Ptilotus unguiculatus

Ptilotus unguiculatus
Holotype specimen of Ptilotus unguiculatus. Insert: Close-up of an inflorescence.

A new species of Ptilotus (Amaranthaceae) has recently been described and name Ptilotus unguiculatus T.Hammer. The species is known from a collection in 1970 on Edaggee Station, SSE of Carnarvon, Western Australia.

The species is an annual herb with conspicuously clawed whitish-green sepals, for which it is named unguiculatus (‘having claws’).

Hammer, T.A. 2018. The Ptilotus murrayi species group: synonymisation of P. petiolatus under P. murrayi and description of the new Western Australian species P. unguiculatus (Amaranthaceae). Swainsona 31(6): 93–100.

New Ptilotus species from the Gascoyne

A new species of Ptilotus (Amaranthaceae) has been described in Volume 29 of Nuytsia. The new species, Ptilotus yapukaratja R.W.Davis & T.Hammer, is a shrub with succulent leaves and pink flowers (pictured) that occurs near Lorna Glen Station (Matuwa) in the Gascoyne bioregion of Western Australia. The specific epithet was proposed by the Elders from the Tarlka Matuwa Piarku Aboriginal Corporation, the traditional custodians of the Matuwa Kurrara Kurrara Indigenous Protected Area and is derived from their words yapu (rock) and karatja (belonging to), referring to the rocky habitat on which it is found. The species is rare and listed as Priority One under Conservation Codes for Western Australian Flora. Further information can be found in the publication:

Davis, R.W. & Hammer, T.A. (2018) Ptilotus yapukaratja (Amaranthaceae), a new and rare species from the Gascoyne bioregion of Western Australia. Nuytsia 29: 157–160. [pdf]

Ptilotus actinocladus

Ptilotus actinocladus
The new species, Ptilotus actinocladus T.Hammer & R.W.Davis. Photo by G. Byne.

A new and rare species, Ptilotus actinocladus T.Hammer & R.W.Davis, has been recently published in volume 29 of the journal Nuytsia (Hammer & Davis, 2018). The new species is endemic to the Gascoyne bioregion of Western Australia and known from several collections, mostly around Doolgunna Station.

Ptilotus pseudohelipteroides
Ptilotus pseudohelipteroides Benl in South Australia. Photo by T. Hammer.

Specimens currently within P. actinocladus were previously assigned to P. pseudohelipteroides Benl, constituting the only specimens of this species from Western Australia. The type of P. pseudohelipteroides is from Queensland, with the typical variety of this species occurring in the Northern Territory, Queensland and South Australia. Ptilotus pseudohelipteroides was described by Gerhard Benl (1959), based on the variety Trichinium helipteroides F.Muell. var. minor J.M.Black described by John M. Black (1924) and latter the combination made within Ptilotus by Hansjörg Eichler (as P. helipteroides var. minor). Benl separated P. pseudohelipteroides from P. helipteroides (F.Muell.) F.Muell. based on it varying in floral and vegetative characters.

Ptilotus actinocladus map
Map the distribution of Ptilotus actinocladus (triangles), P. helipteroides (vertical shading) and P. pseudohelipteroides (horizontal shading).

When examining the specimens from Western Australia for the identification key to the Ptilotus (available on KeyBase), it was clear that these were different from P. pseudohelipteroides. The morphological variation and geographical disjunction between the two entities clearly showed that the specimens from Western Australia deserve to be placed within its own species. The new species does overlap with P. helipteroides, but is also morhologically distinct from that species in multiple floral and vegetative characters, including the habit, leaf and stem indumentum, and size of the floral parts (which are more similar to P. pseudohelipteroides). The specific epithet of the new species refers to the radiating (actino-) stems (cladus) that are prostrate and characteristic of this species. Please feel free to read it in more detail on FloraBase, at

