heliotropism

American  

[hee-lee-o-truh-piz-uhm, hee-lee-uh-troh-piz-uhm] / ˌhi liˈɒ trəˌpɪz əm, ˌhi li əˈtroʊ pɪz əm /

noun

1. heliotropic tendency or growth.

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heliotropism British  

/ ˌhiːlɪəʊˈtrɒpɪk, ˌhiːlɪˈɒtrəˌpɪzəm /

noun

1. the growth of plants or plant parts (esp flowers) in response to the stimulus of sunlight, so that they turn to face the sun

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heliotropism Scientific  

/ hē′lē-ŏt′rə-pĭz′əm /

1. The growth or movement of a fixed organism, especially a plant, toward or away from sunlight. Heliotropism can be easily seen in sunflowers, which slowly turn their large flowers so that they continually face the sun.

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Other Word Forms

• heliotropic adjective
• heliotropically adverb

Etymology

Origin of heliotropism

First recorded in 1850–55; helio- + -tropism

Example Sentences

The researchers have not yet identified the genes involved in heliotropism.

From Science Daily • Oct. 31, 2023

Blocking blue, ultraviolet, red or far-red light with shade boxes had no effect on the heliotropism response.

From Science Daily • Oct. 31, 2023

Moreover we know from experiments on heliotropism, thermotropism, etc., that even intangible stimuli such as rays of light, etc., impinging unsymmetrically on these delicate cells cause alterations in their behaviour—e.g. arrest or acceleration of growth.

From Disease in Plants by Ward, H. Marshall

We may briefly discuss the question of the transmission through the sex cells of such instincts as are based upon heliotropism.

From Darwin and Modern Science by Seward, A. C. (Albert Charles)

In both sets of cases the movement may be modified in a closely analogous manner by geotropism and by heliotropism; though few climbing plants are heliotropic.

From The Power of Movement in Plants by Darwin, Charles