A revision of Commersonia including Rulingia (Malvaceae s.l. or Byttneriaceae)

A taxonomic revision and DNA sequence analysis of all species previously attributed to Rulingia R.Br. and Commersonia J.R.Forst. & G.Forst. resulted in two major groupings, referred to a redefined Commersonia and a new genus (Androcalva C.F.Wilkins & Whitlock 2011). In total, 25 species are now recognised within Commersonia, including the type species of Rulingia, and 14 species previously included in Rulingia and 10 in Commersonia. Three of these are described as new (C. apella C.F.Wilkins, C. erythrogyna C.F.Wilkins and C. gilva C.F.Wilkins). A new subspecies, C. magniflora subsp. oblongifolia C.F.Wilkins, is recognised and C. bartramia (L.) Merr. var. tahitensis Dorr is raised to species level as C. tahitensis (Dorr) C.F.Wilkins & Whitlock. Two new combinations are made, Rulingia platycalyx Benth. and R. parviflora Endl. as C. parviflora (Endl.) C.F.Wilkins & Whitlock; and R. cistifolia Steetz and R. rugosa Steetz as C. rugosa (Steetz) F.Muell. The redefined Commersonia is monophyletic and characterised by anthers with sublatrorse dehiscence and mainly hairy staminodes, compared with extrorse dehiscence and glabrous staminodes as seen in Androcalva