An account of the reed triggerplants (Stylidium sect. Junceae: Stylidiaceae)
This taxonomic review of Stylidium sect. Junceae Mildbr. recognises eight species endemic to south-western Western Australia and presents a new circumscription for S. junceum R.Br., the original description of which was based on a mixed gathering comprising three distinct taxa. A lectotype is designated in order to fix the application of the name S. junceum to one of these, a species with a diminutive habit, pale creamy yellow to apricot-pink corolla lobes, and a column morphology that is unique within the genus. A neotype is designated for S. junceum subsp. brevius (E.Pritz.) Carlquist, which is not recognised as distinct. Stylidium scariosum DC. is reinstated and S. hesperium Wege, S. hygrophilum Wege, S. paludicola Wege and S. thryonides Wege described as new. Revised descriptions are provided for S. squamosotuberosum Carlquist and S. laciniatum C.A.Gardner, with S. junceum var. volubile F.Muell. lectotypified and placed into synonymy under the latter species. Descriptions, distribution maps, illustrations and photographs are supplied for each species, and an identification key provided. Stylidium hygrophilum has a highly localised distribution on the Blackwood Plateau south of Busselton and may warrant listing as Threatened. Stylidium paludicola, a species confined to swamps on the Swan Coastal Plain, is also listed as being of conservation concern, with targeted surveys required to better understand its conservation status.