hortster, I'm a big fan of tarragon, the "true" French variety that must be cloned, and I have a big bed of it from plants I originally got from Richter's in Canada. Hardiness is a problem with tarragon in Minnesota, but with proper mulching I've been able to keep the bed for three years now.

I can't account for what your plants are doing with the flowers, but from everything I've read those seeds, while viable (they'll germinate), will not produce the "true" French tarragon.

I'd be happy to hear others' experience and expertise on this.

Gary

French Tarragon is in the artemsesia family (Artemisia dracunculus). Most Artemesia's flower, some actually reproduce from seed. You are correct in saying that it seldom flowers. but it does, and it may have been stimulated to flower by the extreme heat, these being 'stress initiated'
The flowers are produced in small capitulae 2-4 mm diameter, each capitulum containing up to 40 yellow or greenish-yellow florets. I doubt if the seeds will be viable.

perennial gardener 2, thanks for reinforcing my suspicion that flowering may have been induced by the extreme temps. Being curious, if it does produce seeds I will naturally have to try them. Again, will recall this thread and post some pix of this unusual event.
hortster

Here is a pic. Crabgrass beneath paper sack backdrop is for scale! More to come in a few days.

It is noted in many articles that I have read over the years that Artemisias dracunculus French tarragon sometimes produces nondescript flowers that are usually sterile and do not yield viable seed, so plants must be purchased.

No matter what you read there is always an exception. If there wasn't there would be few variations among plants that are produced by cuttings.

Hortster I have seen other plants with the same what look like seed clusters. However when they were cut open there was not substance to the inside of the seed. If you are lucky there may be embryo's in the seeds.

If I remember correctly the ball contains from 4 to 6 individual seeds.