Best time to start Liatris seed?

I have recently received some seed for some Mixed white, and pink colors of Liatris, also known to my mom as "Blazing star". I am curious since these are perennials, if i should sow them in the fall, or wait until next spring? I have only worked with fully matured plants that have already developed corms. Thanks!

You can sow the seeds right now or in fall, whatever you like. That's what would happen naturally - seeds would fall from the plant, and germinate when conditions were right (moisture, warmth), likely in spring. Even if they germinated earlier, it's not a problem - hardy plants have hardy seedlings, and these are very hardy plants.

Perennials take a couple of years to bulk themselves out enough to form flowers AND good roots.
altagardener is right to inform that you can start Perennials from seed more or less any time after they form seeds, My only concern for you would be IF you sow the seeds early, you could be left with a good amount of little seedlings to grow on, every few weeks you would have to repot the seedling into larger pots, this requires more space and attention over the winter months, I am not saying DON'T sow early, all I'm doing is pointing out the pro's and cons.
The pro for early sowing is the small plants have more time to form good root systems and this helps when planting outside in spring or when the soil has warmed up, it also (with some types of plants) help flowering to be a little earlier as the plants have had a longer baby/nursery treatment to get them to mature faster BUT it needs care and light and attention.

To wait till spring time next year for starting off the seeds, they will germinate faster, still require enough attention BUT they wont take up space inside AND my own opinion is after about 2 years, you wont be able to tell which seeds were planted indoors over winter or outdoors from spring. IF anything, I like spring time sowing as the temp, shade /Light watering etc is much easier to control for a novice BUT, Please dont forget, other factors can come into play, you may have good light indoors, plenty room for a lot of germinated seedling and both ways are fun, so just choose the time to suit you, your skills and your space.
Have fun and enjoy your new way of germinating your garden plants, there are many more ways for increasing your plants that is also fun to do so make a start and just enjoy, that's what gardening is really all about.
Kindest regards.
WeeNel.