Botany is defined as the scientific study of plants; that is, in basic terms, understanding how a plant is structured and its ecological relationship to both the environment and its interactions with other plants and organisms. Botany is a broad, and complicated, area of study, yet having a basic knowledge of botany can help greatly with understanding the study of aromatherapy.
Aromatherapy is commonly defined as the art and science of using the essential oils of plants in a variety of treatment methods. Essential oils are extracted from various parts of a plant; the root, flower, leaf, fruit and from trees (including bark). The essential oils are situated in tiny glands, hairs, veins or sacs of the plant and it is in fact the aroma, or smell, of the plant which is used in aromatherapy.
Why Plants Have Aromas
Plants evolved with a number of capabilities to equip them in dealing with the world around them. Plants developed an aroma, or smell, for both attraction and defense reasons. If the aroma is found in the root, bark or leaf of a plant it is there to defend the plant against predators; if the aroma is situated in the flower or fruit it is a signal to others for pollination and dispersal of seeds.
The aroma of flowers attracts potential pollinators, in addition to the color and shape of a particular flower. The aroma does not necessarily have to be a pleasant smell; rotting fruit is attractive to tropical bats. However, the heady scent of night blooming Jasmine (Cestrum noctiflorum) is irresistible to hawk moths from a considerable distance.
The leaves of a plant may contain defense mechanisms within the essential oils they hold. On a hot day, these essential oils evaporate, as all essential oils are volatile ( from the Latin volare: to fly) at or above room temperature. If a predator attempts to eat the leaves of a plant it may result in nausea or even death, as the leaves commonly contain the chemical compound of terpenes. Terpenes have also been known to hinder the growth of its neighbors if they enter the soil on watering.
Where Plants Store Essential Oils
Aromas in a plant are the by/end product of metabolism . They are stored in a variety of places:
- Oil or Resin Canals – tubular canals or ducts are formed when neighboring glandular cells move apart; these spaces store essential oils of the Apiaceae plant family such as Fennel (Foeniculum vulgare), Coriander (Coriandrum sativum) and Aniseed (Pimpinella anisum).
- Oil Cells and Resin Cells – cells, sometimes living, which fill with resin or oils of the Lauraceae plant family such as Cinnamon (Cinnamomum zeylanicum) and Bay Laurel (Laurus nobilis).
- Oil Reservoirs – the formation of secondary cavities from the disintegration of lysigenous secretory cell reservoirs of the Rutaceae plant family such as Lemon (Citrus limon)and Bergamot (Citrus bergamia).
- Glandular Hairs, Scales and Cells – single or multi cell convexities, on the surface of the plant's skin layer; found in the Lamiaceae plant family such as Rosemary (Rosmarinus officinalis) and Thyme (Thymus vulgaris).
The Connection Between Botany and Aromatherapy
It can be seen that by understanding the basic anatomy of a plant and its functions, specifically in relation to its aromas, or smells, it is easier to understand the functions of essential oils in plants prior to their extraction for aromatherapy. Further study of both botany and aromatherapy is needed to fully understand the relationship between plant families and the properties of the essential oils extracted from them.
References:
Davis, Patricia 2005 Aromatherapy An A-Z UK: Vermilion
Rose, Jeanne 1999 375 Essential Oils and Hydrosols USA: Publishers Group West
