It's a seed pod and each contains a varying number of seeds.

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You can tell if the seeds are ripe by the color and elongation of the coil. The one in the picture is ready. The coil turns brown and lengthens out.

It's probably about time for them to be ripe now in your zone.

Thanks Donn. Mine are still green and the stem is still tightly coiled. Its been a cool wet summer here so maybe that has delayed things. I will watch them closely.

I checked my own last night (c. hederifolium), not quite there although turning brown and softer to the touch, mid July is about normal ripening time. When ripe, the end of the 'ball' away from the coiled stem will begin to open with a very gentle pressure of two fingers - in the meantime, it will gradually begin to feel less firm.

As Donn said, several seeds in the pod. For those you might want to keep for yourself, I sow them immediately in pots topped with grit. They will germinate in September, winter over outdoors in the same pot while developing the corm.