BRAZIL • Matto Grosso, near Palmeiras; 15°58’14”S, 55°32’10”W; 24 Dec. 1893; C.A.M. Lindman 2481; holotype: S [S08-5056]; isotypes: S [S08-5055, S-R-6327].

Epiphytic herbs, long scandent. Roots axillary, one per node; aerial roots 1.5–2.5 mm diam., velamenous, glabrous, simple, whitish to greenish; storage roots up to 5 mm diam., branching, white. Stem climbing, sinuous, cylindrical, fleshy, glabrous, green to yellowish green; internodes 40–90 × 5–9 mm. Leaves 7–16 × 3.5–6 cm, alternate, distichous, elliptic to lanceolate, rarely ovate, symmetric or asymmetric, fleshy, glabrous, green to yellowish green, margin entire, apex acute to acuminate, pseudopetiolate; pseudopetiole concave, 4–8 mm long. Inflorescence 2–3 cm long, apical, racemose, pending, with up to 13 flowers opening in succession; 1 flower opening each morning; bracts 5–16 × 3–11 mm, progressively smaller toward the apex, alternate, triangular to ovate, coriaceous, concave, patent, apex acute, sometimes leafy. Flowers resupinate, pedicellate, with an abscission layer between perianth and ovary; pedicel with ovary 2.4–2.8 × 0.3–0.34 cm, straight to incurved, calyculate, cylindrical in transverse section, white along the pedicel and green along the ovary; calycule green, persistent. Sepals 6.3–6.8 × 0.9–1.1 cm, free, oblanceolate, fleshy, slightly concave, internally pale yellow, externally yellow, apex obtuse, margin entire, slightly reflexed; dorsal sepal symmetric; lateral sepals asymmetric. Petals 6–6.2 × 1.8–2 cm, free, obelliptic to spatulate, asymmetric, membranous, apex acute, slightly reflexed, yellow, adaxial surface with a central and longitudinally arranged keel. Labellum 3-lobed, 6.1–6.4 × 3.5–3.8 cm, unguiculate, tubular, yellow, whitish in the basal portion, inner surface with longitudinal prominent stripes converging in four triangular protuberances and in a cluster of the digitiform secretory trichomes at the entrance of the nectar chamber; central crest (nectar guide) ca 5 mm wide, with longitudinal yellow strips near the apex, and with a channel-like depression ca 2 mm wide (concave) just below the anther and stigma; labellum margins fused from the base to ca ¾ of the column length forming a tubular nectar chamber; nectar chamber 2.2–2.4 cm long; lateral lobes obliquely rounded, margins undulate; apical lobe emarginated, reflexed, margin undulate. Column 4.1–4.3 × 0.35–0.38 cm, semi-cylindrical, slender, base attenuate, dilated towards the apex, with white-hyaline hairs close to the stigma, apex with two projections (wings) facing downwards; anther 4–4.2 × 3.7–4 mm, rhomboid, yellowish, versatile; rostellum 4–4.2 × 3.5–3.8 mm, trapezoidal, white. Fruits 5.4–6.7 × 1.1–2 cm, linear to clavate, strait to incurved, cylindrical to subcylindrical in transverse section, fleshy, dehiscent, opening in two valves, green when immature, yellowish when mature. Seeds ca 0.5 mm, ovate, crustose, black.

Figure 1. 

Vanilla lindmaniana Kraenzl. A. Detail of a flowering plant. B. Flower in diagonal view. C. Flower in lateral view. D. Flower in front view. E. Dissected perianth. Note the nectar chamber (arrow). F. Detail of the adaxial surface of a petal showing the longitudinal keel. G. Detail of the labellum in upper view. H. Detail of the apex of the labellum of a flower showing the longitudinal cavity. I. Detail of the labellum showing the central labellar crest. J. Pedicel, ovary, labellum, and column in lateral view. K. Pedicel, ovary, labellum, and column in dorsal view. L. Pedicel, ovary, and column in lateral view. M. Pedicel, ovary, and column in ventral view. N. Apex of the column: in lateral view with an articulated anther (above), and in ventral view with an articulated and disarticulated anther (below). Note the lateral wings (arrowheads). O. Mature fruit in lateral view. P. Transversal section of a mature fruit. Based on VAN 034 (LBMBP).

