If you drink Earl Grey you already know this smell. Bergamot is the citrus that gives the tea its lift, and the oil is cold pressed straight from the peel of Citrus bergamia grown in Italy and France.

It is more complicated than a plain citrus: the sharp top note is layered over floral, herbaceous and slightly sweet notes that sit closer to lavender than to lemon, which is why it blends so easily with both. Plant Therapy's diffusion rate is three to four drops per 100 mL of water, and the topical range is 2 to 5 percent in a carrier. It carries the maker's KidSafe, Pregnancy Safe, Nursing Safe and Pup and Pony Safe designations.