They're like huge seedpods.
3 seconds sound clip from the Invasion of the Body Snatchers (1956) movie soundboard.
You can hear this line at 00:41:16.700 in the Blu-ray version of the movie.
Quote context
[...]
- Onion or olive? Doesn't matter. I wanna pour it on the charcoal. I can't get this stuff to burn.
- A martini isn't dry enough. I'll get you something to start it.
- This must be the way that body in my closet was formed.
- I don't know. If they are seeds or seedpods they must grow someplace on a plant probably.
- Somebody or something wants this duplication to take place.
- But when they're finished what happens to our bodies?
[...]