Carolina Cranesbill: Seed Dispersal

The seed head of Carolina Cranesbill (Geranium carolinianum) consists of a central spike or beak and seedpods. A finely veined (reticulated) seed is inside each seedpod.

As the seed head dries the seedpods split open on their bottom sides.



With the seedpods removed from the plant you can see the seeds inside.

At the same time, the central spike shrinks and splits along it length into separate strips. A seedpod is at the bottom of each strip. Because of the shrinkage, the strips want to curl but cannot because they are still attached at their tops and bottoms.

Eventually, the bottom connection on a strip breaks beneath the seedpod. The strip pops upward as if it were spring loaded, which in effect, it is. As the seedpod attached to the bottom of the strip arcs upward, the seed inside is toss out away from the mother plant.



Empty seedpods after they've popped upward and tossed the seeds they contained away from the mother plant.