118 urn:lsid:arphahub.com:pub:71cc5dc6-a767-5334-951f-ef6ae8936459 Plant Ecology and Evolution plecevo 2032-3913 2032-3921 Meise Botanic Garden and Royal Botanical Society of Belgium 10.5091/plecevo.172513 172513 Research Article Angiospermae Bignoniaceae Core Eudicots: Asterids Lamiales Morphology & Anatomy Systematics Americas Brazil South America Taxonomic novelties in Adenocalymma (Bignonieae, Bignoniaceae) endemic to the Atlantic Forest Fonseca Luiz Henrique M. luizhmf@proton.me https://orcid.org/0000-0002-8140-3244 1 2 3 Conceptualization Writing - original draft Writing - review and editing Data curation Formal analysis Investigation Methodology Software Visualization da Silva Ribeiro Ricardo https://orcid.org/0000-0002-7312-1861 1 4 Writing - original draft Writing - review and editing Data curation Formal analysis Investigation Visualization Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil Universidade de São Paulo São Paulo Brazil Systematic and Evolutionary Laboratory, Department of Biology, Ghent University, Ghent, Belgium Ghent University Ghent Belgium Institut für Ökologie, Evolution und Diversität, Goethe-Universität Frankfurt, Frankfurt am Main, Germany Goethe-Universität Frankfurt Frankfurt am Main Germany Programa de Capacitação Institucional, Instituto Nacional da Mata Atlântica, Santa Teresa, Espírito Santo, Brasil Programa de Capacitação Institucional, Instituto Nacional da Mata Atlântica Santa Teresa Brazil

Corresponding author: Luiz Henrique M. Fonseca (luizhmf@proton.me)

Academic editor: Brecht Verstraete

 2026 08 01 2026 159 1 3 11 F0A947BF-5712-5A25-82E5-3DD1AF1B6671 0 18 09 2025 02 11 2025 Luiz Henrique M. Fonseca, Ricardo da Silva Ribeiro 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.

Background and aims – During ongoing morphological studies of Adenocalymma, we realized that nomenclatural updates are necessary in the genus. Here, we propose a new circumscription of A. acutissimum and the description of the new species A. darwinii.

Material and methods – Morphological and phylogenetic evidence support the new circumscription of A. acutissimum, while the new species is recognized based on morphological grounds and compared to A hirtum and A. salmoneum.

Key results – We removed the taxa A. comosum, A. comosum var. lanceolatum, and A. nitidum as synonyms of A. acutissimum. We also presented a detailed description for A. darwinii sp. nov., an illustration, and information on its distribution, habitat, phenology, and extinction risk. A map showing the occurrence of both A. comosum and A. darwinii sp. nov. is shown.

Conclusion – These results emphasize once again the importance of taxonomic studies in the Brazilian Atlantic Forest and highlight conservation concerns for its flora.

 Atlantic Forest Brazil liana new species Introduction

Adenocalymma Mart. ex Meisn. is a Neotropical genus of lianas, shrubs, and treelets with 76 species recently listed (Fonseca and Lohmann 2019a). It belongs to the tribe Bignonieae, the most speciose tribe of the Bignoniaceae with up to 400 species. The genus is centred in Amazonia and the Atlantic Forest. The remaining species occur in the South American dry diagonal, wet and dry forests of Central America, Colombia, Ecuador, and the Guiana Shield. Most of the species are found from low elevations to up to 2000 m (Lohmann and Taylor 2014; Fonseca and Lohmann 2019a).

The genus is circumscribed by morphological characters such as the presence of cupular glandular trichomes on the prophylls of the axillary buds, floral bracts, bracteoles, calyces, and fruits (Lohmann 2006; Lohmann and Taylor 2014; Fonseca and Lohmann 2019a). Phylogenomic hypotheses tackling the genus using plastome (Lohmann 2006; Fonseca and Lohmann 2018), mitochondrial, and nuclear genomes (Fonseca and Lohmann 2020) are available. These phylogenetic results led to a revised circumscription of the genus, which now includes the former Neojobertia Baill. and Pleonotoma albiflora (Salzm. ex DC.) A.H.Gentry (Fonseca and Lohmann 2019a; Gomes et al. 2020). Adenocalymma in its new circumscription received maximum support (Fonseca and Lohmann 2018; Fonseca and Lohmann 2020) and is corroborated by new phylogenetic results based on hundreds of nuclear genes (Fonseca and Lohmann in prep.).

The recent phylogenetic and nomenclature studies are part of an effort to better know this speciose but elusive genus of tropical plants. Previous morphological studies at the species level described four new species of Adenocalymma (i.e. Fonseca et al. 2016; Fonseca and Lohmann 2019b) and the transfer of a few others into the genus (Fonseca and Lohmann 2019a; Gomes et al. 2020). The new species were described from the Atlantic Forest and are distributed in semi-deciduous forests of south-eastern Brazil, in the states of Espírito Santo and Minas Gerais. They are rare elements in these forests with a few gatherings available for each species (Fonseca et al. 2016). Adenocalymma fistulosum L.H.Fonseca & L.G.Lohmann is an extreme example, with a single collection available (Fonseca and Lohmann 2019b).

