Tropical Soda Apple  is an aggressive prickly perennial shrub one metre to two metres high.

It is a native of north-eastern Argentina, south-eastern Brazil, Paraguay and Uruguay.

An upright much branching perennial shrub, it has broad-based, straight, cream-coloured prickles to 12 mm long scattered on most plant parts.

Leaves are mostly 10-20 cm long and 6-15 cm wide. The upper and lower leaf surfaces are densely covered in short hairs; mid-veins and primary lateral-veins are cream coloured on both sides of the leaves.

Flowers are white, with five petals 2-4 mm long. They occur in clusters of three to six, off a short stem.

Mature fruit are yellow and golf-ball size (20-30 mm in diameter). When immature they are pale green with dark green veins, like immature water melons.

Tropical Soda Apple reproduces by seed and can regenerate from root material.

In NSW cattle movement is likely to be the major vector of spread.

The occurrence of the weed near saleyards (Casino) in NSW supports this theory.

However, seed can also be spread by feral animals and birds that feed on the fruit, and via water and contaminated produce, soil and equipment.

Tropical soda apple invades open to semi-shaded areas, including pastures, forests, riparian zones, roadsides, recreational areas, horticultural areas and cropping areas.

It reduces biodiversity in natural areas by displacing native plants and disrupting ecological processes.

Its foliage is unpalatable to livestock, thus reducing carrying capacity.

Prickles on this plant restrict native animal and stock grazing and can create a physical barrier to animals, preventing movement to shade and water.

The plant is a host for many diseases and pests of cultivated crops and it contains solasodine, which is poisonous to humans.

Tropical Soda Apple was first identified in Australia in the Kempsey area, on the Mid North Coast of New South Wales in August 2010.

However, this weed is believed to have been present in this area for a number of years.

The current extent of that infestation is about 50 ha.

Subsequent surveys have identified other smaller infestations in surrounding areas, including Wingham, Casino and Grafton.

In Australia it has the potential to spread in coastal regions of NSW and Queensland.