53 Pa. Stat. § 3291
In townships of the first class, boroughs, and cities of the commonwealth of Pennsylvania there may be appointed, in the manner hereinafter provided, a commission of three freeholders, to be known and designated as the shade-tree commission of the said township, borough, or city, who shall serve without compensation, and who shall have exclusive and absolute custody and control of, and power to plant, set out, remove, maintain, protect, and care for, shade-trees, on any of the public highways of the said townships, boroughs, and cities, the cost thereof to be provided for in the manner hereinafter stated: Provided, That in townships, boroughs, or cities in which a commission for the care of public parks shall have been created, said commission shall, upon the acceptance of this act as provided in section two, be charged with the duties of the commission as above provided, and shall, for that purpose, be possessed of all the powers herein mentioned and granted.
53 P.S. § 3291