Pom Poms

Ptilotus manglesii habit
The habit of Ptilotus manglesii near Bindoon in Western Australia. Photo by T. Hammer.

Ptilotus manglesii (Lindl.) F.Muell. (commonly called mulla mulla or pom poms) is a perennial herb endemic to the south-west of Western Australia and common in the hills around Perth, typically occurring in Eucalyptus woodlands and forests. It was described as Trichinium manglesii by John Lindley in Edwards’ botanical register in 1839 from “Swan River Colony” (probably near present-day Perth). It was later transferred to Ptilotus R.Br. by Mueller (1868). The species was named for Captain James Mangles of the Royal Navy, who was interested in botany and horticulture in colonial Western Australia and had collected plant specimens for Lindley.

Ptilotus manglesii
An inflorescence of Ptilotus manglesii (Lindl.) F.Muell. Photo by T. Hammer

Ptilotus manglesii has been found to be closely related to P. nobilisP. exaltatus species group on the molecular phylogeny of the genus (Hammer et al., 2015). Ptilotus exaltatus overlaps slightly in distribution with P. manglesii around Geraldton, Western Australia. It can be easily distinguished from P. exaltatus by its perennial, decumbent habit, as well as multiple floral characters. Two phrase-names at the Western Australian Herbarium, Ptilotus sp. Beaufort River (G.J. Keighery 16554) and Ptilotus sp. Porongurup (R. Davis 10805), that are morphologically similar to P. manglesii are currently being investigated as putative new species. More to come about these two!

References:
– Hammer, T., Davis, R. & Thiele, K. (2015). A molecular framework phylogeny for Ptilotus (Amaranthaceae): Evidence for the rapid diversification of an arid Australian genus. Taxon 64(2): 272–285. http://dx.doi.org/10.12705/642.6
– Mueller, F.J.H von (1868). Fragmenta Phytographiae Australiae. Vol. 6, p. 230. (Government Printer: Melbourne) http://dx.doi.org/10.5962/bhl.title.287