Dodonaea viscosa (hopbush)
Dodonaea viscosa in Bolivia (Photo: J.R.I. Wood, Darwin Initiative Project)
Dodonaea viscosa Jacq.
hopbush, hopseed, hopwood, soapwood, candlewood. A full list of common names is found below.
Generally occurring in open habitats, including open woodland, on well-drained soil in tropical and subtropical climates.
Contains low levels of toxic chemicals known as cyanogenic glycosides. Although there are no recorded cases of human poisonings it should be treated with caution. It is known to cause liver damage in cattle.
About this species
Hopbush is a highly variable evergreen shrub or small tree with several subspecies and varieties. It occurs around most of the southern hemisphere, and its numerous useful properties have been discovered independently by people of different continents. The flowers are relatively unspectacular but its winged fruits can become red or purple as they mature, making it an attractive garden plant in the tropics and subtropics. One cultivated variety also develops purple leaves when grown in direct light. The scientific name, Dodonaea, refers to Rembert Dodoens (a 16th century Flemish royal physician, botanist and professor), viscosa to the stickiness of its leaves.
Geography and distribution
Widely distributed through the southern hemisphere including Australia, New Zealand, South and Southeast Asia, Africa and Latin America; also occurring in the southern United States. It is tolerant of drought and can grow in coastal environments. It is intolerant of frost and does not grow well in shade.
Hopbush is an evergreen shrub or small tree, which grows up to about 5 m in height. The leaves are variable in shape, from elongated to spoon- or wedge-shaped, are sometimes reddish or purplish, and are usually shiny and sticky to the touch. They generally have conspicuous veins and their edges may be weakly toothed or undulating. The flowers, which grow at the ends of the branches, are either male or female, and individual plants generally bear one or the other (in which case plants of both sexes are required for successful reproduction). In other cases, however, they may bear flowers of both sexes. The pollen is transported by the wind, and the lack of petals maximises exposure to the breeze. The female flowers, after pollination, develop into 3 or 4 winged papery capsules, each with 2-3 black seeds. These capsules turn red or purple as the fruit matures.
More common names for this species
'A'ali'i, 'a'ali'i kü makani ("'a'ali'i upright in the wind") [Hawai'i]; ake, akeake, akerantangi [Nz]; alipata [Philipines (Tagalog)]; 'apiri [Tahiti]; bandari [India]; calapinai [Philipines (Tagalog)]; candlewood, dogwood [Bahamas]; chacataya [Bolivia]; chamana [Ecuador, Peru]; chamiso [Argentina]; chanamo, hayuelo [Colombia]; chapuliztle, cuerco de calva, granadina [Mexico]; chulita [Guatemala]; florida, hopbush, hopshrub [England]; gansies [Afrikan]; gelampaya, serengan laut [Malaya]; gitaran [Puerto Rico]; granadillo, hayo [Venezuela]; hopbush, native hop [Australia]; hopwood [England]; kabunda [Congo]; kankerbos [Afrikan]; kayu berthi. letup letup [Malaya]; kayu mesen, kisig, mesen [Java]; kharata [India]; mai pek [Thailand]; manglier petites feuilles [Haiti]; mukusao, umusasa [Congo]; native birch, native lignum vitae [Tasmania]; sanatha [Pakistan]; sanatta [Sanskrit]; switch sorrel [Jamaica]; vassoura vermelha [Brazil]; vrali [Spain]; walaytinahndi [Hindi]; yxichapulin [Aztec].
To list the many uses of this plant around the world would be a huge task. However, Kew’s Survey of Economic Plants for Arid and Semi-Arid Lands (SEPASAL) has undertaken a comprehensive collation of uses recorded in available scientific literature. In the western part of the island of New Guinea, for example, Yali highlanders use the wood for house construction and firewood, and apply heated leaves as plasters for wounds. D. viscosa is also used for house construction elsewhere in Southeast Asia, West Africa and Brazil.
