Ministry of Agriculture, Food and Rural Affairs

Stems & Roots: Stems erect, 10-60cm (4-24in.) high, lower part with short, downward-pointing hairs.

Leaves: Alternate (1 per node), often in a dense rosette in late autumn and early spring, dark green to blackish-green, oblong in general outline, pinnately cut or divided into coarsely lobed segments, the bottoms of the spaces between segments more or less rounded.

Flowers & Fruit: Flowers similar to Wild mustard but pale yellow, the lowermost several flowers and pods of each raceme in axils of small leaves; seedpods 2-5cm (4/5-2in.) long, with a narrow beak about 3mm (1/8in.) long, on slender stalks, pointing outwards and upwards; seeds oval, reddish-brown, about 1.2mm (1/20in.). Flowers from late May to late fall.

Habitat: Dog mustard occurs throughout Ontario but is more common in the south. It is frequently found around railway yards, waste places, orchards, gardens, roadsides and occasionally in grainfields.

Similar Species: It is distinguished from most other plants of the Mustard Family in Ontario by having several of its lowermost flowers and seedpods in the axils of small leaves. Only Garlic mustard also has this characteristic. Rosettes of young plants resemble Tumble mustard but Dog mustard leaves are usually darker in colour, the segments are broader and more coarsely lobed, and the tips of the lobes are usually rounded in Dog mustard but somewhat sharp-pointed in Tumble mustard.