Definition and Classification of plant adaptations: Any feature of an organism or its part which enables it to exist under conditions of its habitat is termed adaptation.
Adaptations or for withstanding adverse conditions of the environment and to utilize the maximum benefit of the environment (nutrition or conditions).
Classification of plant adaptations
Warming (1895) had realized for the first time the influence of controlling or limiting factors upon the vegetation in ecology. He classified plants into several ecological groups on the basis of their requirements of water and also on the basis of the nature of substratum on which they grow.
Warming classified plants on the basis of the nature of substratum (soil) into the following groups.
- Plants of acidic soil (Oxylophytes)
- Plants of saline soil (Halophytes)
- Plants growing on the sand (Psammophytes)
- Plants gaming on the surface of rocks (Lithophytes)
- Plants growing in the crevices of rocks (Chasmophytcs).
Epiphytes are not included in the above classification because of the fact that they do not have a permanent connection with the soil. Warming’s second classification (1909) of the plants is based on their water relations.
On the basis of their water requirement and nature of soils, plants have been classified as follows:
1. Hydrophytes
Plants growing in or near water. (Greek, Hudor means water and Phyton means Plant: water plant). Plants that grow in wet places or in water either partly or wholly submerged are called hydrophytes or aquatic plants.
2. Xerophytes
Plants adapted to survive under the condition of a very poor supply of available water in the habitats. Xerophilous plants are further classified on the basis of their habitats as follows:
- Oxylophytes (on acid soils)
- Halophytes (on saline soils)
- Lithophytes (on rocks)
- Psammophytes (on sand and gravels)
- Chersophytes (on wasteland)
- Eremophytes (on deserts and steppes)
- Psychrophytes (on cold soils)
- Psilophytes (savannah)
- Sclerophytes (Forest and bushland)
3. Mesophytes
Plants growing in an environment that is neither very dry nor very wet. The detailed description of only some important ecological groups is given here.
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