Sterculia foetida

Java olive (Sterculia foetida)
Scientific name	Sterculia foetida [1]
Common name	Java olive [2]
Genus	Sterculia [1]
Family	Malvaceae [1]
Order	Malvales [1][2]
Growth form	Spreading, umbrella-shaped deciduous tree; about 20 m is usual in one account, with larger trees approaching 40 m, while another account gives up to 115 feet [3][4]
Native range	Seasonally dry lowland tropics from southern and eastern Asia to Australia [3]
Flowers and fruit	Foul-smelling flowers followed by bright-red follicles containing blue-black seeds [4]
Propagation	Fresh seed; seedlings form long taproots [3]

Sterculia foetida, commonly called Java olive, is a large deciduous tree of the seasonally dry Old World tropics. Its horizontal branches give mature trees a broad, spreading crown, and its flowers are followed by bright-red follicles containing blue-black seeds.^[2][3][4]

Description

Sterculia foetida is an accepted species in the family Malvaceae.^[1] It is a soft-wooded, spreading deciduous tree with whorled horizontal branches and palmately compound leaves divided into about seven to nine leaflets.^[3][4]

Mature size varies with site and account. A usual height of about 20 m and an upper value near 40 m are given for the species, while the National Tropical Botanical Garden describes trees up to 115 feet. These figures are best treated as approximate rather than as a fixed garden size.^[3][4]

The flowers are unisexual and have an unpleasant odor. The species is dioecious, with male and female flowers on separate trees. After flowering, the tree produces scarlet to bright-red follicles; the seeds are described as blue-black when mature.^[3][4]

Cultivation

Soil and water

In its native range, Sterculia foetida occurs in lowland dry woodland and forest, as well as river-bank and coastal sandstone settings.^[3] A species-specific cultivation account recommends deep, fertile, moist but well-drained soil, with a preferred pH of about 6–7.5. In cultivation, retain moisture during active growth but avoid a permanently saturated root zone; the deep-soil recommendation is particularly relevant to a tree whose seedlings develop long taproots.^[3]

Sun and humidity

A sunny, sheltered position is the practical starting point for this tropical tree.^[3] Its broad crown and native occurrence in open or seasonally dry lowland settings indicate a need for more light than a closed-forest understory plant, while shelter from strong wind is useful for a large tree with soft wood. Warm tropical conditions and good airflow around wet foliage are preferable to a cool, exposed site.^[3][4]

Seasonal changes

The species is deciduous and is associated with a seasonal wet-and-dry climate.^[3] Keep the root zone supplied with moisture while leaves and new growth are active, then reduce irrigation as the tree enters its dry-season leafless period without allowing a newly planted tree to dry severely. Flowering and fruiting timing varies by climate; an observation from India places these events in the dry-season transition, but it should not be applied as a universal calendar for every growing region.^[3][5]

Propagation

Fresh seed is the documented propagation route. Seedlings form long taproots, so they should be planted into their permanent position promptly rather than held in shallow containers until the root becomes difficult to move.^[3] The National Tropical Botanical Garden also describes propagation from seed as readily successful in general terms.^[4]

At the genus level, warm sowing around 20–30 °C, removal of a softened aril and scarification are described as treatments that can help germination. This is genus-level propagation guidance rather than a guaranteed S. foetida result; seed freshness, treatment and provenance can change the outcome.^[3]

Flowering, fruiting, and harvest

Sterculia foetida is dioecious, so a male and a female tree are needed when the goal is seed production. The retrieved cultivation account lists insects and cicadas among pollinators, but it does not establish a universal pollination distance or bearing age.^[3] Flowers have an unpleasant odor and are followed by conspicuous red follicles that open to display dark seeds.^[4]

No fixed harvest calendar or maturity index is applied here. In a warm seasonal climate, observe the follicles as they develop and open rather than transferring the flowering dates reported for another region to a new site.^[3][5]

Fruit and uses

The seeds are described as edible in some accounts, but the safety information is conflicting. Raw seeds are also described as potentially poisonous or laxative/purgative, and roasting is advised in some traditional accounts. These reports do not establish a safe preparation or a universally edible product, so the seed should not be treated as food without authoritative, current safety guidance.^[3][4][5]

Photos

References

• ↑ [1] GBIF species match: Sterculia foetida.

• ↑ [2] Sterculia foetida — Plants of the World Online.

• ↑ [3] Sterculia foetida — Useful Tropical Plants.

• ↑ [4] Sterculia foetida — National Tropical Botanical Garden Plant Detail.

• ↑ [5] Sterculia foetida.

Image credits

• Starr-080305-3286-Sterculia foetida-habit-Ala Moana Beach Park-Oahu (24537933859).jpg — tree habit at Ala Moana Beach Park, Oahu, Hawaii; creator Forest and Kim Starr; CC BY 3.0 US; attribution: Forest and Kim Starr / CC BY 3.0 US.

• Starr-080305-3298-Sterculia foetida-flowers-Ala Moana Beach Park-Oahu (24610089140).jpg — flowers at Ala Moana Beach Park, Oahu, Hawaii; creator Forest and Kim Starr; CC BY 3.0 US; attribution: Forest and Kim Starr / CC BY 3.0 US.

• Starr-080305-3297-Sterculia foetida-leaves-Ala Moana Beach Park-Oahu (24610087100).jpg — leaves at Ala Moana Beach Park, Oahu, Hawaii; creator Forest and Kim Starr; CC BY 3.0 US; attribution: Forest and Kim Starr / CC BY 3.0 US.