[Knotweeds and Smartweeds: The Genera Bistorta, Fallopia, Persicaria and Polygonum in the Columbia River Gorge of Oregon and Washington]

Giant Knotweed

Fallopia sachalinensis

Synonyms: Polygonum sachalinense, Reynoutria sachalinensis, Tiniaria sachalinensis

Giant Knotweed: Fallopia sachalinensis (Synonyms: Polygonum sachalinense, Reynoutria sachalinensis, Tiniaria sachalinensis)

What appears to be giant knotweed growing behind the restroom facilities at the Memaloose Rest Area (eastbound) off Interstate 84 to the east of Mosier, OR.........October 12, 2011.

Cordate stem leaf of Giant Knotweed: Fallopia sachalinensis (Synonyms: Polygonum sachalinense, Reynoutria sachalinensis, Tiniaria sachalinensis) - Giant Knotweed: Fallopia sachalinensis (Synonyms: Polygonum sachalinense, Reynoutria sachalinensis, Tiniaria sachalinensis)

Inflorescence and stem leaf of Giant Knotweed: Fallopia sachalinensis (Synonyms: Polygonum sachalinense, Reynoutria sachalinensis, Tiniaria sachalinensis) - Giant Knotweed: Fallopia sachalinensis (Synonyms: Polygonum sachalinense, Reynoutria sachalinensis, Tiniaria sachalinensis)

Additional close-up photos of what appears to be giant knotweed growing behind the restroom facilities at the Memaloose Rest Area (eastbound) off Interstate 84 to the east of Mosier, OR.........October 12, 2011. Note the cordate (heart-shaped) leaf bases.
Paul Slichter