields of mustard plants brightened our gray day of hiking high in the Sierras near the village of Cuajimoloyas.The people eat the leaves in salads, chopped in scrambled eggs, and undoubtedly many other preparations. Remnants of the plants are fed to the animals, as oxen are commonly used to plow these fields. (goats are common too).
I asked the guide if they use the mustard seeds for seasoning, and he said, "No, for that we have chiles!"  

As for ID of yesterday's plant, it appears to be: 
Family: Apocynaceae, 
Genus: huernia or stapelia   
The closest I could find could be huernia schneiderana
There are so many varieties it is mind-boggling!