Gastrolobium bilobum, commonly known as heart-leaved poison, is a bushy shrub which is endemic to south west Western Australia. The species is a member of the family Fabaceae and is probably the most toxic species in the genus Gastrolobium, containing high levels of monofluoroacetic acid. The species grows to a height of up to 4 metres. Between late winter and early summer (August to December in Australia) it produces yellow-orange pea-flowers with a central yellow area encircled by a band of red, and a maroon keel. The leaves are cuneiform, obovate or elliptic.