Sterculia foetida

Sterculia foetida

The bastard poon tree or Java olive tree, hazel sterculia, wild almond tree, skunk tree (Sterculia foetida L. 1753) is an arboreal species belonging to the Malvaceae family.

Systematic –
From a systematic point of view it belongs to:
Eukaryota domain,
Kingdom Plantae,
Division Magnoliophyta,
Class Magnoliopsida,
Subclass Dilleniidae,
Malvales Order,
Malvaceae family,
Subfamily Sterculioideae,
Genus Sterculia,
Species S. foetida.
The terms are synonymous:
– Clompanus foetidus (L.) Kuntze;
– Clompanus foetida (L.) Kuntze;
– Sterculia mexicana var. guianensis Sagot;
– Sterculia polyphylla R.Br.

Etymology –
The term Sterculia comes from the Latin “stercus”, i.e. dung, manure, with reference to the unpleasant smell of the flowers and leaves of some species. Sterquilinus was also the Roman god of fertilizer or manure
The specific epithet foetida comes from the Latin “foetidus, a, um”, that is, fetid, smelly, in reference to the unpleasant odor of the flowers.

Geographic Distribution and Habitat –
Sterculia foetida is a plant of uncertain origin but found in many areas, such as: India, Sri Lanka, Myanmar, Thailand, Bangladesh, Cambodia, Malaysia, Taiwan, Indochina, Philippines, United States (Hawaii), Indonesia, Ghana, Australia, Mozambique and Togo.
Its habitat is that of primary and secondary forests, generally on river banks and sandstone rocks along the coasts, as well as in thickets and open areas, at altitudes up to 1,500 meters.

Description –
Sterculia foetida is a large, dioecious, deciduous tree that grows up to 40 m.
The trunk is erect, the bark is greyish in color and the branches are almost horizontal arranged in whorls (3 or more inserted on the same node).
The leaves are grouped at the apex of the branches on a 10-30 cm long petiole, they are palmate-compound with 5-9 elliptical to lanceolate leaflets, 6-15 cm long and 2-5 cm wide, with an entire margin and a long apex. pointed, initially pubescent, then glabrous, of a shiny intense green color and an unpleasant odor.
The inflorescences are subterminal, erect panicles, which form before the leaves are released; they are composed of unisexual smelly flowers on the same plant, about 2 cm in diameter on a 1.5-2.5 cm long peduncle, without a corolla, with a bell-shaped calyx with 5 lanceolate lobes with retroflexed apex, yellowish in color at the opening , then red or purple, pubescent; male flowers with curved stem column about 1 cm long with 10-15 anthers grouped at the top, female flowers with gynophore (column that supports the ovary) about 0.6 cm long, five-lobed pubescent ovary and folded style.
The fruit is composed of 1 to 5 ellipsoid follicles, about 10 cm long and 7 cm wide, woody, initially green, then red, which open when ripe.
Inside there are 10-15 oblong slate-colored seeds, 1.5-2.5 cm long, arranged along the edges of the opening.

Cultivation –
Sterculia foetida is an attractive deciduous, dioecious, multipurpose tree, is often harvested from the wild and provides a popular food, as well as medicines and a range of materials for local use. It is an imposing and ornamental tree due to its foliage, inflorescences and showy infructescences, but with the disadvantage of the unpleasant and penetrating odor emanating from the flowers, it can be cultivated in full sun in tropical and subtropical climate zones, being rather sensitive to low temperatures.
The plant is often grown as an ornamental in many parts of the tropics, although its flowers are smelly.
It is a plant of warm, tropical lowlands, where it is found at altitudes up to 1,500 metres, where it grows best in areas where annual daytime temperatures are between 18 and 32°C, but can tolerate 16-36°C.
It prefers an average annual rainfall of between 1,100 and 1,800 mm, but tolerates 900 – 2,000 mm, growing in areas with or without a clear dry season.
From a pedological point of view, it prefers deep, fertile, moist but well-drained soil in a sunny and sheltered position and prefers a pH between 6 and 7.5, tolerating 5 – 8.
The plant reproduces by seed, previously kept in water for 24 hours, in organic soil with the addition of coarse sand or perlite, kept humid, at a temperature of 22-24 °C.
The seed germinates after 1-3 weeks forming a long taproot; initial growth is particularly fast.

