2 U.S. Code § 2142
2 U.S. Code § 2141 is about Superintendent of Botanic Garden and greenhouses. It is under Subchapter VI (Botanic Garden and National Garden) of Chapter 30 (Operation and Maintenance of Capitol Complex) of Title 2 (The Congress) of the Code.
There shall be a superintendent and assistants in the Botanical Garden and greenhouses, who shall be under the direction of the Joint Committee on the Library.