Vanilla lindmaniana occurs in open forests of the Amazonia, Cerrado, and Pantanal Biomes (Fig. 3). Vanilla lindmaniana has an epiphytic habit, rooting on the trunk and leaves of palm trees of the genera Acrocomia Mart., Attalea Kunth., and Mauritia L.f. (Barberena et al. 2019; Table 1). The elevation is from 100 to 500 m a.s.l. Flowers open in the morning hours and each flower lasts ca 12 hours. In a study involving populations from Maranhão State (Brazil), it was found that the flowers of V. lindmaniana (as V. palmarum) offer nectar as a reward which is stored in the nectar chamber. Vanilla lindmaniana has a mechanism of facultative self-pollination. Its flowers are chasmogamous and pollinated by hummingbirds but in the absence of biotic pollination, flowers self-pollinate (Pansarin and Ferreira 2022).

Vanilla lindmaniana blooms from December to January. The fruits ripen between July and August.

Endangered: EN B2a(ii,iii). Vanilla lindmaniana is a rarely collected species currently known to grow in the Amazonian Rainforest and Cerrado of South America. The extent of occurrence (EOO) is estimated to be 5,310,777 km², which falls within the limits for Least Concern (LC), according to the IUCN Red List categories and criteria and guidelines. The area of occupancy (AOO) is estimated to be 108 km² (cell width of 2 km), which falls within the limits for Endangered (EN) under criterion B2 (area of occupancy). Considering that the Amazon Rainforest and especially the Brazilian Cerrado have been reduced to scattered fragments due to extensive human occupation, I project a continuing decline in (ii) area of occupancy and (iii) extent and/or quality of the habitat of V. lindmaniana. Based on these threats, V. lindmaniana is assessed as Endangered.

BOLIVIA – Beni • Tumi Chucua, 30 km S of Riberalta, flood plain forest, Vaca Diez; 11°07’59”S, 66°09’59”W; 210 m; 29 Sep. 1981; J.C. Solomon 6503; MO. – Pando • Frederico Román, on the west bank of the Madeira River, ca 1 km south of Cachuela Las Pedritas; 09°57’13”S, 65°20’13”W; 20 Jul. 2002; J. Urrelo et al. 501; V. – Santa Cruz • San Jose de Campamento, a 3 km sobre el caminho hacia San Roque, José Miguel de Velasco; 15°09’20”S, 60°59’29”W; 9 May 1996; R. Guillén 4343; NY • Velasco, Parque Nacional Noel Kempff Mercado, 500 m al S de la comunidade Florida hacia el Campamento Toledo; 14°33’00”S, 60°49’00”W; 2 Dec. 1994; R. Guillén & R.A. Medina Guillén Villarroel 2701; MO • Velasco, Reserva Ecológica El Refúgio, a 300 m al SO de campamento, em la pampa de las islas; 14°47’09”S, 61°03’14”W; 150 m; 21 Jan. 1995; R. Guillén & R.A. Medina Guillén Villarroel 2944; MO.

