Recognition of the genus Thaumatophyllum Schott - formerly Philodendron subg. Meconostigma (Araceae) - based on molecular and morphological evidence Author Sakuragui, Cassia Monica Universidade Federal do Rio de Janeiro, Centro de Ciencias da Saude, Instituto de Biologia, Departamento de Botanica, Av. Carlos Chagas Filho, 373 - Sala A 1 - 088 - Bloco A, Ilha do Fundao, Rio de Janeiro, RJ, CEP 21941 - 902, Brazil cmsakura12@gmail.com Author Calazans, Luana Silva Braucks https://orcid.org/0000-0002-3308-3725 Universidade Federal do Rio de Janeiro, Centro de Ciencias da Saude, Instituto de Biologia, Departamento de Botanica, Av. Carlos Chagas Filho, 373 - Sala A 1 - 088 - Bloco A, Ilha do Fundao, Rio de Janeiro, RJ, CEP 21941 - 902, Brazil Author Oliveira, Leticia Loss de Universidade do Estado do Rio de Janeiro, Centro de Educacao e Humanidades, Instituto de Aplicacao Fernando Rodrigues da Silveira, Rua Santa Alexandrina, 288, Rio Comprido, Rio de Janeiro, RJ, CEP 20261 - 232, Brazil Author Morais, Erica Barroso de University of Zurich, Department of Systematic and Evolutionary Botany, 8008 Zurich, Switzerland Author Benko-Iseppon, Ana Maria Universidade Federal de Pernambuco, Centro de Biociencias / Genetica, Av. Prof. Moraes Rego, 1235, Recife, PE, CEP 50670 - 420, Brazil Author Vasconcelos, Santelmo Instituto Tecnologico Vale, Rua Boaventura da Silva, 955, Nazare, Belem, PA, CEP 66055 - 090, Brazil Author Schrago, Carlos Eduardo Guerra Universidade Federal do Rio de Janeiro, CCS, Instituto de Biologia, Departamento de Genetica, Av. Carlos Chagas Filho, 373 - Sala A 2 - 092 - Bloco A, Ilha do Fundao, Rio de Janeiro, RJ, CEP 21941 - 902, Brazil Author Mayo, Simon Joseph Royal Botanic Gardens, Kew, Richmond, Surrey, TW 9 3 AB, UK text PhytoKeys 2018 2018-05-02 98 51 71 http://dx.doi.org/10.3897/phytokeys.98.25044 journal article http://dx.doi.org/10.3897/phytokeys.98.25044 1314-2003-98-51 FF8F8C39FFFC333AA91B9B43FF94FFBA 1244349 Thaumatophyllum petraeum (Chodat & Vischer) Sakur., Calazans & Mayo comb. nov. Fig. 4. Philodendron petraeum Chodat & Vischer, Bull. Soc. Bot. Geneve 11: 296. 1919 publ. 1920. Philodendron petraeum Type. Paraguay, Tobaty between Tobaty and Barrero Grande, R.H. Chodat & W. Vischer 349 (holotype: G). Philodendron petraeum Philodendron petraeum var. triangulare Chodat & Vischer, Bull. Soc. Bot. Geneve 11: 299. 1919 publ. 1920. Philodendron petraeum Type. Paraguay, Tobaty between Tobaty and Barrero Grande, R.H. Chodat & W. Vischer 347 (holotype: G). Philodendron petraeum var. valenzuelae Chodat & Vischer, Bull. Soc. Bot. Geneve 11: 299. 1919 publ. 1920. Philodendron petraeum Type. Paraguay, prope Valenzuela, R. H. Chodat & W. Vischer 357 (holotype: G). Remarks. The species was previously synonymised under P. tweedieanum (= T. tweedieanum ) by Croat and Mount (1988) . We propose its reinstatement as an accepted species based on the following morphological differences: herbs erect and rupiculous (x herbs decumbent or rhizomatous subterranean acaulous in T. tweedieanum ), prophyll deciduous when still herbaceous (x marcescent and persistent-membranous in T. tweedieanum ), denudation of posterior division absent (x present in T. tweedieanum ), presence of stylar central dome in pistillate flowers (x absence of stylar central dome in T. tweedieanum ). Besides having a different gynoecium type ( Calazans et al. 2014 ), the majority-rule consensus tree based on morphological characters support these species as different lineages. Furthermore, the phylogeny based on molecular characters supports the two species as separate taxa ( Loss-Oliveira et al. 2014 ). Thaumatophyllum petraeum was first described for Paraguay with four varieties and are still recorded only from this country. We have no evidence to recognise the varieties as distinct taxa, except for. P. petraeum var. tobatiense Chodat & Vischer, which is a synonymous of P. undulatum (= T. undulatum ). Figure 4. Thaumathophyllum petreum . A Habit B Longitudinal cut of the inflorescence C Staminode D Stamen E Longitudinal cut of a female flower F Transversal cut of a female flower showing the 6-locular ovary G Side view of a female flower H Infructescence. All from Calazans & Morais 28 (RB).