Phloem
Explanation:
Xylem and phloem are conducting tissues of plants,. The xylem conducts water from roots to various part of the shoot and phloem conducts food from leaves to other parts of the plant.
The cork cambium in the stem forms xylem towards the centre and phloem towards the periphery. When we pull off the bark of the tree we pull off tissue from the periphery. So we can say that we are observing phloem when we pull off a small piece of bark.