Some plants disperse their seeds forcefully by ejecting them. Sometimes the tension is so great, seeds may be ejected up to 200 feet away from the mother plant. This method of seed dispersal is called “ballistichory,” a label that hints at the projectile-like emergence of seeds from their pods or capsules. This type of seed dispersal occurs because the fibers in the dried fruit pull against each other to create tension, and when the tension is great enough, the fruit splits open and the walls of the fruit spring back, flinging the seeds out with force.
Plants in the Fabaceae Family
Another plant that shoots seeds when touched is Euphorbiaceae. The Euphorbia family produces segmented seed capsules that somewhat resemble a peeled orange in shape. Examples of plants in this family include bitterbark (Petalostigma spp.), the sandbox tree (Hura crepitans), and the rubber tree (Hevea spp.)
Most Plants in Euphorbiaceae Family
One of the largest groups of plants that uses ballistichory is the pea family, or Fabaceae. This is just one type of plant that shoots seeds when touched and the pod is cracked open. Lupins (Lupinus spp.), a garden favorite that’s hardy in U.S. Department of Agriculture plant hardiness zones 3 through 9, form columns of pea-like fruits that burst open when dry. Orchid trees (Bauhinia spp.), hardy in USDA zones 9 through 11, bear large pods that can fling seeds nearly 50 feet. Gorse (Ulex spp.), an aggressive broom-type plant that is considered a noxious weed in some states, makes a popping noise when the seed pods burst open.
If there is one thing that I will never get tired of it’s finding out about new weeds. As I mentioned in an earlier blog post this year, there are an estimated 8,000 species of plants that are considered weeds. The word weed is defined as a “plant growing out of place.” Based on that definition, just about any plant could actually be considered a weed.
Ideally, the best time to remove this weed is before it produces its flowers. This plant grows best in cool, moist conditions, which, for the Pacific Northwest, means that this weed may germinate multiple times in the fall, winter and early spring.
I recently came back from visiting our newest Franchise Owner, in Silverdale, WA. It seems whenever that happens I always find some new weed that I have never seen before. This time, it was a weed called Shot Weed. Its seeds are “shot” out as the seed pod ripens later on in the year, spreading 100’s of weeds with each shot.