In the tropical rainforest most trees in the rainforest have wide buttress roots. This is to support them as they grow incredibly tall (over 200ft in some cases) as there is great competition for sunlight. Lianas (vines) grow around trees as they bid to reach sunlight. The leaves of many trees are waxy and have drip tips to allow water to run off them (so that water does not gather on leaves and cause them to rot, it also allows water to reach the roots on the forest floor). Leaf stems are also flexible to allow leaves to move with the sun to maximise photosynthesis.