Circumscription ofMarsdenia (Asclepiadaceae: Marsdenieae), with a revision of the genus in Australia and Papuasia*

Abstract

The genus Marsdenia R.Br. is circumscribed utilising data from taxonomic history and morphology. and its relationship to other genera in the Marsdenieae is discussed. Genera that have usually been or commonly regarded as distinct. i.e. Gymnenla R.Br., Leichardtia R.Br., Bidaria (Endl.) Decne. and Thozetia F . Muell . ex Benth., are discussed and considered congeneric with Marsdenia. A revision of the Australian and Papuasian (Irian Jaya, Papua New Guinea, Solomon Islands) taxa of Marsdenia is presented and 78 species (one with two subspecies) and one putative interspecific hybrid are recognised. Forty-six taxa are accepted as new, namely Marsdenia ambuntiensis, M. archboldiana, M. argillicola, M . arfakensis, M. Belensis, bilobata, bliriensis, M. Brassii, M. Brevis, M. Brunnea, M. carrii, M. connivens, M. cremea, M. destituta, M. dischidioides, M. divisicola, M. egregia, M. jlavida, M. globosa, M. grandis, M. graniticola, M. hamata, M. kebarensis, M. lacicola, M. longipedicellata, M. millariae, M. mira, M. paludicola, M. papillosa, M. parva, M. poioensis, M. primulina, M. pumila, M. quadrata, M. rara, M. spathulata, M. straminea, M. subglobosa, M. torsiva, M. trilobata, M. tumida, M. urniflora, M. variabilis, M. venusta, M. viridiflora subsp. tropica and M. volcanica. A new name, M. angustata, is provided to replace Bidaria erecta F.Muell. New combinations made are M. brevifolia (Gymnema brevifolium Benth.), M. geminata (Gymnema geminata R.Br.), M. micradenia (Gymnema micradenium Benth.), M. muelleri (Gymnema muelleri Benth.), M. pleiadenia (Gymnema pleiadenia F.Muell.), M. rivularis (Gymnema rivular Schltr.), M. suborbicularis (Gymnema suborbiculare KSchum.), M. tricholepis (Gymnema tricholepis Schltr.) and M. trinewis (Gymnema triverve R.Br.). Lectotypes are chosen for a number of names. A putative hybrid is recorded between M. viridiflora subsp. viridiflora and M. microlepis. Separate keys to the Australian and Papuasian species of Marsdenia are given. Separate keys to the Australian and Papuasian genera of Asclepiadaceae are given.

* Christensen research Institute Contribution No . 114.