These were either forgotten or were torn up and replaced by cement aqueducts in the early 1960's. Which ever or both are very likely to be true. All of the cane I found is growing either on small ranches or in washes of the San Fernando Valley. The root is mainly a soil adjusted organ. The stems have two main functions, they support the leaves in the air and light where they can carry on photosynthesis.
Stems act as channels through which water and solules reach the leaves.
Many perennials store food in their roots or stems to carry them through the winter and to start their growth the following spring. Sod is a combination of branching rhizomes and numerous adventitious fibrous roots growing from them. This rhizome phenomenon is one of the striking characteristics of Arundo donax. This explains the relative shallow root system and the difficulty of removing a plant from the ground without destroying it. The rhizomes or the underground stems are the cause of the difficulty of removal by their locking the plant into the ground.