Q.How does guttation differ from transpiration?

Guttation is loss of liquid water droplets from the leaf margins through hydathodes, driven by root pressure, typically seen in the early morning.

When the soil is very moist and transpiration is low (for example at night or in humid early-morning conditions), root pressure pushes xylem sap upward faster than it can be lost as vapour through the stomata. This excess water is instead exuded in liquid form through hydathodes — small permanent pore-like structures usually located at the tips or margins of leaves, associated with the ends of veins. …

Guttation — the exudation of water droplets from leaf margins — occurs through specialised pores called hydathodes, driven by root pressure.

When the soil is very moist and the air is humid (so transpiration through stomata is minimal, typically at night or early morning), root pressure continues to push water up the xylem. Since transpirational pull is not withdrawing this excess water fast enough through the stomata, it is forced out in liquid form through hydathodes — small permanent pores usually located at the tips or margins of leaves, each connected to the end of a vein. This is different from stomata (option a), which release water vapour during transpiration, and from lenticels (opti …