1. (noun) beach spinach, New Zealand spinach, Tetragonia tetragonioides, and climbing New Zealand spinach, Tetragonia implexicoma - similar native plants with round to heart-shaped, alternating, thick, fleshy leaves glistening with a fine powder. Have small, yellow flowers in spring. Creeping plants with stems and leaves often reddish. Found on sand dunes, beach gravel, and rocks.