I want to know the answer to the following question:
Besides ring-porous, what's the other class hardwoods are often divided into?
All the background I'm provided with is that "The water conducting capability is mostly taken care of by vessels: in some cases (oak, chestnut, ash) these are quite large and distinct, in others (buckeye, poplar, willow) too small to be seen without a hand lens.". Is that enough to answer the question?