Lavender : Lavandula angustifolia
Part Used: leaves
Method of extraction: Distillation 
Therapeutic properties: Lavender essential oil is one of the most popular and versatile essential oils used in aromatherapy. Distilled from the plant Lavandula angustifolia, the oil promotes relaxation and believed to treat anxiety, fungal infections, allergies, depression, insomnia, eczema, nausea, and menstrual cramps.