Tex. Code Crim. Proc. art. 38.16
Current with legislation from the 2023 Regular and Special Sessions signed by the Governor as of November 21, 2023.
Evidence shall not be admitted in a prosecution for treason as to an overt act not expressly charged in the indictment; nor shall any person be convicted under an indictment for treason unless one or more overt acts are expressly charged therein.
Tex. Code Crim. Proc. § 38.16