Constitution of the State of Texas 1876 Art. 16, § 11. Usury;  rate of interest in absence of legislation

The Legislature shall have authority to define interest and fix maximum rates of interest;  provided, however, in the absence of legislation fixing maximum rates of interest all contracts for a greater rate of interest than ten per centum (10%) per annum shall be deemed usurious;  provided, further, that in contracts where no rate of interest is agreed upon, the rate shall not exceed six per centum (6%) per annum.