Essential oil of Lavender 
Lavandula angustifolia
Synonyms: True lavender, Common lavender
click here for medical references on lavender

    A woody, evergreen shrub with pointed, narrow leaves and purple flowers. L. angustifolia has no side shoots on the main stem. True lavender grown at higher altitudes has a different chemistry than that grown at lower altitudes, and tends to be more calming.
    There are many varieties of lavender, with varying therapeutic properties.  True lavender is not to be confused with spike lavender (Lavandula latifolia). The chemistry and properties of spike lavender are quite distinct from true lavender. Spike lavender is a stimulant, with a camphorous scent.
    There is a third lavender, called lavendin (Lavandula intermedia), with four varieties that are useful in clinical aromatherapy.

Image by Thomas Schoepke - www.plant-pictures.com