Solanum plastisexum is a species of bush tomato from the Australian monsoon tropics that exhibits "breeding system fluidity" – that is, it has no stable sexual expression.

The species is restricted to a small area in the central region of the Northern Territory of Australia on and around the Buchanan Highway.

It confounded field botanists since at least the early 1970s because it does not conform to any one floral form and/or inflorescence type.

[1] The describers commented that Solanum plastisexum is "a new species that serves as an example of for the diversity of sexual/reproductive form that has been increasingly recognised amongst plants – it is also evidence that attempts to recognise a “normative” sexual condition amongst the planet's living creatures is problematic.

When considering the scope of life on Earth, the notion of a constant sexual binary consisting of distinct and disconnected forms is, fundamentally, a fallacy.