Hopwood is also used in New Guinea for making tools and fish traps, for stimulating lactation in mothers, as incense for funerals, and as a remedy for dysentery. Various parts of the plant are used traditionally in Africa and Asia for treating digestive system disorders, infections, rheumatism, respiratory complaints and skin problems. Early settlers in Australia used D. viscosa as a substitute for hops for brewing beer (as reflected in some of common names of this plant), a use also recorded from Iraq. Hopwood leaves have been reported to be chewed as a stimulant in some parts of the world (such as in Colombia and Peru, where the leaves are sometimes mixed with coca, Erythroxylum coca).
Dodonaea viscosa readily colonizes open areas and secondary forest, and is tolerant of salinity, drought and pollution. It is therefore useful for dune stabilization, restoring degraded lands and for reforestation. Its fast growth and tolerance of strong winds make it an excellent hedge and windbreak, and it is planted as a decorative shrub (e.g. in South Africa, Australia and southern U.S.A.).
Millennium Seed Bank: Seed storage
Kew's Millennium Seed Bank Partnership aims to save plant life world wide, focusing on plants under threat and those of most use in the future. Seeds are dried, packaged and stored at a sub-zero temperature in our seed bank vault.
Description of seeds: Black, 2-3 mm in length and firm when ripe, contained in three- or four-winged capsules that become brittle when mature.
Number of seed collections stored in the Millennium Seed Bank: 20.
Seed storage behaviour: Orthodox (the seeds of this plant survive being dried without significantly reducing their viability, and are therefore amenable to long-term frozen storage such as at the MSB)
Germination testing: 100% germination when chipped with scalpel (on 1% agar, at 15, 20 and 25 oC, 8/16). 49-67% germination (pre-sowing treatment = 80% sulphuric acid for 4 minutes) on 1% agar under range of temperature & lighting conditions.
Composition values: 7.6-19% oil content (entire seed/nut). 20.4-21.4% protein content (entire seed/nut).
Hopbush is cultivated in the Tropical Nursery, one of the behind-the-scenes areas of Kew. It is grown from seed; some sources recommend pre-treatment of the seed in very hot water. Kew’s general potting mix is used, which consists of coir and Silvafibre, with screened loam, Osmacote and Kieserite. Alternatively, a light, well-drained soil could be used.
Hopbush can also be propagated by taking cuttings; this method can be used to obtain female plants for the aesthetic value of their winged fruits. At Kew, hopbush is grown in a glasshouse zone where the minimum temperature is 16˚C, and is kept under natural light. Hopbush will tolerate lengthy dry periods and does not require heavy feeding. Occasional mealy bug and whitefly infestations are dealt with using biological controls and, if necessary, by chemical sprays.
Hopbush at Kew
Hopbush is cultivated in the Tropical Nursery, one of the behind-the-scenes areas of Kew.
Dried and alcohol-preserved specimens of hopbush are held in the Herbarium, and details of some of these specimens can be seen in the online Herbarium Catalogue.
Specimens of hopbush are also held in the Economic Botany Collection.
South Africa Landscape - Kew at the British Museum
Between April and October 2010, Kew and the British Museum brought a small corner of South Africa to the heart of London. The South Africa Landscape celebrated a shared vision to strengthen cultural understanding and support biodiversity conservation across the world.
Dodonaea viscosa (hopbush) was one of the star plants featured in the Landscape.
Australian Native Plants Society (Australia) - Dodonaea viscosa. Available online.
Closs, J. & West, J. (1993). Dodonaea – The Hop Bush. Australian Plants 137.
Images: © J.R.I. Wood, Darwin Initiative Project 161/11/015.
Milliken, W. (1999). Ethnobotany of the Yali of West Papua. Royal Botanic Garden Edinburgh electronic publication. Available online.
Prendergast, H.D.V. & Pearman, G. (2001). Comparing uses and collections - the example of Dodonaea viscosa Jacq. [Sapindaceae]. Economic Botany 55: 184-186.
Kew Science Editor: William Milliken
Kew contributors: Steve Davis (Sustainable Uses Group), James Beattie
Copyediting: Emma Tredwell
While every effort has been taken to ensure that the information contained in these pages is reliable and complete, the notes on hazards, edibility and suchlike included here are recorded information and do not constitute recommendations. No responsibility will be taken for readers’ own actions.