These movements probably occurr so that the leaves provide successful balance between maximal photosynthesis and minimal water loss. Typically leaves are a deep sombre green. The edges of the leaf are entirely or finely serrated, and there is often a long drawn-out end forming a pronounced drip tip. The theory is that quick run-off of water keeps the leaf clean of spores as well as the eggs and larvae of insects, thus helping the leaf to photosynthesise efficiently. The diversity of flowers and fruits is remarkable.
Books are full of photographs of emergent trees in colourful bloom.
This often seems to be associated with plants pollinated by animals living in the lower forest layers and ants and other insects, and even birds and bats which can perch easily on the woody stems.