Two new species of Acianthera (Orchidaceae) from the Brazilian Amazon
Abstract
Acianthera Scheidw. is a genus of Orchidaceae Juss. composed of approximately 300 species, nearly half of which occur in Brazil. To date, only eight species of the genus have been recorded from the Brazilian Amazon. A recent botanical excursion to Serra do Divisor National Park in the state of Acre, in the extreme western portion of the Brazilian Amazon, resulted in the discovery of two new species of Acianthera: A. amazonica Marcusso sp. nov. and A. nukiniana Marcusso sp. nov. Here, we describe these new species and present photographs, illustrations, taxonomic notes and comments on their morphological relationships, and environmental preferences. In addition we assign the conservation status and provide a geographic distribution map, as well as an identification key for Acianthera species from the Brazilian Amazon.
References
Bachman S., Moat J., Hill A.W., de la Torre J. & Scott B. 2011. Supporting Red List threat assessments with GeoCAT: geospatial conservation assessment tool. In: Smith V. & Penev L. (eds) e-Infrastructures for Data Publishing in Biodiversity Science. ZooKeys 150: 117–126. https://doi.org/10.3897/zookeys.150.2109
Beentje H. 2016. The Kew Plant Glossary: An Illustrated Dictionary of Plant Terms. 2nd ed. Royal Botanic Gardens, Kew, Richmond.
Campacci M.A. & Silva J.B.F. 2016. Acianthera saraca-taquerensis Campacci & J.B.F. Silva sp. nov. Coletânea de Orquídeas Brasileiras 12: 454–457.
Cardoso D., Särkinen T., Alexander S., Amorim A.M., Bittrich V., Celis M., Daly D.C., Fiaschi P., Funk V.A., Giacomin L.L., Goldenberg R., Heiden G., Iganci J., Kelloff C.L., Knapp S., Lima H.C., Machado A.F.P., Santos R.M., Mello-Silva R. & Forzza R.C. 2017. Amazon plant diversity revealed by a taxonomically verified species list. Proceedings of the National Academy of Sciences of The United States of America 114: 10695–10700. https://doi.org/10.1073/pnas.1706756114
Chiron G.R. & Bolsanello R.X. 2015. Orchidées du Brésil - As Orquídeas da Serra do Castelo (Espírito Santo - Brasil). 1st. Tropicalia, Voreppe.
Chiron G.R. & van den Berg C. 2012. Révision taxinomique du genre Acianthera (Orchidaceae, Pleurothallidinae). Richardiana 12: 59–77.
Correia C.S. 2024. Instituto Socioambiental | Povos Indígenas no Brasil. Available from https://pib.socioambiental.org/pt/Povo:Nukini [accessed 4 Feb. 2025].
Damián A., Mitidieri N. & Chiron G. 2018. A taxonomic synopsis of Acianthera (Orchidaceae: Pleurothallidinae) in Peru, including two new species. Anales del Jardín Botánico de Madrid 75: e069. https://doi.org/10.3989/ajbm.2449
Flora e Funga do Brasil. 2025. Jardim Botânico do Rio de Janeiro. Available from http://floradobrasil.jbrj.gov.br/ [accessed 26 Nov. 2025].
Haag N.A. & Henriques M.H. 2014. Património Geológico do Parque Nacional da Serra do Divisor (Acre, Brasil): uma avaliação qualitativa. Comunicações Geológicas 101, Especial III: 1279–1282.
IBGE. 1994. Projeto de proteção do meio ambiente e das comunidades indígenas: diagnóstico geoambiental e socioeconômico - Área de influência da BR-364 trecho RioBranco/Cruzeiro do Sul. Rio de Janeiro, IBGE/IPEA.
IUCN. 2024. Guidelines for Using the IUCN Red List Categories and Criteria, Version 16. Prepared by the Standards and Petitions Committee. Available from https://www.iucnredlist.org/documents/RedListGuidelines.pdf [accessed 26 Nov. 2025].
