Tea tree oil comes from the leaves of the Australian melaleuca tree, also known as Melaleuca alternifolia. It produces cream bottlebrush-like flowers and pointed light green leaves that give off a fresh herbal aroma.

Peppermint, also known as Mentha piperita, is a hybrid plant of water mint and spearmint. It is indigenous to Europe and the Middle East. This plant has light purple flowers and serrated green leaves with a fragrant minty aroma.

Lavender, also known as Lavandula angustifolia, produces beautiful pinkish-purple flowers that give off an intoxicating floral aroma. It is a water-wise plant that is indigenous to the Mediterranean area of Europe.

The thyme plant, also known as Thymus vulgaris, is an herb indigenous to the Mediterranean region of Europe. It produces small needle-like leaves and pink-purple flowers with a spicy smell. There are more than 100 varieties of thyme.

The eucalyptus tree, also known as a blue gum tree or Eucalyptus globules, is native to Australia and has an herbal fragrance. It is a tall tree with white flowers and oval-shaped blue leaves that turn green as they mature.