The 'capillary effect'. See the link.
4.6
To measure the diameter of a capillary tube using a traveling microscope and vernier caliper, place the capillary tube on a flat surface. View the capillary tube through the traveling microscope to measure the external diameter. Then, use the vernier caliper to measure the internal diameter by gently inserting the capillary tube between the jaws of the caliper to get an accurate measurement. Subsequently, calculate the average diameter using the two measurements.
It is because of the surface tension between liquid molecules and the inner surface of the tube. The meniscus height is determined by the inner diameter of the tube. The smaller the diameter, the higher the meniscus will climb due to capillary action.
The height to which water can rise in a capillary tube is calculated using the equation h = 2γcos(θ)/ρgr, where γ is the surface tension of water, θ is the contact angle, ρ is the density of water, g is the acceleration due to gravity, and r is the radius of the tube. For a tube with a diameter of 0.1 mm, the radius would be 0.05 mm. Water typically has a contact angle close to 0, resulting in a high degree of wetting, allowing it to rise several millimeters in a capillary tube of this size.
capillary
due to capillary action
capillary rise
capillary action
Capillary rise in plants helps in the transportation of water from roots to leaves. In insects, capillary action assists in the movement of liquids through small channels like tracheae and tracheoles. In sea sponges, capillary action helps in filtering and absorbing nutrients from water.
the capillaries help you breath
The rise of water in a tall plant also depends on capillary action and transpiration pull. Capillary action helps water move upward through small tubes in the plant's xylem, while transpiration pull helps create a negative pressure gradient that pulls water up from the roots to the leaves.