Jørgensen P.M. & León-Yánez S. 1999. Catalogue of the vascular plants of Ecuador. Monographs in Systematic Botany from Missouri Botanical Garden 75: 1–1182.
Karremans A.P. & Vieira-Uribe S.V. 2020. Pleurothallids Neotropical Jewels. Volume 1. Imprensa Mariscal, Quito.
Karremans A.P., Bogarín D., Díaz-Morales M., Fernández M., Oses L. & Pupulin F. 2016. Phylogenetic reassessment of Acianthera (Orchidaceae: Pleurothallidinae). Harvard Papers in Botany 21: 171–187. https://doi.org/10.3100/hpib.v21iss2.2016.n4
Karremans A.P., Moreno J.S., Gil-Amaya K., Morales N.G., Espinosa F., Mesa S., Restrepo E., Rincón-González M., Serna A., Sierra-Ariza M. & Vieira-Uribe S. 2023. Colombian Orchidaceae: a catalogue of the Pleurothallidinae. Lankesteriana 23: 181–400. https://doi.org/10.15517/lank.v23i2.56158
Koga D.M., Brown I.F., Fearnside P.M., Salisbury D.S. & Silva S.S. 2022. Serra do Divisor National Park: A protected area under threat in the southwestern Brazilian Amazon. Environmental Conservation 49: 74–82. https://doi.org/10.1017/S0376892922000091
Kolanowska M. & Szlachetko D.L. 2020. Acianthera lueri, a new orchid species from the Peruvian Amazon region. Systematic Botany 45: 6–10. https://doi.org/10.1600/036364420X15801369352252
Luer C.A. 2004. Icones Pleurothallidinarum XXVI. Systematics of Pleurothallis subgenus Acianthera (Orchidaceae). Monographs in Systematic Botany from the Missouri Botanical Garden 95: 1–114. https://doi.org/10.5962/bhl.title.149317
Luer C.A. 2009. Miscellaneous new species in the Pleurothallidinae (Orchidaceae). Selbyana 30: 1–71. https://doi.org/10.5962/bhl.part.4453
Luer C.A. 2011. Miscellaneous new species in the Pleurothallidinae (Orchidaceae) excluding species from Brazil. Harvard Papers in Botany 16: 311–360. https://doi.org/10.3100/0.25.016.0206
Luer C.A. & Thoerle L. 2012. Miscellaneous new species in the Pleurothallidinae (Orchidaceae). Harvard Papers in Botany 17: 333–368. https://doi.org/10.3100/025.017.0214
Luer C.A. & Thoerle L. 2013. Miscellaneous new species in the Pleurothallidinae (Orchidaceae). Harvard Papers in Botany 18: 173–196. https://doi.org/10.3100/025.018.0212
Luer C.A. & Toscano de Brito A.L.V. 2002. Miscellaneous new species of the Pleurothallidinae from Brazil. Selbyana 23(2): 181–195.
Marcusso G.M., Azevedo I., Biral L., Demarchi L.O., Forzza R.C., Goldenberg R., Marinho L.C., Michelangeli F.A., Teles A.M. & Zartman C.E. 2025. Botanical novelties from the Serra do Divisor National Park in the extreme western Brazilian Amazon. Acta Amazonica 55: e55bc25076. http://doi.org/10.1590/1809-4392202500761
Mendonça B.A.F., Schaefer C.E.G.R., Fernandes-Filho E.I., Simas F.N.B. & Amaral E.F. 2020. Genesis and micropedology of soils at Serra do Divisor and Moa River floodplain, northwestern Acre, Brazilian Amazonia. Revista Brasileira de Ciência do Solo 44: e0200038. https://doi.org/10.36783/18069657rbcs20200038
Ministério das Minas e Energia. 1977. Projeto RADAMBRASIL: Levantamento de Recursos Naturais. Vol. 15. Folha SB.19 Juruá. Geologia, geomorfologia, pedologia, vegetação e uso potencial de terra. Departamento Nacional da Produção Mineral, Rio de Janeiro.
