Bit of a challenge given the way it’s modeled. You could make it editable, make a copy, edit the copy (keeping the same polygon count/structure) to make a baby plant, and then use a morph tag to create the effect.
Depends on your exact setup, but I would probably have the tracer reference a duplicate cloner and then apply a random effector to the duplicate with the visibility parameter active. Only the visible clones will be traced.
You can do it using Thinking Particles by way of the PMatterWaves node. First animate the alpha noise. Then copy it. In the MatterWaves node settings, set birth type to texture and then paste your alpha noise into the birth texture slot.