DND - I've had several seed pods do what yours did in reference to the photo on that link.
This is a bit different in the fact that the entire seed pod is opening revealing very plump, white, immature seeds. I did pull one off from the top and squeezed it to make sure no bug larvae or anything had made their home inside the seed. It just squirted out what appears to be clear liquid. Definitely not ripe seeds. The pod was large, but not ripe yet. Very green. Seeds were completely white. No black yet.
What would cause this to happen? I've never seen this before.
It is a cross that was hand-pollinated on (I believe) May 15th Wild One x Galaxy Explosion.
