Smoke from burning poison ivy can also affect your skin. People vary so much in their susceptibility to poison ivy that it is not a problem for some, while it can be serious for those who are highly allergic, often requiring medication and medical care. It is easy to learn to recognize poison ivy in summer by the three leaves and in winter by the white berries. Bark is the protective coat of the tree. Board Foot is a way of measuring timber and lumber.
Cambium is the growing part of the tree trunk.
It is the layer under the inner bark. Conifers are trees that bear their seeds in cones, and have slender, pointed, needle-like leaves. Most conifers do not lose all of their leaves at one time, but drop them gradually over a period of 1 or more years. The leaves remain green all year. This is why they are called evergreens.