|Sparmannia africana (African linden tree)|
The stamens of theses 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.