State the functions of the following:
Hydathodes:
Topic: Hydathodes
Try it
Pick an option and check your answer. The full worked answer is below either way.
Answer
(d) Guttation.
HYDATHODES are permanently open pores at the tips and margins of leaves, at the endings of the veins, through which GUTTATION occurs — the loss of water as visible LIQUID DROPS.
WHEN IT HAPPENS: at night or early morning, when the air is humid and the stomata are shut so transpiration cannot occur, but ROOT PRESSURE continues to push water upward. The water is forced out through the hydathodes as droplets along the leaf edge.
OPTION (a) IS THE TRAP, because both are losses of water from the leaf. The distinction is the FORM and the PORE: TRANSPIRATION — water VAPOUR, through STOMATA GUTTATION — water DROPS, through HYDATHODES
The droplets on grass early in the morning may be either guttation or dew — dew condenses from the air, guttation comes from inside the plant.
Guttation.