Plasticity

Plasticity is the capacity of a plant to be moulded or modelled -- its ability to produce different kinds of structures in response to different external (environmental) or internal stimuli at different phases of its life, rather than always producing one fixed form. A commonly cited example is heterophylly, where the same plant produces leaves of different shapes at its juvenile and mature stages, or under different environmental conditions -- seen in cotton, coriander and larkspur (Delphinium). In Ranunculus flabellaris (buttercup), heterophylly is triggered by the surrounding environment -- the plant produces finely divided leaves when submerged in water and broader leaves in air -- so this is called environmental heterophylly. In coriander and cotton, by contrast, the change in leaf form is governed more by the plant's own developmental (intrinsic) programme as it moves from the juvenile to the adult stage, independent of a specific external trigger, and this is called intrinsic plasticity.