All appropriations made by the legislature for the support and maintenance of the system universities, for the purchase of land or buildings for the universities, for the erection or repair of buildings, for the purchase of apparatus, libraries, or equipment of any kind, or for any other improvement of any kind shall be disbursed under the direction and authority of the board. The board may formulate rules for the general control and management of the universities, for the auditing and approving of accounts, and for the issuance of vouchers and warrants which are necessary for the efficient administration of the universities.
Tex. Educ. Code § 95.28