How do the laser pods (mines) work?

Solution 1:

You got that right on the way they grow:

Laser mines (not pods) can grow only on defense trees and only one mine per tree can be alive at any given time. That means, if a mine gets destroyed, eventually a new one will grow on the tree from which the old one originated.

The stats of a mine are determined solely by the asteroid on which they grow. The stats of the seedlings or even the flowers that made the tree are not relevant.

I can confirm those information from my own experience playing the game, but it is also discussed and explained in this forum thread.

Solution 2:

Just adding to Sentry's answer, a defense tree only produces laser mines/pods if it has a flower added to it. So if the flower is lost, the tree won't produce laser pods.

I frequently use my mines to destroy enemies' flowers on enhanced Dyson or Defense Trees in asteroids with a few number of seeds.

http://en.wikipedia.org/wiki/Eufloria#Gameplay