BRAZIL – Amazonas • Manaus, Ramal Vale do Novo Amanhecer, ao lado do sítio Toc; 02°27’00”S, 60°06’00”W; 12 Oct. 2014; A.H. Krahl 471; INPA • Manaus, Reserva Florestal Ducke, Manaus-Itacoatiara, km 26; 02°52’59”S, 59°58’00”W; 29 Jun. 1994; J.E.L.S. Ribeiro 1333; NY. – Goiás • Colinas do Sul, Estrada de acesso ao rio Preto, km 1, a partir da entrada da fazenda Vale das Araras, Mata de galeria perturbada, com alta presença de babaçu, Relevo suave ondulado, Solo areno-argiloso, Área de influência da futura Hidrelétrica de Cana Brava; 13°44’22”S, 48°07’42”W; 310 m; G. Pereira-Silva et al. 5573; BHCB • Uruaçu, Reservatório em formação do AHE Serra da Mesa, Originalmente mata ciliar alterada; 14°31’28”S, 49°08’26”W; 15 Oct. 2007; S.P. Cordovil-Silva & J.B. Pereira 705; BHCB. – Maranhão • Estreito, Canteiro de obras do UHE Estreito (próximo ao porto da balsa); 06°33’38”S, 47°27’03”W; 150 m; 11 Mar. 2007; G. Pereira-Silva 11374; CEN • Passagem Franca, a 24 km de Buriti Bravo, à esquerda no Café Buriti mais 22 km do posto fiscal, à direita mais 60 km; 06°20’59”S, 43°31’59”W; 270 m; 24 Nov. 1993; R.F. Vieira et al. 1545; BHCB • São Luís, Araçagy, Base do Cabral; 02°28’30”S, 44°12’53”W; 11 Apr. 1988; R. Nina 98; SLUI • São Luís, UFMA, campus Dom Delgado, em frente ao centro pedagógico Paulo Freire; 02°33’43”S, 44°18’37”W; 20 Aug. 2019; K.N. Santos 122; SLUI. – Mato Grosso • Cáceres; 16°04’14”S, 57°40’44”W; Aug. 2003; M.A. Carniello 55; HRCB • Cocalinho; 14°23’49”S, 50°59’44”W; 1 Jan. 1997; A.F. Rozza et al. 490; ESA • Barra dos Bugres; 15°04’22”S, 57°10’51”W; 20 Jun. 2012; s.col.; HCF [HCF10838]. – Mato Grosso do Sul • Aquidauana; 20°28’15”S, 55°47’13”W; 8 Dec. 2001; M.A. Assis 1521; HRCB • Corumbá, Passo do Lontra; 19°34’35”S, 57°01’05”W; 106 m; 30 Jul. 2007; M.G. Caxambú 1598; HCF • Corumbá, Morro na margem da Baía Mandiré; 19°00’33”S, 57°39’11”W; 18 Oct. 2002; G.A. Damasceno Júnior et al. 2533; HUFU • Balneário Iracema, Região de A. Maria Coelho; 19°00’33”S, 57°39’11”W; 21 Nov. 2004; D.P. Rodriguez & H. Baracat s.n.; UPCB [UPCB104531] • Ladário, Fazenda Vale do Paraíso; 19°00’16”S, 57°36’06”W; 110 m; 28 Oct. 2004; E.R. Macedo et al. 5; MBM. – Pará • Breves; 01°40’55”S, 50°28’49”W; 17 Jul. 1950; G.A. Black & R.L. Fróes 10036; IAN • Melgaço, Floresta Nacional de Caxiuanã, rio Curuá-grande, margem esquerda; 01°48’15”S, 50°42’43”W; 29 Nov. 2010; A.K. Koch & C. Souza 347; IAN. – Rondônia • Guajará-Mirim, 23 km de centro de Guajará-Mirim, Colônia do Yata; 10°46’58”S, 65°20’21”W; 15 Oct. 1990; L.B. Bianchetti 1092; HUEFS • Porto Velho, nas margens da BR-364; 08°45’42”S, 63°54’14”W; 100 m; 19 Aug. 2022; M. Figueira 1876; CEN. – Tocantins • Paranã, Canteiro de obras do UHE São Salvador (área do bota-fora); 12°36’55”S, 47°52’59”W; 260 m; 19 Jun. 2006; G. Pereira-Silva 10786; CEN • Paranã; 12°52’34”S, 48°10’41”W; E.R. Santos et al. 1094; HUTO.

