Slime moulds have a reproductive stage that looks very similar to fungi. Because of this they were originally classified in the Kingdom of Fungi, but are now considered Protozoa.

There is still an ongoing debate about the classifcation of the different types of slime moulds. Scientists are currently trying to understand the relationships among the three groups:

• Myxomycetes – the plasmodial slime moulds;
• Dictyosteliida – the cellular slime moulds; and
• Protostelids – the spore producing amoebas.

The division of Myxomycetes are the only macroscopic slime moulds - that is, visible to the naked eye. Most slime moulds are quite small, only a few centimeters across, but some species may reach sizes of up to several square meters.

Slime moulds have a very interesting and complicated life cycle. A young slime mould resembles and behaves much like an amoeba - which is a single-celled animal! The slime mould cell moves about, feeding on the bacteria, yeasts and fungi that live in dead plant material. In gardens, this is commonly a substrate such as wood mulch or leaf litter. When a slime mould cell grows to a certain size, it will divide in two. This process continues until there are many thousands of individual slime mould cells crawling over the substrate.

If the food should run out, something strange happens. A chemical signal is secreted and the slime mould cells congregate into a united mass. It then begins moving as a single organism in search of a new food source. This is the familiar gelatinous "slime" stage that gives them the slime moulds common name.

It is in this state that the organism can enter its reproductive stage. Individual cells change their shape to become the organism's fruiting bodies, tiny stalks which release microscopic spores into the air. These spores, in turn, hatch into the young amoeba-like slime mould cells and the cycle begins again.

Girraween has only the one species of slime mould discovered thus far – Fuligo septica, pictured below.