Sensitive stamens

Sparmannia africana (African linden tree)

It is well-known that some plants can move their leaves, such as Sensitive plant (Mimosa pudica) and Venus flytrap. But that some plants can move their stamens, this was new to me.

The stamens of these plants are sensitive to touch, when you lightly brush the flowers with a finger the stamens either move inwards towards the stylus (like in Mahonia) or outwards towards the petals (like in Sparmannia africana, also called African linden tree). This movement is quite quick and easy to see.

Mahonia flowers before touching with stamens near the petals

Mahonia flowers after touching, the stamens have moved inwards

The stamen movement is most likely aiding pollination by bringing the stamens (and with it the pollen) in better contact with visiting pollinators. Other plants with stamen movement are Berberis species, Opuntia and Helianthemum nummularium.

Helianthemum nummularium, another plant with sensitive stamens

 
 Watch this short video to see how it works.