From a single symptom such as fever, it is impossible to diagnose a disease. Similarly, the opposite-leaf characteristic alone will not help anyone classify a plant. But throw in a stem with a square cross section, fragrant leaves and flowers with an upper and lower lip, and you probably have a member of the mint family.
This group of over 200 related genera includes about 7000 species. Of these, about 220 belong to the Thymus genus, or thyme. In all species, the stems and flower clusters also grow opposite of each other. Garden thyme (Thymus vulgaris) is a tough plant that grows well in well-drained soil. Its seeds ended up in gaps between my backyard uni stones, where they germinated and eventually flowered. After carefully lifting a stone or two, if one transplants a thyme plant with enough intact roots, in a month or two, a tiny plant will grow into a full one-foot bush with woody stems. If it’s at the end of a slope where a little water can accumulate, you might even get a plant growing with minimal soil.
But what rubs off on one’s fingers if a little pressure is applied to the leaves? It’s an oil rich in thymol, a phenol derivative. Phenol, which does not have any of the carbons attached to the hexagonal ring, was once used as an antiseptic.
To find out, some Brazilian researchers did not use thyme but they extracted oil of thymol from a different plant (Lippia sidoides). When heat-sensitive natural products have to be extracted, rather than boiling them directly, steam from a different flask is passed over the sample. It collects the extract and then passes it through a condenser. Finally the liquified mixture trickles into a collecting flask.
The oil not only contained thymol(57%) but an isomer known as carvacrol(17%) An assortment of other terpenoids made up the rest of the plant’s essential oil.
Their results suggested that thymol and carvacrol have antibacterial activity against Streptococcus mutans, the primary species associated with the first stages of dental cavities.
The previous year other researchers investigated garden thyme’s essential oil to possess a wide range spectrum of fungicidal activity. The oil’s vapor exhibited long-lasting suppressive activity on molds from damp dwellings. It should be pointed out that although thyme’s oil also contains thymol(33%) and carvacrol (4%), its major component is the very similar, OH-less, para cymene(37%).
Other research reveals that thymol and origanum oil (has thymol and carvacrol) inhibit the growth of the honeybee’s two bacterial pathogens. This is interesting from an ecological perspective because the honeybee is thyme’s main pollinator.
More About Thyme:
1) an interesting link to an article about wild thyme and the distinct smells produced from different groups and how climate change has led phenolic types to show up unexpectedly in a basin in France. I like the quote, “Mean values in ecology don’t mean a lot, what is important is the extreme values […] because you get extreme mortality events, and that is what causes natural selection” http://scienceintheclouds.blogspot.ca/2013/02/changing-thymes-plants-ada…
2) Caraway thyme(Thymus herba-barona) has a strong pleasant smell similar to caraway. Some species are susceptible to fungal diseases if over-watered. If not cut back after flowering , the plants become too woody.
Antimicrobial activity of the essential oil from Lippia sidoides, carvacrol and thymol against oral pathogens.Braz J Med Biol Res, March 2007, Volume 40(3) 349-356
Letters in Applied Microbiology Volume 44, Issue 1, pages 36–42, January 20073.
Journal of essential oil research : JEOR ISSN 1041-2905 Vol. No. v. 6(3) p. 279-287