Give them a few more months to ripen and turn red and they will be quite beautiful. Odd that you do not get seedlings....I just toss my seedheads in the garage for the winter (after they are ripe of course) and then plant the whole things out in the woods (I do not remove the seed from the pulp....there is absolutely no reason to do this in my experience with quite a few species) and the next thing you know there are hundreds of seedlings everywhere to feed the slugs :o) Dan

Here's my update.

Arisaema triphyllum seeds began turning red in late August. Both the foliage and the fruit stalk turned yellow, collapsed to the ground, and eventually disappeared. But the bright red fruit still sits on the ground undisturbed.

Arisaema sikokianum seeds remain green and plump. The foliage has collapsed, but the fruit stalk remains upright.

Arisaema flavum seeds began turning red in late August and the plant collapsed to the ground. The ripe red fruits were eaten by ants and by a Harvestman (Daddy Long Legs). After a few days, all that remained were the seeds.

Tom