epinasty

American  

[ep-uh-nas-tee] / ˈɛp əˌnæs ti /

noun

Botany.

1. (especially of leaves) increased growth on the upper surface of an organ or part, causing it to bend downward.

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epinasty British  

/ ˈɛpɪˌnæstɪ /

noun

1. increased growth of the upper surface of a plant part, such as a leaf, resulting in a downward bending of the part Compare hyponasty

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Other Word Forms

• epinastic
  adjective

Etymology

Origin of epinasty

1875–80; epi- + Greek nast ( ós ) pressed close + -y ³

Example Sentences

See Examples For:

epinasty

On the other hand, from observing the effects of tying a shoot downwards, so that the rectangle faced upwards, we are led to believe that the curvature is partly due to epinasty.

From The Power of Movement in Plants by Charles Darwin

These changes of position, which are due to epinasty or hyponasty, occur at certain periods of the life of the plant, and are independent of any external agency.

From The Power of Movement in Plants by Charles Darwin

The young leaves of Cannabis sativa sink at night between 30o and 40o beneath the horizon; and Kraus attributes this to epinasty in conjunction with the absorption of water.

From The Power of Movement in Plants by Charles Darwin

Therefore this case seems very different from that of ordinary sleep, and probably comes under the head of epinasty, as is the case with the leaves of this plant according to Kraus.

From The Power of Movement in Plants by Charles Darwin

De Vries has shown* that the more or less horizontal position of leaves is in most cases influenced by epinasty, by their own weight, and by apogeotropism.

From The Power of Movement in Plants by Charles Darwin