|Gardenia jasminoides (the Cape jasmine)|
This shrub of the fragrant white flowers is redolent of tall tales. The genus name? Have you guessed an allusion to gardening? You would be wrong.
It refers instead to Alexander Garden (1730-1791), a physician and a natural historian. Originally from Scotland, he spent many years in Charleston, South Carolina, where he felt very isolated. He began corresponding with John Ellis, a London merchant with a penchant for plants. Ellis hungered for New World natural wonders, and Garden obliged by sending cases of cuttings and corms and samples of various magnolias and some Gordonia specimens. Ellis then relayed samples of the most unusual, so far unknown or unfamiliar species to the then pope of systematics, Carl Linnaeus in Uppsala, Sweden. Afterwards, Linnaeus had to be pushed into naming a plant after Garden, but eventually Ellis convinced him to use Gardenia as a name for the Cape jasmine, also known as Cape jessamine. The irony is that the Cape jasmine had nothing to do at that time with the Americas, it originated in the Far East, China, Taiwan and Japan.
A more recent (2010) tall tale is that the jasmine-like smell acts as an anti-depressant which might be substituted for valium. The molecules, of the chemical family of 1,3-dioxanes, responsible for the endearing perfume of the gardenia, known as vertacetal-cœur in the idiom of perfumers carry a fresh, green-floral odor. The distant basis for possible use in aromatherapy is that these molecules strongly and selectively bind to type A GABA receptors that contain a protein named a β1 subunit. GABA is an inhibitory neurotransmitter in the brain, which regulates over-excitement. Low levels of GABA correlate with anxiety. Thus, drugs that increase the amount of available GABA in the brain serve as anxiolytics.
Is that the case with the scent of gardenias? We simply cannot say. The binding study, from the University of the Ruhr, in Bochum, Germany, used egg cells from frogs that had been genetically engineered so that GABA receptors would be displayed on their surface. Ex-trapolation to the brain and to the human species is unwarranted at this stage. It expresses the journalistic rush to utilitarian conclusions that, in the end, is self-defeating.
We’d better just enjoy gardenias for their loveliness: their glossy, dark green leaves two to four inches long, generally in whorls of three; their big waxy flowers, terminal or axillary, funnel-shaped with five to 12 spreading lobes, up to three inches across, white to ivory, very fragrant and often grown in double-flowered forms.