Gardenia thunbergia (white gardenia)

The large, showy, creamy-white flowers of the white gardenia have an overpowering scent, which is particularly noticeable at night and typical of moth-pollinated plants.

Gardenia thunbergia (Image: Wikimedia Commons)

Species information

Scientific name: Gardenia thunbergia Thunb.
Common name(s): white gardenia, buffelsbal
Synonym(s): There are a number of synonyms for this species. View the World Checklist for details.
Conservation status: Least Concern (LC) according to Red List of South African Plants 2009, following the IUCN Red List criteria.
Habitat: Evergreen forest and forest margins.
Key uses: Ornamental, medicinal, as a raw material.
Known hazards: None known.

Taxonomy

Class: Equisetopsida
Subclass: Magnoliidae
Superorder: Asteranae
Order: Gentianales
Family: Rubiaceae
Genus: Gardenia

About this species

There are approximately 200 species of Gardenia, named after a Scottish doctor and keen amateur botanist, Dr Alexander Garden (1730-1791). Gardenia thunbergia, one of only six species from South Africa, commemorates the Swedish physician and botanist, Carl Peter Thunberg (1743-1828) who spent many years studying the botany of the Cape, eventually producing his enormous Flora of the Cape.

Geography & Distribution

Gardenia thunbergia grows along the eastern coast of South Africa, from the Eastern Cape to the north of KwaZulu-Natal, and in southern Mozambique. It is usually found in evergreen forest and on forest margins but occasionally in woodland and on the veld (dry habitat in southern Africa dominated by grasses and low shrubs).

Description

Gardenia thunbergia fruits (Image: Wolfgang Stuppy)

This evergreen shrub or small tree grows up to 5 m high and has a smooth, whitish, main stem and clusters of glossy green leaves at the ends of short branches. The flowers are large, creamy white and highly scented, with eight petals. They are borne from October to March and thought to be pollinated by moths. The flowers are followed by woody, greyish, egg-shaped fruits. These hard fruits are difficult to open, and the seed needs to be extracted by smashing or sawing through the woody shells.

Illustration from Curtis's Botanical Magazine

Hand-coloured engraving of Gardenia thunbergia by Sydenham Edwards (1807), taken from Curtis’s Botanical Magazine (Image: RBG Kew)

Curtis’s Botanical Magazine (Editor: Martyn Rix) provides an international forum of particular interest to botanists and horticulturists, plant ecologists and those with a special interest in botanical illustration.

Now well over two hundred years old, the Magazine is the longest running botanical periodical featuring colour illustrations of plants. Each four-part volume contains 24 plant portraits reproduced from watercolour originals by leading international botanical artists. Detailed but accessible articles combine horticultural and botanical information, history, conservation and economic uses of the plants described.

Published for the Royal Botanic Gardens, Kew by Wiley-Blackwell Publishing.
See the Wiley-Blackwell Subscription Information page for rates (for both print and online).

Threats & Conservation

The species is not threatened across its entire range but has been recorded as rare in the Cape.

Uses

Gardenia thunbergia is grown as an ornamental. The roots, leaves, bark and latex are used in African traditional medicine. The wood is used to make tools, tool handles and buttons. There has been some laboratory research on the molluscicidal properties of G. thunbergia.

Cultivation

White gardenia has the characteristic showy Gardenia flower. Its amazing scent makes it a welcome addition to the conservatory in Britain and, given favourable conditions, it can grow to a large shrub. Plants can also be propagated by cuttings.

Gardenia thunbergia can grow in any frost-free climate, provided that it has ample rain in summer or is watered through the year. It is best in a slightly acid soil with ample humus and will thrive in sun or part shade. Any pruning needed should be done soon after flowering.

This species at Kew

Marianne North painting 398 - Two Flowering Shrubs of Natal and a Trogon

White gardenia can be seen growing in the Palm House at Kew.

Alcohol-preserved specimens of Gardenia thunbergia are held in Kew’s Herbarium, where they are available to researchers from around the world, by appointment. The details of one of these specimens can be seen on-line in the Herbarium Catalogue.

Kew’s Economic Botany Collection includes fruit, stem and wood samples of Gardenia thunbergia.

The botanical artist Marianne North also depicted Gardenia thunbergia in her painting Two Flowering Shrubs of Natal and a Trogon that can be seen in the Marianne North Gallery.

Useful Links

Search Kew's databases for more information on this species

Find out more about the coffee family (Rubiaceae) at Kew

SEPASAL (Survey of Economic Plants for Arid and Semi-Arid Lands)

PlantzAfrica – Gardenia thunbergia

Curtis’s Botanical Magazine (Wiley-Blackwell)

References and credits

Anon. (1990). Wild Flowers of South Africa. Approved by the National Botanic Gardens of South Africa, Kirstenbosch, p. 121. Struik Publishers, Cape Town.

Raimondo, D. et al. (2009). Red List of South African Plants 2009. Strelitzia 25. South African National Biodiversity Institute, Pretoria.

World Checklist of Selected Plant Families (2010). Gardenia thunbergia. The Board of Trustees of the Royal Botanic Gardens, Kew. Published on the Internet at: http://apps.kew.org/wcsp/namedetail.do?name_id=88497 (accessed 15 August 2011).

Kew Science Editor: Martyn Rix
Kew contributors: Aaron Davis and Steve Davis (Sustainable Uses Group)
Copyediting: Malin Rivers

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