Mystery Low-Growing Plant with Papery Seed Pods

The plant you saw last fall—quart-sized, paper-thin leaves/seed pods atop thin stalks, seeds visible inside, used in 1970s dried arrangements—sounds like money plant (honesty), Lunaria annua. Its translucent, coin-shaped seed pods (silicles) are iconic in dried bouquets.

Other possibilities: Physalis (Chinese lantern) has papery husks, but they're orange and lantern-shaped. Nigella (love-in-a-mist) has inflated, striped pods.

To identify: Revisit the site in spring when foliage is present. Take photos of leaves, flowers, and pods. Show them to a local nursery or extension office. Lunaria is a biennial; it forms a rosette the first year, blooms and sets pods the second.

It's not typically invasive, but it self-sows readily. If you want to grow it, scatter seeds in fall or early spring in partial shade.