Stinking mayweed is an annual that grows up to 40cm high and flowers from December to March. Flowers are white and yellow and 15-30mm across. Leaves are feathery and dark green, grow up to 8cm long and are divided three times into awl shaped segments. The very distinct smell obtained from rubbing the foliage makes mayweed easy to identify.
Mayweed is common throughout the North Island and the northern half of the South Island. It appears in farmyards, holding paddocks, roadsides, disturbed ground, waste places and pasture. Mayweed germinates strongly when pasture is cultivated for either a crop or renovation in the autumn or when pugging has occurred during the winter.
Stock will actively avoid the plant and nearby pasture.