On the basis of morphological data presented herein, Plectrachne Henr,
is included in Triodia R.Br. This congeneric change requires 15 new c
ombinations and three new nominations. In Triodia R.Br. sens. lat., 11
new species are proposed, one subspecies is raised to specific rank,
while three species and six varieties are reduced to synonyms. For the
first time, Triodia melvillei and T. schinzii are recorded for South
Australia, T. bunicola for Victoria, T. mollis for Queensland and T. m
arginata for New South Wales. Although probably monophyletic, Triodia
as here interpreted is widely variable. Thus, a classification of nine
informal infrageneric groups is proposed.