I think either its frass from the caterpillars or its still chaff. Either way I threw it in the freezer in a jar. And it will get lots of washing. Haven't cooked any yet. Been too busy canning and eating fresh corn!
Growing it was easy. I planted in seed trays then transplanted late May. I nibbled on the greenery once and awhile for a salad. Slightly spicey but nice. It does look a lot like lamb's quarters, which is also an edible green.
Im going to grow it again next year in pots, so when its near harvest, I will skoot it under my west facing front porch to keep the foliage and seed heads
dryer. I use a dolly to haul big pots about. Give it a go, if you love quiona. Nothing to lose but time.
Amaranth next year!