Xerophytes
Xerophytes
A xerophyte is a plant which has adaptations which allows it to live in an environment with little available moisture (the opposite being a hydrophyte). There are some adaptations that are typical of xerophytes, usually to reduce the rate of transpiration:
A thick waxy cuticle: By having this, the plant can limit the amount of water lost through evaporation. If there is little available; why lose what you have? Its shiny surface is also reflective with regards to light, keeping the leaf cool. For example, Lithops live in the deserts of South Africa, Namibia and Botswana.
Sunken stomata: By sinking the stomata deeper into the epidermis, the plant can retain a moist atmosphere there by being partially covered by the cuticle and hairs called trichomes. They prevent dry air evaporating more water than necessary. The adaptation also allows the plant to keep its stomata open for longer and take in more CO₂.
Leaf rolled with stomata inside: The sandy, salty and windy conditions that marram grass grows in (sand dunes by the sea!) means an increased loss of water through transpiration. To attempt to reduce the loss of water in this way, the leaf is rolled in on itself and has the stomata protected inside; the reduction in air movement reduces transpiration.
Small leaves: By having smaller leaves (often with a circular cross-section), plants have reduced the surface area from which water can evaporate. A familiar example of this is cacti which after living in the desert, have developed leaves that are spines. These not only reduce water loss, but an effective deterrent to animals who want some of the water from the stem of the plant.
Extensive shallow root system: These are typically circular in shape and it allows the plant to take up water very quickly when it rains. This is especially good for plants in rainforests where it rains heavily, but the soil does not retain the water for very long. Species of grass also share these
A xerophyte is a plant which has adaptations which allows it to live in an environment with little available moisture (the opposite being a hydrophyte). There are some adaptations that are typical of xerophytes, usually to reduce the rate of transpiration:
A thick waxy cuticle: By having this, the plant can limit the amount of water lost through evaporation. If there is little available; why lose what you have? Its shiny surface is also reflective with regards to light, keeping the leaf cool. For example, Lithops live in the deserts of South Africa, Namibia and Botswana.
Sunken stomata: By sinking the stomata deeper into the epidermis, the plant can retain a moist atmosphere there by being partially covered by the cuticle and hairs called trichomes. They prevent dry air evaporating more water than necessary. The adaptation also allows the plant to keep its stomata open for longer and take in more CO₂.
Leaf rolled with stomata inside: The sandy, salty and windy conditions that marram grass grows in (sand dunes by the sea!) means an increased loss of water through transpiration. To attempt to reduce the loss of water in this way, the leaf is rolled in on itself and has the stomata protected inside; the reduction in air movement reduces transpiration.
Small leaves: By having smaller leaves (often with a circular cross-section), plants have reduced the surface area from which water can evaporate. A familiar example of this is cacti which after living in the desert, have developed leaves that are spines. These not only reduce water loss, but an effective deterrent to animals who want some of the water from the stem of the plant.
Extensive shallow root system: These are typically circular in shape and it allows the plant to take up water very quickly when it rains. This is especially good for plants in rainforests where it rains heavily, but the soil does not retain the water for very long. Species of grass also share these