What is lateral meristem and how does it differ from apical meristem?

Lateral meristem is a type of meristematic tissue located along the sides of stems and roots, responsible for increasing the girth or thickness of plant organs (secondary growth). The two main types are vascular cambium (produces secondary xylem and phloem) and cork cambium (produces protective cork tissue). Unlike apical meristems that enable vertical growth at shoot and root tips, lateral meristems facilitate horizontal expansion. This secondary growth is characteristic of woody plants like trees and shrubs, allowing them to develop thick trunks and branches. Lateral meristems are absent in most monocots, which is why plants like grasses and palms don't undergo significant thickening.