Which structure would be most beneficial for a plant in a tundra biome?

A small leaf structure is a physical adaptation that helps plants survive. Plants lose water through their leaf surface. By producing small leaves the plant is more able to retain the moisture it has stored.  Growing close together and low to the ground are also some of the adaptations that plants use to survive.  Only plants with shallow root systems grow in the Arctic tundra because the permafrost prevents plants from sending their roots down past the active layer of soil.