Dehiscence (botany)

Dehiscence is the splitting of a mature plant structure along a built-in line of weakness to release its contents.

Structures that do not open in this way are called indehiscent, and rely on other mechanisms such as decay or predation to release the contents.

Explosive dehiscence is a ballistic form of dispersal that flings seeds or spores far from the parent plant.

A notable example is the sandbox tree (Hura crepitans), which can fling seeds 100 meters (300 ft) and has been called the "boomer plant" due to the loud sound it generates.

Ecballium elaterium, the "squirting cucumber", uses explosive dehiscence to disperse its seeds, ejecting them from matured fruit in a stream of mucilaginous liquid.

Septicidal and loculicidal dehiscence may not be completely distinct; in some cases both the septa and the walls of the locules split.

This process is coordinated precisely with pollen differentiation, floral development, and flower opening.

If the pollen is released through a split that is positioned to the side, towards other anthers, rather than towards the inside or outside of the flower, this is latrorse dehiscence.

This creates a tension that eventually leads to the anther being split along its line of weakness and releasing pollen grains to the atmosphere.

At maturity, the dehiscence zone is effectively a non-lignified layer between two regions of lignified cells in the valve and the replum.