invasive knotweed begins to bloom in the summer

american asian bamboo begins biodiversity bloom branch clusters curse cuspidatum donkey ears elephant fallopia fleece fleeceflower flowering flowers fungus green hancocks heartshaped himalayan huzhang infestation intruder invasive itadori japanese japonica knot knotweed leaves mexican monkey monkeyweed pain pea perennial plume polygonaceae polygonum remove reynoutria rhubarb sally shooters small start stem summer threat vine weed white whitegreen wild zigzag