Snakewood Mistletoe (Amyema xiphophylla: Loranthaceae), a distinctive new species from Western Australia’s arid zone

Amyema Tiegh. (Loranthaceae) is a genus of aerial hemiparasites that grow on the branches of host plants, obtaining water and nutrients from their host via a specialised vascular connection (an haustorium) while producing some of their own carbohydrates by photosynthesis (Lamont & Southall 1982; Lamont 1983; Pate 1995). Of the 40 species currently recorded in Australia, 23 occur in Western Australia (Western Australian Herbarium 1998–; Council of Heads of Australasian Herbaria 2006–) including the new species described below, which has only been recorded growing on Acacia xiphophylla E.Pritz. (Snakewood). This in itself is unusual: relatively few species of Amyema occur on only one species of host, although some are host specific at a regional level (Start 2015) and many have a narrow range of host species or are restricted to a particular genus (Barlow 1984; Downey 1998; Start 2011, 2013, 2015). The only other species in Loranthaceae that have been recorded on Snakewood are Lysiana casuarinae (Miq.) Tiegh. s. lat. (Downey 1998: A.A. Mitchell 4730, PERTH 05096103; B. Backhouse et al. BEM 223, PERTH 05465591) and L. murrayi (F.Muell. & Tate) Tiegh. (S. van Leeuwen 5045, PERTH 07615418).