Long, thin seed pods form a pretty star around the flower clusters of Hairy Bittercress, and a slight bump of these “siliques” is all it takes to witness the plant’s ballistic seed dispersal mechanism.
Why would a plant want to explosively disperse its seeds? Dispersing seeds over a wide area lessens competition between the parent plant and seedlings. Ballistic seed dispersal also serves as a defense mechanism. When an insect herbivore lands on a seed pod, it sets off an explosion that not only propels the seeds but, also, propels the insect off the plant. The wonders of nature never cease!
We keep this entertaining, although invasive, species from taking over the gardens by pulling it. Its fine, shallow roots make the task easy and, actually, somewhat enjoyable!
