Acrasis has long been considered as a cellular slime mould, because it grows as single amoeboid cells which then aggregate to form multicellular fruiting structures. However it differs from other slime moulds in many respects, including the size of individual cells (much larger), the way they move (much faster by extending large lobopodia), and the way they form fruiting bodies (perhaps no chemotaxis). Sequence analysis of some genes support its remote kinship with the dictyostelid slime moulds. The genus Acrasis, along with some related genera, are now more commonly classified in protozoans.
The fruiting body looks like a tree, or because of its pink colour, a coral (photo). It is sort of clustered chains of spores, or cysts, so each cell in the trunk of the fruiting body germinates as well to give rise to an amoeboid cell.