Abstract: An upright standard of non-circular cross section is provided and includes a lower end for anchoring in the ground and an upper end portion including first and second oppositely facing sides. One of the sides is substantially straight longitudinally of the standard and the other side includes a plurality of abutments spaced therealong and projecting outwardly therefrom. A horizontal support arm is provided and includes base and free ends and the base end defines an upstanding opening formed therethrough. The upper end of the standard is slidingly received through the opening with the free arm end projecting laterally outwardly from the straight standard side. The base end of the arm includes an abutment surface spaced below the opening and toward the base end from the side of the opening adjacent the free arm end and abuttingly engageable with the standard straight side one surface.