How To Collect Poppy Seeds - THE EASIEST METHOD! I know that there are wild poppies and that there are ornamental poppies, but I'm sure dealing with the seeds is about the same either way.
Wild Flowers Growing from Seed 150-day Timelapse This featured wildflowers from the British Isles, but there are wildflower mixes for the desert that can be used.
How to Sow a Wildflower Patch with Hannah Grows Love the garden gnome and it's noteworthy that the Grow Wild seeds she uses are made available by the world famous Kew Gardens of the UK. LINK: https://www.growwilduk.com/
About the Theodore Payne Foundation This might be a good source for seeds and plants plus information about growing native plants and which plants to select for your particular growing conditions.