GUYANA – Essequibo • South Rupununi Savanna, Kidekperdana Creek, 8 km SE of Aishalton, Upper Takutu-Upper Essequibo; 02°25’11”N, 59°10’12”W; 26 Nov. 1993; T.W. Henkel 3510; NY.

PERU – Madre de Dios • Cusco Amazónico Lodge, Río Madre de Dios, Lago Sandobal, 10 km NE of Puerto Maldonado, Tambopata; 12°34’59”S, 69°02’59”W; 200 m; Jun. 1990; P. Núñez & V. Núñez Vargas 12287; MO.

VENEZUELA – Bolivar • Bolivar; 12 Jan. 1961; J.A. Steyermark 88386; UB.

Vanilla lindmaniana was described based on a specimen collected by Carl A.M. Lindman (Lindman 2481 (S)) in the municipality of Palmeiras, in the current state of Mato Grosso do Sul. The region is located in the Pantanal Biome. For a long time, this species has been considered as an obscure taxon endemic to Brazil (BFG 2018). However, several characteristics such as the epiphytic habit, the colour of the flowers, and the absence of a penicillate callus have been used to consider this taxon as conspecific with V. palmarum (e.g. Soto Arenas and Cribb 2010). Here, V. lindmaniana is presented as a taxon clearly distinct from V. palmarum, being recognized by several vegetative and floral characteristics. According to the infrageneric classification of Soto Arenas and Cribb (2010), V. lindmaniana is a member of the V. palmarum group.

Vanilla lindmaniana is easily recognized from other Neotropical species by its epiphytic habit on palms, by its terminal and pendant inflorescences, by its yellow flowers much smaller than those of V. pompona, by the absence of a penicillate callus on the labellum, and by its dehiscent and scentless fruits. The species is closely related to V. palmarum, however, V. lindmaniana is clearly distinguishable by its distribution across the Pantanal, Cerrado, and Amazonia Biomes, by its larger flowers and leaves, the presence of a nectar guide with a channel-like depression just below the anther and stigma, and the larger fruits, which are rounded in transversal section (Table 1).

BRAZIL • Bahia, s.loc.; s.d.; P. Salzmann s.n.; isotypes: K [K000293255], MPU [MPU013457, MPU018359, MPU018360], G [G00190804, G00190913].

Epiphytic herbs, long scandent. Roots axillary, one per node; aerial roots 1–1.5 mm diam., velamenous, glabrous, simple, whitish to creamy; storage roots up to 4 mm diam., branching, white. Stem climbing, sinuous, cylindrical, fleshy, glabrous, glaucous to green with whitish dots; internodes 25–50 × 2.5–5 mm. Leaves 3.5–8.5 × 2–4 cm, alternate, distichous, elliptic to ovate, symmetric or asymmetric, fleshy, glabrous, glaucous to yellowish green, margin entire, apex acute to acuminate, pseudopetiolate; pseudopetiole concave, 3–5 mm long. Inflorescence 1.8–2.5 cm long, apical, racemose, pending, with up to 10 flowers opening in succession; 1 flower opening each morning; bracts 5–15 × 3–8 mm, progressively smaller toward the apex, alternate, triangular to elliptic, coriaceous, concave, patent, apex acute, sometimes leafy. Flowers resupinate, pedicellate, with an abscission layer between perianth and ovary; pedicel with ovary 2.3–2.6 × 0.4–0.6 cm, straight to incurved, calyculate, subcylindrical in transverse section, white along the pedicel and green along the ovary. Sepals 4.7–5.1 × 0.9–1.1 cm, free, oblanceolate, fleshy, slightly concave, internally pale yellow, externally yellow, apex obtuse, margin entire, reflexed at apex; dorsal sepal symmetric; lateral sepals asymmetric. Petals 4.8–5.1 × 1.2–1.4 cm, free, spatulate, asymmetric, membranous, apex acute, slightly reflexed, yellow, adaxial surface with a central and longitudinally arranged keel. Labellum 1-lobed to slightly 3-lobed, 5.1–5.3 × 3.9–4.1 cm, unguiculate, tubular, yellow, whitish in the basal portion, inner surface with longitudinal prominent stripes converging in two triangular protuberances and in a cluster of the digitiform secretory trichomes at the entrance of the nectar chamber; central crest (nectar guide) ca 5 mm wide near the apex, and with an elevation ca 4 mm wide (convex) just below the anther and stigma; labellum margins fused from the base to ca ¾ of the column length forming a tubular nectar chamber; nectar chamber 1.3–1.6 cm long; lateral lobes obliquely rounded, margins undulate; apical lobe emarginated, reflexed, margin undulate. Column 3.4–3.6 × 0.34–0.37 cm, semi-cylindrical, slender, base attenuate, dilated towards the apex, with white-hyaline hairs close to the stigma, apex with two lateral projections (wings) facing upward; anther 3.6–3.9 × 3.5–3.8 mm, rhomboid, yellowish, versatile; rostellum 3.8–4 × 3.5–3.8 mm, trapezoidal, white. Fruits 4.4–6.5 × 0.8–1.4 cm, linear, incurved, diamond-shaped in transverse section, fleshy, dehiscent, opening in two valves, green when immature, yellowish when mature. Seeds ca 0.5 mm, crustose, ovate, black.

