Bot. the condition in which an organ, as a leaf, turns upward because of the more rapid growth of the bottom layers of cells
Origin of hyponastyfrom hypo- + -nasty
The upward bending of a leaf or other plant part, resulting from greater growth of the lower side than of the upper side.
- (botany) an upward bending of leaves or other plant parts, caused by increased growth on their lower surface
hypo- + -nasty