I'll never forget Pete Salmond's story about digging huge, many years old Trillium chloropetalum plants at Francie Herlund's place, and sinking his hands into what seemed to be fresh dog turds. A little exploration found they were large seed pods full of fresh, moist seed allowed to fall and eventually germinate in situ, a process that had been going on for years so that trilliums were layered on trilliums, on trilliums etc, thousand of plants in a single clump.