Cal. Bus. & Prof. Code § 26223

(a) Three or more natural persons, who are engaged in the cultivation of any cannabis product, may form an association pursuant to this chapter for the purpose of engaging in any activity in connection with any of the following:
1. (1) The cultivation, marketing, or selling of the cannabis products of its members.
2. (2) The growing, harvesting, curing, drying, trimming, packing, grading, storing, or handling of any product of its members.
3. (3) The manufacturing, selling, or supplying to its members of machinery, equipment, or supplies.
4. (4) The financing of the activities that are specified by this section.
(b) Members of a cannabis cooperative shall be disclosed to the department before the application is processed.
(c) Members of a cannabis cooperative formed pursuant to this chapter shall be limited to cultivators who only hold a single Type 1 or Type 2 license.
(d) Collectively, members of a cannabis cooperative shall not grow more than four acres of total canopy size of cultivation throughout the state during the period that the respective licensees are valid.
(e) No member of a cooperative formed pursuant to this section shall be licensed to operate a cannabis business in another state or country.