Figure 2. 

Vanilla palmarum (Salzm. ex Lindl.) Lindl. A. Detail of a flowering plant. B. Flower in diagonal view. C. Flower in lateral view. D. Flower in front view. E. Dissected perianth. Note the nectar chamber (arrow). F. Detail of the adaxial surface of a petal showing the longitudinal keel. G. Labellum in upper view. H. Detail of the apex of the labellum of a flower showing the longitudinal keel. I. Detail of the labellum showing the central labellar crest. J. Pedicel, ovary, labellum, and column in lateral view. K. Pedicel, ovary, labellum, and column in dorsal view. L. Pedicel, ovary, and column in lateral view. M. Apex of the column: in lateral view with an articulated anther (above), in lateral view with the anther removed (mid), and in ventral view with an articulated anther (below). Note the lateral wings (arrowheads). N. Anther in ventral view (above) and dorsal view (below). O. Mature fruit in lateral view. P. Transversal section of a mature fruit. Based on VAN 113 (LBMBP).

Vanilla palmarum is a Brazilian endemic species widely distributed in the Caatinga and Atlantic Forest Biomes, occurring in open forests of north-eastern Brazil (Fig. 3). Vanilla palmarum has an epiphytic habit, rooting on the trunk of several palm species of the genera Elaeis Jacq. and Syagrus Mart. (Barberena et al. 2019; Table 1). The elevation is from 212 to 1123 m a.s.l. Flowers open in morning hours and each flower lasts ca 12 hours. As in V. lindmaniana (Pansarin and Ferreira 2022), the flowers of V. palmarum offer nectar as a reward which is stored in the nectar chamber. Flowers of V. palmarum also shows a mechanism of facultative self-pollination. Its flowers are chasmogamous but in the absence of biotic pollination, flowers self-pollinate (Emerson Pansarin unpubl. data). Although V. lindmaniana is pollinated by hummingbirds (Pansarin and Ferreira 2022), the flowers of V. palmarum do not appear to be adapted for avian pollination as their central crest (nectar guide) is convex. In V. lindmaniana, the labellum shows a channel-like depression of ca 2 mm wide, whose function is to guide the hummingbird’s bill to the entrance of the nectar chamber (Pansarin and Ferreira 2022).

Figure 3. 

Occurrence map of Vanilla lindmaniana Kraenzl. and Vanilla palmarum (Salzm. ex Lindl.) Lindl.