Customs and Traditions –
Sterculia foetida is a plant known by various common names; among these are: australian flame tree, bangar nut, bastard poon tree, fetid sterculia, great sterculia, hazel bottletree, indian-almond, Java-olive, poon tree, skunk tree, star-chestnut, wild almond (English); xiang ping po (Chinese); kalumpang (Filipino); arbre puant, olive de Java, olivier putois (French); jangli badam (Hindi); janghang, kabu-kabu, kepoh (Indonesian); castanha-da-Índia, chichà, chichá-fedorento, oliva-de-java (Portuguese-Brazil); anacagüita, olive tree of Java (Spanish); chammahong, homrong, samrong (Thai); gorapu-badam, pee, pottaikavalam (Tamil); gewöhnlicher Stinkbaum (German).
The species was described in 1753 by Carl Linnaeus. It is the type species of the genus Sterculia and both names mean smelly.
The leaves are often used as fodder for livestock. The resin that exudes from the trunk and branches is used as glue. Finally, ropes are obtained from the bark.
The immature seeds are not edible, they can be consumed ripe and toasted, with a flavor similar to that of chestnuts (Castanea sativa Mill.), but in moderation having a laxative effect.
Evidence suggests that the seeds are edible, but purgative and should be roasted before eating. At least one review indicates that CPFAs such as sterculic acid are carcinogenic, co-carcinogenic, and have medical and other effects in animals; according to this review, “CPFAs in foods are dangerous to human health.”
Leaves and flowers are used in traditional medicine, as is the oil obtained from the seeds, whose main component (53%) is sterculic acid, which has proven to have interesting and promising pharmacological applications.
In Vietnam, the tree is called Trôm and its sap is collected to be used as a soft drink called “Mủ Trôm”.
The oil, which is obtained from this plant, also has an insecticidal activity and potential as biodiesel.
The oil is also used for lighting. An unusual feature of the seed is that oil is present in both the head and the kernel. The total oil content is approximately 34%.
Traditionally the oil is mixed with white earth and used as paint.
Sterculia foetida oil has been found to be comparable to sunflower, soybean and canola oils for use as a biofuel. Sterculia foetida oil contains cyclopropene fatty acids such as 8,9-methylene-heptadec-8-enoic acid (malvalc acid) and 9,10-methylene-ocadec-9-enoic acid (steric acid). Flash point, iodine number, free fatty acid number, phosphorus content, cloud point, viscosity at 40 °C, oxidative stability at 110 °C, density and number of trace metals are within ASTM and EN.7 specifications
The wood is pink in color, easy to work and finish, and is used in the construction of furniture and locally for boats and musical instruments.
It is easy to saw and work, finishes quite well, is very perishable if exposed to the elements or in contact with the ground, although it is durable enough for interior work.
A fiber is obtained from the bark. The fiber is the inner bark of the tree. It is used to make mats, bags, ropes and paper.
From the trunk and branches a gum resembling “gum tragacanth” is obtained, and is used for bookbinding and similar purposes.
Other uses include agroforestry as it is also used to control erosion.

Preparation Method –
Sterculia foetida is a plant that is used for various uses, from food to medicinal and for oil and other materials, as well as for ornamental or agroforestry use.
In the food sector, the seed can be consumed raw, roasted or fried (taking care of what was said before).
It is oily and has a pleasant flavor, similar to cocoa, but it is not bitter.
Once toasted it tastes like peanuts; if consumed in excessive quantities, however, it can have a laxative or purgative effect.
The tender parts of young plants can be eaten raw; they are a rich source of starch, with a flavor similar to jicama (Pachyrhizus erosus).
From the seed a non-drying edible oil is obtained; it is a bland, sweet-tasting, yellow oil with a rather high melting point.
It has similar properties and can be used in the same way as olive oil.
In the medicinal field the bark is experiential, diaphoretic and diuretic. It is used in the treatment of dropsy and rheumatism.
The leaves are open.
The fruit is astringent and mucilaginous and is used in the treatment of gonorrhea.
The seeds are used as a purgative in Ghana.
The oil from the seed is laxative and carminative and is extracted locally for use medicinally.

Guido Bissanti

Sources
– Acta Plantarum – Flora of the Italian Regions.
– Wikipedia, the free encyclopedia.
– GBIF, the Global Biodiversity Information Facility.
– Useful Tropical Plants Database.
– Conti F., Abbate G., Alessandrini A., Blasi C. (ed.), 2005. An annotated checklist of the Italian vascular flora, Palombi Editore.
– Pignatti S., 1982. Flora d’Italia, Edagricole, Bologna.
– Treben M., 2000. Health from the Lord’s Pharmacy, Advice and experiences with medicinal herbs, Ennsthaler Editore.

Photo source:
– https://inaturalist-open-data.s3.amazonaws.com/photos/279940971/original.jpeg
– https://upload.wikimedia.org/wikipedia/commons/9/9e/Sterculia_foetida_Blanco1.134-cropped.jpg

Attention: Pharmaceutical applications and food uses are indicated for informational purposes only, they do not represent in any way a medical prescription; we therefore decline any responsibility for their use for healing, aesthetic or food purposes.