Ultimately the crown broadens, and this can happen in different ways. Some radial limbs thicken and
lengthen so that a broad but still monopodial crown develops, and this is sometimes trapezoid in outline.
Eventually a truly sympodial structure may develop.The crown branches are sometimes almost as massive
as the trunk. The clear bole height and crown depth also vary. Some species have a distinct tendency to
develop several trunks. The degree to which this happens, and also the degree of self-pruning and the stage of development and massiveness of the mature crown, can be seen to vary somewhat with environment.