buttons on alliums after blooming

Question

What are the little type buttons on the allium flowers after they are finished blooming?  i.e., after the flowers fall off.

Answer 1

These are the seed heads that form after flowering. Seed heads can be harvested.

Cut the seed heads as they start to break open.
Bring them indoors and let them dry out.

Gently tap out the seeds and store them in labelled paper envelopes.

This article will help.

https://www.gardeningknowhow.com/ornamental/bulbs/allium/allium-post-bloom-care.htm