Cal. Corporations Code § 16912

(a) Unless a future effective date or time is provided in a certificate of merger if a certificate of merger is required to be filed under Section 16915 in which event the merger shall be effective at the future effective date or time: (1) A merger in which no domestic other business entity is a party to the merger shall be effective upon the later of any of the following: (A) The approval of the agreement of merger by all parties to the merger as provided in Section 16911. (B) The filing of all documents required by law to be filed as a condition to the effectiveness of the merger; or (C) Any effective date specified in the agreement of merger; and (2) A merger in which a domestic other business entity is a party to the merger shall be effective upon the filing of the certificate of merger in the office of the Secretary of State. (b) For all mergers in which a certificate of merger is required to be filed under Section 16915, a copy of the certificate of merger duly certified by the Secretary of State is conclusive evidence of the merger of (A) the constituent partnerships (either by themselves or together with constituent other business entities) into the surviving other business entity, or (B) the constituent partnerships or the constituent other business entities, or both, into the surviving partnership.