For the purposes of this chapter, a weed or plant is considered to be a noxious weed if declared to be a noxious weed by:

1. (1) a law of this state; or
2. (2) the department acting under the authority of Chapter 61 of this code or any other law of this state.

Acts 1981, 67th Leg., p. 1209, ch. 388, Sec. 1, eff. Sept. 1, 1981.