Ptilotus macrocephalus (commonly as featherheads, green mulla mulla or green pussytails) is a native Australian perennial herb growing up to 50cm (20inches) high.[1] The species was originally described as Trichinium macrocephalum by Robert Brown in 1810 based on specimens from Victoria, Australia.[2] In 1816, it was first transferred to the genus Ptilotus by Jean Louis Marie Poiret.[3] While once considered distributed throughout most of the Australian mainland, current research limits the distribution of P. macrocephalus to south-eastern Australia, mostly in south-eastern South Australia, Victoria and New South Wales. A study by Hammer et al. (2019) determined that specimens previously identified as P. macrocephalus are morphologically and ecologically distinct species, the now named Ptilotus xerophilus T.Hammer & R.W.Davis (arid central and western Australia) and Ptilotus psilorhachis T.Hammer & R.W.Davis (eastern Queensland).
P. macrocephalus has cream-green coloured ovoid flower heads. As with other green-flowered Ptilotus species (e.g. Ptilotus nobilis), they are thought to be predominantly pollinated by nocturnal moths.