Observations on the rare triggerplant Stylidium coroniforme (Stylidiaceae) and the description of two allied taxa of conservation concern

Stylidium amabile Wege & Coates, a new, rare triggerplant from near Maya in south-west Western Australia, is described and illustrated. This new species has morphological affinity to the rare Wongan Hills triggerplant S. coroniforme F.L.Erickson & J.H.Willis, but has a distinct stigma, a different pattern of corolla markings and is genetically distinct. A revised description of S. coroniforme is provided and S. coroniforme subsp. amblyphyllum Wege, a new infraspecific taxon with distinctive leaves and a distribution near Quairading, is recognised. These three taxa are among the most geographically restricted within the triggerplant genus and all are vulnerable to local extinction.