from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. Growth or movement of a sessile organism toward or away from a source of light.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. the movement of a plant towards or away from light

from the GNU version of the Collaborative International Dictionary of English

  • n. The tendency of growing plant organs to move or curve under the influence of light. In ordinary use the term is practically synonymous with heliotropism.
  • n. exhibiting movement in a direction toward (positive phototropism) or away from (negative phototropism) a source of light.

from The Century Dictionary and Cyclopedia

  • n. The growth or the bending of organisms or of parts of organisms in relation to light; heliotropism.
  • n. Same as phototaxis, 2.
  • n. Same as phototropy, 2.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. an orienting response to light


Sorry, no etymologies found.


  • Maybe there's some phototropism in there as well they seem to be moving to the shadow at the top?

    Clustering of the intertidal snail Batillaria minima

  • Make sure you look at the movies for morning glories twining, and corn seedling phototropism.

    Rambles at » Blog Archive » Green machines

  • Thus it was that the interpretations of J. Loeb (Die Tropismen, 1913) on the basis of experiments done with lower animals, estab - lished the neologist ideas of “phototropism” (orien - tation or displacement reaction in the direction of light), and of “thermotropism” (reaction directed to - wards a source of heat), to explain animal and perhaps also human behavior.

    Dictionary of the History of Ideas

  • Where the specific stimulus is light, the phenomenon is phototropism ( "light-turning" G).

    The Human Brain

  • Almost 200 years ago, researchers first began to characterize plant responses to sunlight-among them, the propensity of a plant's tip to grow towards the light and its root to grow away from the light, a phenomenon called phototropism.

    News from The Scientist

  • Winslow Briggs has been fascinated by phototropism for more than 50 years, chipping away at the mechanism behind it in his lab at Carnegie Institution's Department of Plant Biology at Stanford University.

    News from The Scientist

  • Since then, the study of phototropism has been a cornerstone of plant science research.

    News from The Scientist

  • They took photos to document phototropism in plants - how plants grow in the direction of the sun - and erosion.


  • It's not a phototropism, but a "sun" tropism following the position of the sun.

    Israelated - English Israel blogs

  • Action abscisic acid auxin transport relationship phototropism



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