Hydrotropism is the growth response to water.
Tropism is a growth response in all or part of a plant due to an external stimulus. Hydrotropism in particular is in response to water (hydro-) and may be further divided as negative or positive hydrotropism.
Negative hydrotropism will cause the plant to move away from moisture, while positive hydrotropism – the most common form – will cause the plant to move towards moisture.
Hydrotropism is valuable in helping plants seek out wetter soils in areas where the soil is too dry (positive hydrotropism,) or avoiding soil that is too wet for the roots (negative hydrotropism.)« Back to Glossary Index