The differences between hardwoods and softwoods come from the difference in their cellular structure. Softwoods, which come from conifers such as fir, pine and cedar, have a simple cellular structure with 90-95% of the cells being longitudinal tracheids. Longitudinal tracheids are cells that give the tree support and conduct water. The limited and more uniform cell types can make softwoods more difficult to differentiate from one another.
Hardwoods, which come from broad leaf trees, have a more complex cellular structure which varies greatly between species. This tends to create a lot of visible difference between the wood of different hardwood species. Most of the volume in hardwood is from fiber cells that provide structural support for the tree. The main difference between hardwood and softwood is the presence of pores or vessels that exist in hardwood. The main function of the vessels is to transport water throughout the tree.
Is pinon considered to be a softwood? If so, why does it burn as hot as some hardwoods?
As with all pines and needle bearing trees, pinon is a softwood in structure. But it is a slow growing tree with very tight growth rings, which gives it a higher density and hardness than most softwoods, almost like a hardwood, so it burns more similar to hardwoods.