Potpourri is properly a mixture of dried, naturally fragrant plant material, used to provide a gentle natural scent in houses. It is usually placed in a decorative wooden bowl.
Naturally scented plants used in traditional potpourri include:
Most modern potpourri however consists of any decoratively shaped dried plant material (not specifically from scented plants) with strong synthetic perfumes (and also often strongly coloured dyes) added, with the scent bearing no relation to the plant material used.