Marianthus bicolor is a low, erect, spreading shrub or climber with reddish purple new stems.

[2][3] This species was first formally described in 1839 by Alois (Aloys) Putterlick in Novarum Stirpium Decades.

[4][5] In 1860, Ferdinand von Mueller transferred the species to Marianthus as M. bicolor in his Fragmenta Phytographiae Australiae.

[7] Marianthus bicolor grows in mallee in valleys, on hills, flats, sandplains and roadsides, and is widespread in the south-west of Western Australia, mainly from the Darling Range to Ravensthorpe.

[2][3] Marianthus bicolor is listed as "not threatened" by the Government of Western Australia Department of Biodiversity, Conservation and Attractions.