Obermüller F.A., Medeiros H., Colli-Silva M., Silveira M., Almeida T., Delprete P.G., Moraes P.R.L., Alves-Araújo A.G., Azevedo I.H.F., Fiaschi P., Cardoso D., Filardi F.R., Lima H.C., Carrijo T.T., Lohmann L.G., Mello-Silva R., Goldenberg R., Daly D. & Forzza R.C. 2020 Lista de espécies de plantas vasculares do Parque Nacional da Serra do Divisor. In: Catálogo de Plantas das Unidades de Conservação do Brasil. Jardim Botânico do Rio de Janeiro. Available from https://catalogo-ucs-brasil.jbrj.gov.br [accessed 29 Jan. 2026].
Oppenheim V. 1936. Notas ethnographicas sobre os indígenas do alto Juruá (Acre) e Valle do Ucayaly (Perú). Anais da Academia Brasileira de Ciências 8: 145–155.
Pérez-Escobar O.A., Oses L.M., Solano R., Rodríguez L.K., Zuluaga A. & Bogarín D. 2022. Acianthera hagsateri (Pleurothallidinae), a new species from the sub-andean forest of Colombia. Lankesteriana 22: 17–24. https://doi.org/10.15517/lank.v22i1.50813
Pérez-Escobar O.A., Bogarín D., Przelomska N.A.S., Ackerman J.D., Balbuena J.A., Bellot S., Bühlmann R.P., Cabrera B., Cano J.A., Charitonidou M., Chomicki G., Clements M.A., Cribb P., Fernández M., Flanagan N.S., Gravendeel B., Hágsater E., Halley J.M., Hu A.-Q., ... & Antonelli A. 2024. The origin and speciation of orchids. New Phytologist 242: 700–716. https://doi.org/10.1111/nph.19580
Pridgeon A.M., Cribb P.J., Chase M.W. & Rasmussen F.N. 2005. Genera Orchidacearum, 4. Epidendroideae (Part One). Oxford University Press, Oxford. https://doi.org/10.1093/oso/9780198507123.001.0001
Rodrigues V.T., Smidt E.C. & Barros F. 2015. Revisão taxonômica de Acianthera sect. Pleurobotryae (Orchidaceae, Pleurothallidinae). Hoehnea 42 (4): 615–627. https://doi.org/10.1590/2236-8906-60/2015
Rojas-Alvarado G. & Karremans A. 2024. A typological and morphological analysis of the Pleurothallidinae (Orchidaceae) inflorescences. The Botanical Review 90: 221–250. https://doi.org/10.1007/s12229-024-09303-6
Solano Gomez R. 2015. A taxonomic synopsis of the Mexican species of Acianthera (Orchidaceae: Pleurothallidinae) including a new species. Phytotaxa 218 (1): 039–060. https://doi.org/10.11646/phytotaxa.218.1.3
Solano R. & Karremans A.P. 2023. A review of Acianthera subgenus Brenesia (Orchidaceae, Pleurothallidinae), with a new species from Mexico. Acta Botanica Mexicana 130: e2225. https://doi.org/10.21829/abm130.2023.2225
Thiers B. continuously updated. Index Herbariorum: A global directory of public herbaria and associated staff. New York Botanical Gardens Virtual Herbarium. http://sweet gum.nybg.org/science/ih/
Turland N.J., Wiersema J.H., Barrie F.R., Gandhi K.N., Gravendyck J., Greuter W., Hawksworth D.L., Herendeen P.S., Klopper R.R., Knapp S., Kusber W.-H., Li D.-Z., May T.W., Monro A.M., Prado J., Price M.J., Smith G.F. & Zamora Señoret J.C. 2025. International Code of Nomenclature for Algae, Fungi, and Plants (Madrid Code). Regnum Vegetabile 162. University of Chicago Press, Chicago. https://doi.org/10.7208/chicago/9780226839479.001.0001
Copyright (c) 2026 Gabriel Mendes Marcusso, Leonardo Biral, Layon Oreste Demarchi, Charles E. Zartman
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