Nomenclatural changes in Coleus and Plectranthus (Lamiaceae): a tale of more than two genera Alan Paton, Montfort Mwanyambo, Rafaël H.A. Govaerts, Kokkaraniyil Smitha, Somran Suddee, Peter Phillipson, Trevor Wilson, Paul Forster, Alastair Culham To cite this version: Alan Paton, Montfort Mwanyambo, Rafaël H.A. Govaerts, Kokkaraniyil Smitha, Somran Suddee, et al.. Nomenclatural changes in Coleus and Plectranthus (Lamiaceae): a tale of more than two genera. PhytoKeys, Pensoft, 2019, 129, pp.1-158. 10.3897/phytokeys.129.34988. hal-02297866 HAL Id: hal-02297866 https://hal.sorbonne-universite.fr/hal-02297866 Submitted on 26 Sep 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. A peer-reviewed open-access journal PhytoKeys 129:Nomenclatural 1–158 (2019) changes in Coleus and Plectranthus: a tale of more than two genera 1 doi: 10.3897/phytokeys.129.34988 RESEARCH ARTICLE http://phytokeys.pensoft.net Launched to accelerate biodiversity research Nomenclatural changes in Coleus and Plectranthus (Lamiaceae): a tale of more than two genera Alan J. Paton1, Montfort Mwanyambo2, Rafaël H.A. Govaerts1, Kokkaraniyil Smitha3, Somran Suddee4, Peter B. Phillipson5, Trevor C. Wilson6, Paul I. Forster7, Alastair Culham8 1 Science Directorate, Royal Botanic Gardens Kew, Richmond, Surrey,TW9 3AB, UK 2 National Herbarium and Botanic Gardens of Malawi, Zomba, Malawi 3 Department of Botany, University of Calicut, Kerala- 673 635, India 4 The Forest Herbarium (BKF), Department of National Parks, Wildlife and Plant Conservation, Chatuchack, Bangkok 10900,Thailand 5 Missouri Botanical Garden, P.O. Box 299, St. Louis, MO 63166, U.S.A. and Institut de Systématique, Evolution et Biodiversité (UMR 7205 –CNRS MNHN UPMC EPHE), Muséum national d’Histoire naturelle, Sorbonne Universités, C.P. 39, rue Cuvier 57, 75231 Paris CEDEX 05, France 6 National Herbarium of New South Wales, Royal Botanic Gardens & Domain Trust, Mrs Macquaries Road, Sydney, NSW 2000, Australia and School of Life and Environmental Sciences, Science Road, University of Sydney, NSW 2006, Australia 7 Queensland Herbarium, Department of Environment & Science, Brisbane Botanic Gardens, Mount Coot-tha Road, Toowong, Qld 4066, Australia 8 School of Biological Sciences, Uni- versity of Reading, Whiteknights, Reading, UK Corresponding author: Alan J. Paton ([email protected]) Academic editor: Eberhard Fischer | Received 29 March 2019 | Accepted 18 June 2019 | Published 23 August 2019 Citation: Paton AJ, Mwanyambo M, Govaerts RHA, Smitha K, Suddee S, Phillipson PB, Wilson TC, Forster PI, Culham A (2019) Nomenclatural changes in Coleus and Plectranthus (Lamiaceae): a tale of more than two genera. PhytoKeys 129: 1–158. https://doi.org/10.3897/phytokeys.129.34988 Abstract A synopsis of the genera Coleus Lour, Equilabium A.J.Paton, Mwany. & Culham and Plectranthus L’Hér. (Lamiaceae, Tribe Ocimeae, Subtribe Plecranthinae) is presented. Generic delimitation follows a recently pub- lished molecular phylogeny which identifiedColeus as the sister of the remaining genera of Subtribe Plectran- thinae; Plectranthus as sister to Tetradenia Benth. and Thorncroftia N.E.Br., and a separate phylogenetically distinct genus Equilabium comprising species previously placed in Plectranthus. In this treatment, 294 species of Coleus, 42 of Equilabium, and 72 of Plectranthus are recognized. All but one of the combinations in Equi- labium are new as only the genus and type species have been previously published. Two-hundred and twelve names are changed to combinations in Coleus from Plectranthus, Pycnostachys Hook. and Anisochilus Benth. Copyright Alan J. Paton et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. 2 Alan J. Paton et al. / PhytoKeys 129: 1–158 (2019) Keywords Anisochilus, Equilabium, generic delimitation, nomenclature, Ocimeae, Plectranthinae, Pycnostachys, Solenostemon Table of contents Introduction ............................................................................................................. 2 Taxonomic history .................................................................................................... 3 Methods ................................................................................................................... 5 Results and discussion .............................................................................................. 7 Taxonomic account .................................................................................................. 