| Gardenia jasminoides | |
|---|---|
| Scientific classification | |
| Kingdom: | Plantae |
| (unranked): | Angiosperms |
| (unranked): | Eudicots |
| (unranked): | Asterids |
| Order: | Gentianales |
| Family: | Rubiaceae |
| Genus: | Gardenia |
| Species: | G. jasminoides |
| Binomial name | |
| Gardenia jasminoides J.Ellis |
|
| Synonyms | |
|
Gardenia augusta (L.) Merr. (nom. illeg.) |
|
Gardenia jasminoides, (common gardenia, cape jasmine or cape jessamine) is a fragrant flowering evergreen tropical plant, a favorite in gardens worldwide. It originated in Asia and is most commonly found growing in Vietnam, Southern China, Taiwan, Japan and India. With its shiny green leaves and fragrant white summer flowers, it is widely used in gardens in warm temperate and subtropical climates. It has been in cultivation in China for at least a thousand years, and was introduced to English gardens in the mid 18th century. Many varieties have been bred for horticulture, with low growing, and large- and long flowering forms.
Contents |
Gardenia jasminoides was described by English botanist John Ellis in 1761, after it had been conveyed to England in the 1750s.[1] It gained its association with the name jasmine as the botanist and artist Georg Dionysius Ehret had depicted it and queried whether it was a jasmine as the flowers resembled the latter plant. The name stuck and lived on the old common name and scientific epithet.[1] The name G. augusta of Linnaeus has been ruled invalid.
The common names cape jasmine and cape jessamine derive from the earlier belief that the flower originated in Cape of Good Hope, South Africa.[1]
Gardenia jasminoides is a shrub with greyish bark and dark green shiny leaves with prominent veins. The white flowers bloom in spring and summer and are highly fragrant. They are followed by small oval fruit.[2]
Gardenia jasminoides is generally considered to be somewhat difficult to take care of.
As a tropical plant, it thrives best in warm temperatures in humid environments. Getting those conditions is rather hard when in non tropical latitudes, reason for which gardenias are usually cultivated indoors or in greenhouses. In warm places, though, it can be grown outdoors. Either way, it prefers bright indirect sunlight or partial shade, rather than direct sunlight.
Apart from the difficulties in creating the suitable conditions for the plant to live, Gardenias need to be planted in an acidic soil (it is an acidophile plant). If the soil is not acid enough, many of its nutrients (especially iron compounds) will not be available for the plant, since they won't dilute in water and therefore won't be absorbed via the roots. It this happens, gardenias start to develop chlorosis, whose main symptom is a yellowing of the leaves. (See Soil ph).
For this reason, it's advisable not to water Gardenias with very hard water. When having to water with hard water, it is possible to add some vinegar or lemon juice to it before doing so, this will lower the pH of the water.
Iron chelate can be added to the soil in order to lower the pH, but care must be taken since an overdose can kill the plant, as with any other inorganic soil amendment.
Some gardeners will spill vinegar over the soil to effectively keep the pH low and prevent chlorosis. This can be carried out either regularly or when the first symptoms of chlorosis have been spotted.
Evidence of Gardenia jasminoides in cultivation in China dates to the Song Dynasty (960-1279 AD), where both wild and double-flowered forms have been depicted in paintings, such as those of the Song Emperor Huizong,[3] and the Tenh century artist Xu Xi.[4] The Yuan Dynasty (1271–1368) saw it on lacquerware, and the Ming Dynasty on porcelain (1368–1644).[5] Gardenias were seen in nurseries in Guangzhou in 1794 by English statesman Sir John Barrow.[5]
Meanwhile, was first propagated in England in August 1757 by a James Gordon of Mile End, and sold well thereafter.[1]
It is widely used as a garden plant in warm temperate and subtropical gardens. It can be used as a hedge. It requires good drainage and a sunny location, and prefers a mildly acidic soil. Many cultivars have been developed. G. 'Radicans' is a low-growing groundcover which reaches 15–45 cm (6–18 in) and spreads up to a metre wide, while G. 'Fortuniana' and G. 'Mystery' are double-flowered cultivars.[2] The former was sent by Scottish botanist Robert Fortune in 1844 to the Royal Horticultural Society in London.[5] G. 'Aimee' is an early-flowering (spring) form.[6] Cultivars such as G. 'Shooting Star' and G. 'Chuck Hayes' are more cold-hardy, roughly to zone 7.[7][8] A new cultivar called Summer Snow is a hardier breed with a greater resistance to cold climates, growing in USDA Zones 6-10.
The fruit is used as a yellow dye,[5] which is used for clothes and food (including the Korean mung bean jelly called hwangpomuk).
Polynesian people in the pacific islands use these fragrant blooms in their flower necklaces, which are called Ei in the Cook Islands, Hei in French Polynesia and Lei in Hawai'i
Gardenia jasminoides fructus (fruit) is used within Traditional Chinese Medicine to "drain fire" and thereby treat certain febrile conditions.
In one animal study Gardenia jasminoides significantly lowered serum IL-1β and TNF-α levels in rheumatoid arthritis rats, and its effect had a close relation with inhibitory development of rheumatoid arthritis in the rats.[9]
A mice study found that genipin was an active constituent in Gardenia that regulated inflammatory activity.[10] Geniposide from Gardenia enhanced glutathione content in rat livers. Glutathione is an important immune system amino acid that helps determine modulation of immune response, including cytokine production.[11]