Eucalyptus Bubble Bath

Arching, gray-green trees native to Australia yield eucalyptus oil, prized for its invigorating character. Steamed distilled from the leaves, its essential oil reveals a fresh, clean fragrance.

A native of Southeast Asia made famous in Thai and Vietnamese cooking, lemongrass is a tropical grass with bright bluish-green leaves. Its essential oil is extracted through steam distillation, releasing a lemony flavor for which it is named.

Paraguay is home to the largest production of petitgrain oils, which are steam distilled from leaves of the bitter orange tree. Its citrusy fragrance is strong and bitter-sweet, with floral and woody nuances.

Named for Bergamo, the Southern Italy city in which it flourishes, this citrus is a cross between pear, lemon and Seville orange. Expressed from the ripe peel, its essential oil imparts a fruity sweetness in fragrances and flavorings, including that of Earl Grey tea.

A tree that thrives in cold boreal climates, fir is identified by its needlelike leaves, gray-green bark and cylindrical cones. Extracted through the leaves, its refreshing essential oil emits a lush, resinous scent that balances sweet and balsamic.