Hura crepitans (Sandbox Tree)

Scientific name

Hura crepitansL.

Synonyms

Hura brasiliensisL.

Common names

Sandbox tree, possumwood, monkey's dinner bell, monkey's pistol

Family

Euphorbiaceae

Origin

Hura crepitans is native to the tropical regions of North and South America in the Amazon Rainforest.

Naturalised distribution (global)

Locations within which Hura crepitans is naturalised include northern Australia and eastern Africa.

Introduced, naturalised or invasive in East Africa

In East Africa, Hura crepitans is invasive in parts of Tanzania (Tropical Biology Association 2010). The editors found no records of its occurrence in Kenya or Uganda, though this does not necessarily mean that it is absent from these countries.

Habitat

In its introduced range, Hura crepitans occurs in forest edges and gaps.

Description

Hura crepitans is a tree growing to 40 meters high. It can be distinguished by its many dark, pointed (conical) spines. Its common name 'Monkey-no-climb is in reference to the characteristic spiny trunk.

The leaves are papery thin, heart-shaped and up to 60 cm long.

The berry look-alike structure is actually the male flowers that have no petals. Male flowers grow on long spikes; female flowers are solitary. Male flowers are ovoid to conical (5 by 2 cm), mostly dark red in colour. Flower stalks (pedicels) up to 10 cm long; female flowers without pedicel; fruiting pedicel pendant to 6 cm; fruit oblate (3-5 x 8-9 cm) in diameter, reddish brown on colour, concave at the tip and base, longitudinally grooved.

Fruits are pumpkin-shaped capsules, 3-5 cm in length with a diameter of 5-8 cm; it has 16 carpels arranged radially around the central axis. Seeds are flattened and about 2 cm in diameter.

Reproduction and dispersal

The fruit of Hura crepitans opens with an explosive sound into segments, hence the name 'dynamite tree'. Seeds are dispersed up to 14 metres away.

Economic and other uses

Hura crepitans is cultivated for medicinal and ornamental purposes.  The latex is used as arrow poison and is said to cause ailing teeth to fall out. As medicine, it treats skin diseases, rheumatism, intestinal worms and has been used in the United States of America to prepare tear gas; bark extract is used to treat leprosy and wood used in light construction.

Environmental and other impacts

The large leaves of Hura crepitans enable the plants to grow in deep shade, allowing the plant to establish in undisturbed forest outcompete indigenous vegetation. H. crepitans is among the 14 commoner causes of plant contact dermatitis in the Dominican Republic. Tree fellers have to cover their eye since the sap causes temporary blindness. The segments of the woody fruits can cause dermatitis when they are used in bracelets and necklaces.

Management

The precise management measures adopted for any plant invasion will depend upon factors such as the terrain, the cost and availability of labour, the severity of the infestation and the presence of other invasive species.

The best form of invasive species management is prevention. If prevention is no longer possible, it is best to treat the weed infestations when they are small to prevent them from establishing (early detection and rapid response). Controlling the weed before it seeds will reduce future problems. Control is generally best applied to the least infested areas before dense infestations are tackled. Consistent follow-up work is required for sustainable management.

The editors could not find any specific information on the management of this species.

Legislation

Not listed as a noxious weed by the state or governments in Kenya, Tanzania and Uganda.

Notes

The pumpkin-shaped fruit of Hura crepitans was once used for holding fine dry sand used for blotting ink before the introduction of blotting paper, hence the common name 'sandbox tree'.

References

Pacific Island Ecosystems at Risk (PIER). Hura crepitans: plant threats to Pacific ecosystems. Institute of Pacific Islands Forestry, Hawaii, USA.www.hear.org/pier/species/hura_crepitans.htm.  Accessed March 2011.

Tropical Biology Association (2010). Usambara Invasive Plants - Amani Nature Reserve - www.tropical-biology.org/research/dip/species.htm.

Editors

Agnes Lusweti, National Museums of Kenya; Emily Wabuyele, National Museums of Kenya, Paul Ssegawa, Makerere University; John Mauremootoo, BioNET-INTERNATIONAL Secretariat - UK.

Acknowledgments

This fact sheet is adapted from The Environmental Weeds of Australia by Sheldon Navie and Steve Adkins, Centre for Biological Information Technology, University of Queensland. We recognise the support from the National Museums of Kenya, Tropical Pesticides Research Institute (TPRI) - Tanzania and Makerere University, Uganda. This activity was undertaken as part of the BioNET-EAFRINET UVIMA Project (Taxonomy for Development in East Africa).

Contact

BioNET-EAFRINET Regional Coordinator: eafrinet@africaonline.co.ke