8 Subtribe Plectranthinae ........................................................................................ 9 Key to the genera of the Plectranthinae ................................................................ 9 Synopsis of genera and species of Coleus, Equilabium and Plectranthus.................... 10 Genus Coleus ...................................................................................................... 10 Genus Equilabium ............................................................................................ 111 Genus Plectranthus ........................................................................................... 127 Unplaced names ............................................................................................... 147 Excluded names ............................................................................................... 150 Acknowledgements ............................................................................................... 155 References ............................................................................................................ 156 Introduction Plectranthus L’Hér. is a widely used horticultural and medicinal plant genus (van Jaars- veld 2007, Lukhoba et al. 2006, Rice et al. 2011). It belongs in tribe Ocimeae, subtribe Plectranthinae, an Old World tropical group of around 450 species. Current taxonomic treatments generally follow Harley et al. (2004) by including the formerly recognized Coleus Lour. and Solenostemon Thonn. withinPlectranthus . However, within horticultural literature, Solenostemon is still frequently recognized (e.g. RHS (2017), Shepherd and Maybry (2016)). The commonly cultivated plant shown in Fig. 1 is thus variously known as Plectranthus scutellarioides (L.) R.Br or Solenostemon scutellarioides (L.) Codd., but “co- leus” is frequently used as a common name for this species, increasing the confusion. Recent phylogenetic work has shown that the circumscription of Plectranthus needs to be viewed in the context of related genera in Tribe Ocimeae, subtribe Plec- tranthinae. Paton et al. (2018) demonstrate that a clade containing the type of Coleus (C. amboinicus Lour. ≡ P. amboinicus (Lour.) Spreng.) is sister to the other genera of the Plectranthinae, and the type species of Plectranthus, P. fruticosus L’Hér., belongs in a clade which is sister to Thorncroftia N.E.Br and Tetradenia Benth. A further clade containing species that were previously placed in Plectranthus was recognized by Paton et al. (2018) as Equilabium Mwany., A.J.Paton & Culham (Fig. 2). The aim of this paper is to provide the necessary nomenclatural changes consistent with the recognition of Plectranthus, Coleus and Equilabium as distinct genera follow- ing phylogenetic results provided by Paton et al. (2018). Nomenclatural changes in Coleus and Plectranthus: a tale of more than two genera 3 Figure 1. A Display of cultivated Coleus scutellarioides (L.) Benth. in the Real Jardin Botánico, Madrid. B Close up of the cultivar ‘Campfire’, winner of the Royal Horticultural Society’s peoples choice award at Wisley 2017 (Photo: A.Paton). Taxonomic history Plectranthus was described by L’Héritier in 1788 (L’Héritier 1788) and Coleus by Loureiro in 1790 (de Loureiro 1790). In previous global reviews of the Lamiaceae, e.g. Bentham (1832, 1848, 1876) and Briquet (1897), Coleus was treated as distinct from Plectranthus by having the 4 stamens fused together rather than free to their base. Morton (1962) recognized that the character of the fused stamens was more plastic than previously thought and merged Coleus into Plectranthus, as first suggested by Brown (1810). However, Morton also placed weight on calyx characteristics leading him to recognize several genera based on calyx morphology including Solenostemon, Isodictyophorus A.Chev, Leocus A.Chev., Englerastrum Briq. and Neohyptis J.K.Morton. The merging ofColeus into Plectranthus has been followed by most authors since Morton’s account, for example, Keng (1978), covering Malesian species, Blake (1971, Australia), Codd (1985, southern Africa), Hedge et al. (1998, Madagascar), Suddee et al. (2004, Indochina), Forster (2011, Australia) and Paton et al. (2009, 2013, eastern and southern tropical Africa). Furthermore, although Codd (1985) and Morton (2006) also maintained Solenostemon, Keng (1978), Hedge et al. (1998) and subsequent