Simplify the following text for a Grade 10 native English-speaking person.
Original: The vascular cambium is the source of both the secondary xylem ( inwards , towards the pith ) and the secondary phloem ( outwards ) , and is located between these tissues in the stem and root .
Simplified: It is the source of both the secondary xylem ( inwards , towards the pith ) and the secondary phloem ( outwards ) , and is between these tissues in the stem and root .