Vanilla palmarum blooms from December to February. The fruits ripen between July and September.

Endangered: EN B2a(ii,iii). Vanilla palmarum is a rarely collected species currently known from the Atlantic Forest and Caatinga Biomes of Brazil. The extent of occurrence (EOO) is estimated to be 657,099 km², which falls within the limits for Least Concern (LC), according to the IUCN Red List categories and criteria and guidelines. The area of occupancy (AOO) is estimated to be 108 km² (cell width of 2 km), which falls within the limits for Endangered (EN) under criterion B2 (area of occupancy). Considering that both the Atlantic Forest and Caatinga Biomes have been reduced to scattered fragments due to extensive human occupation, we project a continuing decline in (ii) area of occupancy and (iii) extent and/or quality of the habitat of V. palmarum. Based on these threats, V. palmarum is assessed as Endangered (EN).

BRAZIL – Alagoas • Maceió, Serra da Saudinha, Fazenda Cela; 10°05’37”S, 36°11’28”W; 13 Jan. 2008; Chagas-Mota 243; MAC. – Bahia • Amargosa, Recôncavo Sul, entrada da porteira da Fazenda Acaju; 11°01’00”S, 39°36’00”W; 27 May 2005; M.A. Costa & M.L. Guedes 14; ALCB • Boa Nova, Parque Nacional de Boa Nova, setor central, Fazenda Alvorada, Lajedo dos Beija-flores; 14°21’45”S, 40°12’27”W; 1215 m; 2 Mar. 2013; L.Y.S Aona 2149; HUEFS • Caetité, Coleta arredores da área de preservação da Indústria Nucleares do Brasil - INB, Áreas 1 - Margem direita da Reserva Próximo a Lagoa, 2 - Barragem Wilson Gouveia, 3 - “Mulungu”; 14°04’09”S, 42°28’29”W; 26 Sep. 2009; J.L. Paixão 1552; HUEFS • Cravolândia, Sudoeste, Assentamento Palestina; 13°23’25”S, 39°49’13”W; 14 Aug. 2001; L. de J. Alves et al. 354; ALCB • Feira de Santana, Campus da Universidade Estadual de Feira de Santana; 12°12’01”S, 38°58’18”W; 5 Apr. 2018; M.F. Alves & J.L. Mayer 5; UEC • Campus da UEFS, Atrás do Centro Administrativo; 12°12’05”S, 38°58’05”W; 6 Oct. 1997; I.F. Castro et al. 31167; UB • Itatim, Morro do Agenor; 12°42’42”S, 39°41’53”W; 26 Nov. 1995; F. França 1465; HUEFS • Itatim, Fazenda na base do morro das Tocas; 12°42’42”S, 39°41’53”W; 282 m; 31 Aug. 2003; T.B. Cavalcanti 3190; CEN • Jacobina, Paraíso, Fazenda Exú; 11°10’50”S, 40°31’05”W; 11 Aug. 2006; s.col. 11223; EAN [EAN21562] • Saubara; 12°44’15”S, 38°46’07”W; 15 Aug. 2017; K. Martins & A. Figueiredo 13; HST • Jacobina, Piemonte da Diamantina, Arredores do Povoado de Tamanco; 11°10’50”S, 40°31’05”W; 28 Apr. 2012; T.L. Vieira et al. 91; ALCB • Lajedinho, Chapada Diamantina; 12°21’20”S, 40°54’20”W; 23 Aug. 2014; G.S. Silva et al. 633; HUESB • Milagres, Serra do Jatobá; 12°52’11”S, 39°51’32”W; 21 May 2021; L.Y.S. Aona 5955; HURB • Retirolândia, Fazenda Piabas, próximo ao riacho; 11°29’41”S, 39°25’32”W; 212 m; 1 Nov. 1999; R.P. Oliveira 308; HUEFS • Salvador, Região Metropolitana de Salvador, Ilha de Maré, Povoado de Bananeiras; 12°44’58”S, 38°31’42”W; 12 Jun. 2011; M.L. Guedes et al. 18375; ALCB • Sento Sé, Parque Nacional Boqueirão da Onça, Entrada para Alegre, Vindo do Povoado Almas; 09°44’45”S, 41°53’06”W; 1123 m; 4 Sep. 2013; D.S. Fernandes 86; HVASF • Valente, Mata nativa, localizada a 4 km do centro, sentido a saída para Retirolândia; 11°26’29”S, 39°27’18”W; 326 m; 10 Jun. 2017; M.R.L. Constantino 33; MBML • Umburanas, PNBO, Umburanas; 723 m; 22 Sep. 2006; J.A. Siqueira Filho 1799; HVASF • Wagner, Mata ciliar do rio Tijuco; 12°13’32”S, 41°15’24”W; 17 Nov. 2018; E.B. Lopes & M.L. Guedes 71; ALCB. – Ceará • Viçosa do Ceará; 03°33’43”S, 41°05’31”W; 29 Dec. 2005; A.S.F. Castro 1661; EAC. – Minas Gerais • Salto da Divisa, Fazenda Santana; 16°04’16”S, 40°03’19”W; 137 m; 20 Feb. 2003; J.A. Lombardi et al. 5105; BHCB. – Paraíba • Barra de Camaratuba, Estrada Rural; 06°36’37”S, 35°05’58”W; 42 m; 17 Jul. 2014; J.M.P. Cordeiro et al. 269; EAN. – Pernambuco • Arcoverde, Descobrimento, Assentamento Serrote Redondo, Corredor Ecológico Ramal do Agreste e Pacuera Ipojuca; 08°21’12”S, 36°57’38”W; 947 m; 5 Aug. 2019; A.P. Fontana & J.M. dos Santos 10946; HRSN • Buíque, Catimbau, trilha das torres; 08°37’00”S, 37°10’00”W; 17 Oct. 1994; E. Menezes 16; K [K000293254]. – Sergipe • Lagarto, Povoado Brejo; 10°55’02”S, 37°38’59”W; 24 Aug. 2009; L.A.S. Santos & F.B. Suzart 1; ASE.

