Iris foetidissima, the stinking iris,[1] gladdon, Gladwin iris, roast-beef plant, or stinking gladwin, is a species of flowering plant in the family Iridaceae, found in open woodland, hedgebanks and on sea-cliffs.

Its natural range is Western Europe, including England (south of Durham) and also Ireland, and from France south and east to N. Africa, Italy and Greece.

It is known as "stinking" because some people find the smell of its leaves unpleasant when crushed or bruised,[1] an odour that has been described as "beefy".

Its common names of 'gladdon' and 'gladwyn' or 'gladwin', are in reference to an old word for a sword, (Latin 'gladius') due to the shape of the irises leaves.

Both the species[4] and its cultivar 'Variegata'[5] have gained the Royal Horticultural Society's Award of Garden Merit.