What to call shedding seeds from American basketflower

I know when milkweed pods split open and begin dispersing seeds it is called dehiscing.

Is there a specialized name for the manner in which American basketflowers (Centaurea americana) migrate their mature seeds to the surface of the dried flowerhead when the surface is stroked?

I found this out when saving seedheads from dispersing seed in trailways where they would be promptly weeded or mowed as seedlings.


Technically, dehiscence is when any kind of fruit splits open to release seeds, so not just milkweeds. Also technically, what you’re calling Centaurea seeds are really fruit – dry ovaries tightly covering a single seed. They are indehiscent, since they don’t split open, but I don’t know of a technical term for their particular dispersal method. Botanists do love their terminology, though, so someone may have come up with something.


Thanks, it’s just such an unusual (to me) thing to find that stroking the dried flower head results in seeds (that are really the fruit) migrating up and practically spitting out of the dried flower head. Makes it much easier to collect them, too. I wonder if this is a dispersal strategy that may involve a specific animal? Would make sense to me if the seeds germinated better after passing through an animal’s digestive tract.

Many times, dispersal methods like this may result in seeds being released slowly over a period of time, and then something like ants gathering them and dispersing them further. Wind blowing the seedheads around or changes in humidity causing the seedheads to shrink and expand may have a similar result as you touching it.