Can be grown as a shrub or tree. Mature size depends on natural form of plant (most are seed grown and take on very different forms). If you are looking for a uniform group of shrubs/trees, this is NOT the plant to choose. Foliage and form can vary greatly. Some weeping so much that they require staking to keep them growing upright. Others naturally grow upwards. Beautiful tree, loves hot, dry weather and well drained soils.