Xerophytic adaptations of plants

https://www.youtube.com/watch?v=yTzjOzPDKXs

What adaptations do xerophytic plants have to reduce water loss

Thick waxy cuticle - to reduce evaporation

Reduced leaf area - e.g needs reduces sa:v ratio

Hairy leaves- the hairs trap a layer of saturated air

Sunken stomata- the pits above the stomata become saturated

Rollen leaves- this reduces the area exposed to the air and keeps the stomata on the inside so increasing water vapour inside the roll

Succulents- store water in specialised tissues in their stems and roots

Leaf loss- some plants prevent water loss by losing their leaves when water is not available.

Explain the cross section of maram grass leaf

Leaf is rolled with sunken stomata on the inside

Hairs trap water vapour

Water evaporating via the stomata collects in the air trapped in the rolled leaf

This reduces the water potential gradient so reduces water loss from the plant

What are hydrophytes

Plants adapted to wet habitat

Water logging is a major problem for all hydrophytes.

The air spaces need to be full of air, not water. This will help the plants float so they are near the surface so they can get more light for photosynthesis

Adaptations of hydrophytes

Very thin or no waxy cuticle

Floating leaves have stomata on upper surface - in contact with the air, many are always open

Some hydrophytes have air spaces which enable leaves to float to the surface

No supporting structures as water supports the leaves

Smaller roots as there is less need for uptake by roots