Potpourri is a mixture of dried, fragrant plant materials used to provide a pleasant scent in homes and other spaces. The three ingredients for potpourri listed in the crossword are orrisroot (9 letters), PETAL (5 letters), and rosepetal (9 letters). Orrisroot is a type of iris flower root that has a sweet, earthy scent. Petals are the colorful parts of flowers that often have a pleasant smell. Rosepetals are the petals of roses, which are known for their strong, sweet scent. All three of these ingredients can be used to make potpourri.