DENDROLOGY

Detailed explanation-1: -The bark of the tree comprises all the tissues outside the vascular cambium. Various kinds of cell layers that constitute the bark are – Periderm (phellogen, phellem and phelloderm), primary cortex, pericycle, primary and secondary phloem. These all tissues are present outside the vascular cambium.

Detailed explanation-2: -B: The inner bark, or “phloem”, is pipeline through which food is passed to the rest of the tree. It lives for only a short time, then dies and turns to cork to become part of the protective outer bark.

Detailed explanation-3: -The inner soft bark, or bast, is produced by the vascular cambium; it consists of secondary phloem tissue whose innermost layer conveys food from the leaves to the rest of the plant. The outer bark, which is mostly dead tissue, is the product of the cork cambium (phellogen).

Detailed explanation-4: -Rhytidome. The rhytidome is the most familiar part of bark, being the outer layer that covers the trunks of trees. It is composed mostly of dead cells and is produced by the formation of multiple layers of suberized periderm, cortical and phloem tissue.