Two new Australian species and a new combination in Muehlenbeckia (Polygonaceae)

Two new species of Muehlenbeckia Meisn. are described, and a key is provided to these and similar species in eastern Australia. Muehlenbeckia arnhemica K.L.Wilson & R.O.Makinson grows on rocky outcrops in the northern tropical part of the Northern Territory. Muehlenbeckia costata K.L.Wilson & R.O.Makinson is restricted to rocky outcrops in ranges in southeastern Queensland and northern New South Wales. A new combination is made for M. stenophylla F.Muell. as a subspecies of M. diclina (F.Muell.) F.Muell., and lectotypes are selected for these two names.