Under ideal conditions one duckweed frond can produce 17,500 “daughters” in just two weeks. Individual duckweed plants are 1/8 inch to 1/4 inch wide. If you don’t have containers, check with your local recycling center. “Wayne, if duckweed is sun-dried and seeds are present, would the seeds possibly be viable once the dried duckweed is placed in a water body again?”, His response, “That is an excellent question.
2020 does duckweed have seeds