Molecular data support Orianthera: a new genus of Australian Loganiaceae

Abstract

Results from recent molecular systematics have indicated that Logania R.Br. in its current circumscription is polyphyletic, with each of its two constituent sections, Logania sect. Logania and L. sect. Stomandra, representing distinct monophyletic clades. Logania sect. Stomandra is here raised to generic status as Orianthera C.S.P.Foster & B.J.Conn since the name Stomandra has already been applied to a genus in Rubiaceae. Orianthera differs from Logania sensu stricto based on the place of insertion of the stamens (in the sinus between the corolla lobes in Orianthera; in the middle of the corolla tube in Logania); the anthers being exserted from the corolla mouth in Orianthera (anthers included in Logania); the shape of the apex of each calyx lobe (acute to tapering, with membranous margin in Orianthera; obtuse in Logania, without membranous margin); and the sexuality of flowers (bisexual in Orianthera; unisexual in Logania). A key to genera in the tribe Loganieae is provided and 13 species (all new combinations) are enumerated for Orianthera.