Vol.:(0123456789) KEW BULLETIN DOI 10.1007/S12225-023-10092-1 © The Board of Trustees of the Royal Botanic Gardens, Kew, 2023 Vanilla calamitosa (Orchidaceae), a new aphyllous species from eastern Brazil Denis N. Carvalho 1 , Thiago E. C. Meneguzzo 2,3,4 & Cássio van den Berg 1 Summary. Vanilla calamitosa is described and illustrated from southern Bahia. Its conservation status is assessed as Critically Endangered (CR). Vanilla calamitosa is the second known aphyllous species in South America and the sixth of the Americas. The other aphyllous species in the continent is V. penicillata, which has occasionally been misidentified as V. eggersii. Resumo. Vanilla calamitosa é descrita, ilustrada como uma espécie nova do sul da Bahia. Ela é a segunda espécie áfila da América do Sul e a sexta das Américas. O estado de conservação é inferido como “Criticamente em Perigo” (CR). A outra espécie áfila do continente é V. penicillata, a qual ocasionalmente é incorretamente identificada como V. eggersii. Key Words. biodiversity, Neotropics, taxonomy, Vanilloideae. Introduction Vanilla Plum. ex Mill. in Miller (1974: s.n.) is one of the few pantropical genera of Orchidaceae and includes about one hundred species (Chase et al. 2015; PoWO 2023). Some species have their aromatic fruits commer- cially exploited for the production of the spice homo- nym for the genus (Cameron 2011). Many species are widely distributed, relatively well known and illustrated, while others are poorly sampled with badly conserved specimens and even only known by their nomenclatu- ral types (Soto Arenas & Dressler 2010; Karremans et al. 2020). Most of the herbarium specimens bear fruits, whilst a reduced number of herbarium specimens bear open flowers due to their ephemerality (Soto Arenas & Dressler 2010). All these matters have made the study of the genus slower when compared to other orchid genera. The state of the art of Brazilian species of Vanilla is no different from that of those from the rest of the globe. A very peculiar group of Vanilla species consists of aphyllous species that have lost or lack fully developed leaves with a blade (Cameron 2018). Five of the six New World aphyllous species are distributed in the Carib- bean and sparsely in surrounding continental areas, occurring in hot and dry habitats: V. barbellata Rchb.f. (Reichenbach 1865: 274), V. claviculata Sw. (Swartz 1799: 66), V. dilloniana Correll (1946: 331), V. marmoreisensis Soto Calvo, Esperon & Sauleda (2019: 56), and V. poitaei Rchb.f. (Reichenbach 1876: 66) (Soto Arenas & Cribb 2010; Cameron 2011; Soto Calvo et al. 2019; data sum- marised in Table 1). The only previously known South American aphyllous species has been reported from Venezuela and Brazil, in moist forests, and is named V. penicillata Garay & Dunst. in Dunsterville & Garay (1965: 324). The Old World aphyllous species are V. aphylla Blume (1825: 422) from Myanmar, Laos, Thailand, Vietnam, Malaysia, and Indonesia; V. madagascariensis Rolfe (1896: 476) and V. phalaenopsis Rchb.f. ex Van Houtte in Van Houtte (1868: 17) endemic to Mada- gascar; V. roscheri Rchb.f. (Reichenbach 1876: 65) from Ethiopia, Kenya, Somalia, Tanzania (including Zanzibar and Pemba), Mozambique, South Africa; and V. wightii Lindl. ex Wight in Wight (1845: sub t. 931) from India (Soto Arenas & Cribb 2010). Rolfe published Vanilla sect. Aphyllae Rolfe (1896: 471) for all leafless species, but including all leafless species as a single group is untenable for phyloge- netic reasons. Cameron (2018) pointed out that the loss of leaves evolved at least three times in the genus. Even though the leaflessness is not a monophyletic char- acteristic, it is very useful for matters of comparative morphology on the grounds of alpha taxonomy, and therefore it is used in the context of the present study. ISSN 1874-933X (print) ISSN 0075-5974 (electronic) Accepted for publication 7 March 2023. 1 Universidade Estadual de Feira de Santana, Programa de Pós-graduação em Botânica, Av. Transnordestina, s.n, Feira de Santana, Bahia 44036-900, Brazil. e-mail: denisnunis-@hotmail.com 2 Instituto de Pesquisas Jardim Botânico do Rio de Janeiro, Rua Pacheco Leão 915, Rio de Janeiro 22460-030, Brazil 3 Universidade de Brasília, Instituto de Ciências Biológicas, Departamento de Botânica, caixa postal 4457, Brasília, Distrito Federal 70919-970, Brazil 4 Museu Nacional, Departamento de Botânica, Quinta da Boa Vista s.n., São Cristóvão, 20940-040 Rio de Janeiro, Brazil