Poikilohydry
Encyclopedia
Poikilohydry is a condition in organisms that lack a mechanism to prevent desiccation
, such as the lichen
s and bryophytes. The structures supporting poikilohydry are typically small enough to reside in the diffusion boundary layer
, where the cuticle or stomata do not have a sufficient guarding effect on the amount of water lost from the organism. Poikilohydry is also noted in many forms of aquatic algae, which may be able to survive desiccation between successive high tides, or during occasional stranding due to the drying of a lake or pond.
The antonym is Homoiohydry.
Desiccation
Desiccation is the state of extreme dryness, or the process of extreme drying. A desiccant is a hygroscopic substance that induces or sustains such a state in its local vicinity in a moderately sealed container.-Science:...
, such as the lichen
Lichen
Lichens are composite organisms consisting of a symbiotic organism composed of a fungus with a photosynthetic partner , usually either a green alga or cyanobacterium...
s and bryophytes. The structures supporting poikilohydry are typically small enough to reside in the diffusion boundary layer
Diffusion boundary layer
The diffusion boundary layer is a thin layer of fluid which is not mixed with the main body of the fluid , by virtue of its proximity to the fluid's edge. In the case of flora the diffusion boundary layer is often associated with the leaf surface, where stomatal gas exchange occurs...
, where the cuticle or stomata do not have a sufficient guarding effect on the amount of water lost from the organism. Poikilohydry is also noted in many forms of aquatic algae, which may be able to survive desiccation between successive high tides, or during occasional stranding due to the drying of a lake or pond.
The antonym is Homoiohydry.