  • Benl, G. (1959). New species and varieties of Ptilotus R.Br. (Amaranthaceae). Muelleria 1(2): 105–107.
  • Black, J.M. (1924). Casuarinaceae – Euphorbiaceae. Flora of South Australia 2: 212.
  • Eichler, Hj. (1965). Supplement to J.M.Black’s Flora of South Australia (Second Edition, 1943-1957): 130.
  • Hammer, T.A. & Davis, R.W. (2018). Ptilotus actinocladus (Amaranthaceae), a new and rare species from the Gascoyne bioregion, Western Australia. Nuytsia 29: 145–149. (pdf)

The showy and the shy

Ptilotus gaudichaudii
Fig. 1. An inflorescence of Ptilotus gaudichaudii, showing open flowers. Photo by T. Hammer.

In my recent paper (Hammer et al., 2018), two species were reinstated from Ptilotus gaudichaudii (Steud.) J.M.Black (Amaranthaceae), Ptilotus eremita (S.Moore) T.Hammer & R.W.Davis and Ptilotus modestus T.Hammer. These species were previously included as subspecies under P. gaudichaudii, namely subspp. parviflorus (Benth.) Lally and eremita (S.Moore) Lally. The paper includes the taxonomic and nomenclatural histories of the species, including the justification for raising them to species rank.

This study was spurred by observations made in the field, particularly the species P. eremita and P. gaudichaudii, which overlap significantly in their distributions and were found co-occurring at several sites without any intermediates. The species boundaries within this group was assessed by examining the morphology of specimens from throughout their ranges.

Ptilotus eremita
Fig. 2. An inflorescence of Ptilotus eremita, showing an open flower (centre). Photo by T. Hammer.

Ptilotus gaudichaudii can be reliably discriminated from the other two species by having larger tepals (technically sepals), style, staminal filaments and anthers and having widely-gaping showy flowers (Fig. 1). Ptilotus eremita by comparison has flowers which do not gape widely after anthesis, and instead form a tube down to to the ovary (Fig. 2). The small stamens crowd the pistil and do not orientate themselves in the way observed for P. gaudichaudii. Ptilotus modestus is most similar to P. eremita, but the latter varies from the former by having a slightly longer style and staminal filaments and having three fertile stamens (as opposed to four) and occurring in central and eastern Australia (as opposed to Western Australia). Read more about this study here:

Hammer, T.A., Davis, R.W. & Thiele, K.R. (2018). The showy and the shy: reinstatement of two species from Ptilotus gaudichaudii (Amaranthaceae). Australian Systematic Botany 31: 1–7.

Ptilotus benlii

Ptilotus benlii
Flowering inflorescences of Ptilotus benlii. Photo by R. Davis.

Ptilotus benlii R.W.Davis & T.Hammer was recently described in the journal Nuytsia as a new species for Western Australia (Davis & Hammer, 2017). It is a perennial herb found from south of Kalbarri to north of Merridin, WA.

Ptilotus benlii is closely related to P. calostachyus F.Muell., P. drummondii (Moq.) F.Muell., P. aphyllus Benl and P. schwartzii (F.Muell.) Tate. It shares the character with these species of possessing staminal cup appendages, but can be easily differentiated by its larger, green-white flowering spikes and bright pink filaments and stamens. Ptilotus benlii is also quite close to the southwestern species P. esquamatus (Benth.) F.Muell., with which it differs in that the latter lacks staminal cup appendages and has much smaller inflorescences of pinkish flowers and a decumbent habit.

Ptilotus benlii
The habit of Ptilotus benlii. Photo by R. Davis.

The species was named in honour of German botanist Gerhard Benl (1910–2001), who contributed significantly to the taxonomy of Ptilotus throughout his career, naming upwards of 30 species and various infraspecific taxa.

Davis, R.W. & Hammer, T.A. (2017). Ptilotus benlii (Amaranthaceae), a new species from Western Australia. Nuytsia 28: 299–302.