Vanilla palmarum was described based on specimens collected in the state of Bahia, north-eastern Brazil. Vanilla palmarum has been assumed to be a widely distributed species, from Cuba to south-eastern Brazil. However, according to the data presented here, this taxon is endemic to Brazil, occurring in areas in the Caatinga and Atlantic Forest Biomes. The hypothesis of the occurrence of V. palmarum in Cuba requires careful further investigation. Two Vanilla names were described based on plant material collected in Cuba, namely V. savannarum Britton and V. lutea C.H. Wright ex Griseb. Although both taxa were synonymized under V. palmarum, they appear to be more closely related to V. lindmaniana. In addition, even though V. lindmaniana was published later than V. lutea, the latter is not a validly published name (e.g. BFG 2018). Vanilla savannarum was published later than V. lindmaniana, and therefore would be a synonym of this species. However, until fresh material is available for analysis, it seems to be prudent not to consider V. savannarum as a synonym of V. lindmaniana or V. palmarum. According to the infrageneric classification of Soto Arenas and Cribb (2010), V. palmarum is a member of the V. palmarum group.

Vanilla palmarum is easily recognized from other Neotropical species by its epiphytic habit on palm trees, by its terminal and pendant inflorescences, by its yellow flowers, by the absence of a penicillate callus on the labellum, and by its dehiscent and scentless fruits. Although closely related to V. lindmaniana, V. palmarum is easily distinguishable from it by its distribution in the Atlantic Forest and Caatinga Biomes, by its smaller vegetative and floral structures, the presence of a convex central crest (nectar guide) just below the anther and stigma, and the smaller fruits, which are diamond-shaped in transversal section (Table 1).