Botanical Name of Northern Dock: Rumex longifolius. Other Common Names: Dooryard dock, Gemüse-Ampfer (German), rumex à longues feuilles (French), gårdsskräppa (Swedish), by-skræppe (Danish), njoli (Icelandic), høymol (Norwegian) hevonhierakka (Finnish). Habitat: Northern dock is native to Europe (including Britain) and Western and central Asia. It has been introduced to North America. The plant thrives best in moist cultivated soil and is usually found in arable land, by roadsides, waste dumps, etc. It is often regarded as a troublesome weed. Description: Northern dock is a perennial plant that belongs to the knotweed family (Polygonaceae). It can grow from up to 60 cm