Children (8 direct children, 8 direct and indirect children):
Polygonum douglasii var. johnstonii
Douglas' knotweed
Johnston's knotweed
Polygonum douglasii subsp. engelmannii
Polygonum douglasii subsp. majus
Polygonum douglasii subsp. nuttallii
Polygonum douglasii subsp. spergulariiforme
Polygonum douglasii var. utahense