Jerusalem thorn; It is also known as Barbados flower-fence, horse bean, jelly bean tree, or parkinsonia.

Parkinsonia aculeata. It was known previously as Mimosa bimocronata. It is a member of the Fabaceae.

Africa, Asia, North, South and Central America, the Caribbean, Europe, Oceania. It is recorded from Australia, Federated States of Micronesia, Guam, and New Caledonia.

It is native to southern North America, northern Mexico, the Galapagos Islands and northern South America.

An important weed in some Pacific island countries. Invasive in hot regions (sub-humid and arid), and has become naturalised and weedy everywhere, whether native or introduced. Jerusalem thorn is mostly found growing near creeks, rivers, bores and dams in semi-arid regions (especially those with a distinctive wet and dry season). It also colonises grasslands, open woodlands, rangelands, pastures, waste areas, disturbed sites and roadsides. It can grow up to1500 masl. Its invasive weediness is related to the production of  large amounts of seeds and ability to tolerate a wide range of soils, including those seasonally flooded.

Jerusalem thorn is an upright spiny shrub or small tree often forming dense thickets. It can grow to 8 m, but more commonly is between 2-6 m (Photo 1). It can be single or multi-stemmed. The smooth, green stems are slender and tend to droop and zig-zag (Photo 2). Young stems have a pair of spines, 3-20 mm long, below each leaf. Leaves with flat, green, leaf stalk, up to 30 cm long and 2–3 mm wide, with numerous small, 4–10 mm, green, oblong leaflets staggered along both sides (Photos 3&4).

Flowers about 20 mm across with four yellow petals and one erect orange or orange-spotted petal (Photos 5&6). Seed pods, 30–130 mm long, straight with bulges around seeds and points on both ends; they are straw-brown when ripe. Generally, pods contain 1-4 seeds, but occasionally up to 11. Seeds are olive-green to brown and oblong, 10 mm by 4 mm. The roots are mostly shallow.

Jerusalem thorn reproduces mainly by seed, but can also produce suckers (particularly after it has been damaged). The seeds are spread by birds and other animals, especially cattle, and seed pods float in water and can be carried from upper catchment areas downstream. Also carried long distances in mud on animals and vehicles. One tree can produce more than 5000 seeds per year.

A serious pest in many countries. It is one of Australia's worse weeds, and is a problem in tropical Africa, Hawaii and other Pacific island countries. Impacts are both environmental and economic. Effects upon livestock grazing are considerable in Australia due to competition with forage grasses, blocking access to water sources, damage to hooves and the consequences from infected sores. Thickets of the tree are also home to feral animals, pigs in particular. Detailed economic assessments are lacking.

Often introduced as a fodder tree, for hedging, shade, wind-breaks or as an ornamental able to tolerate dry and saline sites and waterlogging. Seeds are rich in protein and are eaten. Medicinal properties are reported.