If they dried on the plant, they should be fine. I wouldn't worry about them being too dry. Think of how a seed is sold commercially in a paper packet on a store display. Usually the problem with saving seed is they aren't dry enough, which leads to mold and rot.

Thank you so much Richard. They will be kept then.

If you haven't planted the seed yet... You may want to check that they are viable first. Think of echinacea seed just the same as sunflower seeds. You have a seed husk or shell... And then you have the seed inside it. A cone will be full of husks... But they aren't all full of seed. Vaible ones will be hard... And bulkier then just an empty shell. You can pinch them between you finger nails... Viable ones are hard and don't do anything. It they compress between you nails... It's empty.

You will need to stratify the seed to help insure germination. I let nature do it for me by sprinkling the seed where I want the babies to grow until I move them. I only just did this right on top of the snow outside...they will melt in, moisten, stratify and germinate when the snow finally melts off.

They wintersow well too