Characteristics
Tree species are classified either as gymnosperms,
which generally have needle-like leaves, or as angiosperms, which generally have broad leaves and are deciduous in temperate climates. In practice, trees
usually are classified as softwoods, hardwoods, or tropical woods. Softwoods include the temperate gymnosperms or conifers; hardwoods include the temperate angiosperms; and tropical hardwoods primarily are angiosperms, but also include some gymnosperms that thrive in tropical climates.