Final answer:
Intercalary meristems in grasses provide modular growth after damage, allowing grasses to produce new tillers from lower nodes, facilitating rapid regrowth and replacement of lost tissue.
Step-by-step explanation:
The intercalary meristems in grasses provide a form of modular growth, as the grass typically will produce branches or tillers from lower nodes when the upper intercalary meristems are damaged or removed through the actions of grazing by herbivores or mechanical harvest. Intercalary meristems are specialized areas of growth in monocots, specifically present at the base of leaf blades and at nodes, which enable the grass leaves to elongate from the base after being cut or grazed. This adaptive strategy allows grasses to rapidly resume growth and replace lost photosynthetic tissue, ensuring survival and continual growth after being grazed or mowed — key to the success of grasses as a group.
Grass plants often utilize their branching abilities as a response to environmental interactions. When the apical dominance is removed by cutting at the intercalary meristem, other dormant growth centers like the branch primordia at the lowest leaves are stimulated, resulting in the production of tillers, stolons, or rhizomes. These structures can extend either vertically to create a new leafy stem akin to the original (called a tiller in grasses), or horizontally either above ground as stolons or below ground as rhizomes. Both stolons and rhizomes may eventually lead to producing vertical, photosynthetic stems from bud primordia associated with the rudimentary leaves they bear.