- Name also: Western Dock (USA)
- Family: Dock Family – Polygonaceae
- Height: 80–150 cm (30–60 in.). Stem erect, usu. unbranched up to inflorescenes, reddish, furrowed.
- Flower: Usually bisexual. Joint on flower-stalk near base. Perianth-segments in two whorls of three. Segments of outer whorl small, spreading. Inner whorl forms the fruit valves which are broadly ovate to triangular, usu. crenulate, and without pimples. Stamens 6. Pistil consists of 3 fused carpels, styles 3. Flowers in whorls forming racemes.
- Leaves: Spirally, basal leaves long-stalked, upper leaves’ stalks shorter. Leaves hairless, blade elongated–triangular (longer than broad), with cordate base, margins only weakly wavy.
- Fruit: Brown, sharply three-edged, glossy achene.
- Habitat: Along rivers, by lakes and the sea. In ditches, streams, and wetlands. Usually at or above the water-line.
- Flowering time: July–September
Docks (Rumex spp.) are a taxonomically difficult genus as the species hybridise frequently – Scottish dock especially with water dock (R. hydrolapathum), broad-leaved dock, (R. obtusifolius), Northern dock (R. longifolius), curled dock (R. crispus) and Asiatic dock (R. confertus). The valves enclosing the ripe fruit are often essential to identification..
Scottish dock is a perennial plant. It belongs to an intrageneric section in which the flowers are bisexual and the fruit valves are clearly longer than the fruit. This species is not demanding but prefers continental climate.
Very similar water dock (R. hydrolapathum) is rarer and more strictly an aquatic plant. These two species can be separated by their size and characters of the fruit valves. Water dock can be up to 2,5 m (8 ft.) tall, and each of its fruit valves has a pointed pimple.