Our mystery seeds from last week were from whitestem paperflower (also called Cooper's paperflower or paper daisy), Psilostrophe cooperi.
The whitestem paperflower is a small perennial with the unusual characteristic that the flowers remain intact as they dry on the plant.
The fresh flowers are bright yellow.
The dried, papery flowers turn beige or cream color. They have a bundle of seeds inside.
This fun little plant is native to the Southwest. They bloom mainly in the spring, but may bloom again throughout the year.
As you can see, the whitestem paperflower doesn't have a lot of foliage, only very thin leaves covered with silvery or white hairs.
Just FYI, while looking for other photos of the seeds, I found the Rancho Santa Ana Botanic Garden has an extensive list of seed photographs. The list includes whitestem paperflower seeds (which they call paper daisy) and the related Helenium (sneeze weed).