As a result of the ongoing morphological and phylogenetic studies on Adenocalymma, we describe here a new species occurring in the semi-deciduous forest of Espírito Santo, Brazil. We also update the circumscription of Adenocalymma acutissimum Miers and reestablish Adenocalymma comosum DC. based on morphological and phylogenetic evidence (Fonseca and Lohmann 2018; Fonseca and Lohmann in prep.).

 Material and methods

Material was collected from field expeditions and herbaria, and a taxonomic treatment, distribution maps, and conservation analyses are presented, complemented by previously published phylogenetic evidence (see Fonseca and Lohmann 2018; Fig. 1). For the taxonomic treatment and description, analyses of material from the following herbaria were conducted: ESA, HRCB, HUEFS, HUESB, IBGE, K, MB, M, MO, NY, MBM, MBML, P, PEL, R, RB, RFA, RFFP, SP, SPF, UEC, VIC, and VIES (acronyms according to Thiers 2025). The type material of the new species was deposited in the MBML and SPF herbaria. Morphological descriptions and terminologies follow Radford et al. (1974), Lohmann and Taylor (2014), and Fonseca and Lohmann (2019a).

10.5091/plecevo.172513.figure1 729EE77B-C372-5FC0-8683-E4E796553E9A

Bayesian majority rule consensus tree derived from the analysis of the combined plastome and nuclear (pepC) datasets (adapted from Fonseca and Lohmann 2018). Bayesian posterior probabilities are shown above branches. Adenocalymma comosum and the new species A. darwinii are in bold.

https://binary.pensoft.net/fig/1505337

Distribution maps were constructed using data points provided by IBGE (2020) and the R packages terra v.1.8 (Hijmans 2025) and sf v.1.0 (Pebesma 2018; Pebesma and Bivand 2023) in R v.4.4 (R Core Team 2025). For the conservation status assessment, the categories and criteria of the IUCN Red List version 3.1 (IUCN 2012) were followed.

 Taxonomic treatment Plantae Lamiales Bignoniaceae B1407F66-C39B-5AC2-B53F-C18839181129 Adenocalymma comosum DC. (Candolle 1845: 209) Figs 1 , 2 , Table 1 Adenocalymma nitidum Mart. ex DC. (Candolle 1845: 200), syn. nov. – Type: BRAZIL – Rio de Janeiro • Magé, near Mandioca farm; Aug. 1817; von Martius CFP 39; lectotype (designated by Udulutsch et al. 2013: 633): M [M-0086336]; isolectotype: M [M-0086337]. Adenocalymma comosum var. nitidum (Mart. ex DC.) Bureau & K.Schum. (Schumann 1896: 89, as “nitida”) – Type: same as for Adenocalymma nitidum. Adenocalymma comosum var. lanceolatum Bureau & K.Schum. (Schumann 1896: 90, as “lanceolata”), syn. nov. – Type: BRAZIL – Rio de Janeiro • Rio de Janeiro: Tijuca Forest, Queimado hill; 17 Apr. 1870; A.M. Glaziou 4126; lectotype (designated by Udulutsch et al. 2013: 633): P [P00594790]; isolectotype: R [R000011389]. Bignonia comosa Cham. (Chamisso 1833: 693), nom. illeg. non B. comosa Roxb. (Roxburgh 1832: 103). Type

BRAZIL • s.loc.; s.d.; Sellow s.n.; lectotype (designated by Udulutsch et al. 2013: 632): K [K000449335]; isolectotype NY [NY00313142].

 Distribution and ecology

Adenocalymma comosum is known from the states of Minas Gerais, Rio de Janeiro, and São Paulo, Brazil (Fig. 2). This species is found in ombrophilous Atlantic Forest remnants, from coastal plains to the base of the “Serra do Mar.”

10.5091/plecevo.172513.figure2 D1A517EA-8A23-5307-B789-05C945FD6062

Distribution of Adenocalymma comosum (red) and A. darwinii (blue) in the Brazilian Atlantic Forest.

https://binary.pensoft.net/fig/1505338 Additional material examined

BRAZIL – Rio de Janeiro • Baía de Guanabara; 26 Aug. 1962; Pabst 7029; NY [NY00402976], MO, PEL [0001064] • Carapebus; 16 Jul. 1997; Silva 4058; R • Duque de Caxias; 30 Sep. 1931; Brade 11156; MO [MO081857], R • Duque de Caxias; 28 Jul. 1938; Passarelli 135; MO [MO031531] • Guapimirim; 6 Sep. 2013; Fonseca 207; SPF [SPF00213333] • Guapimirim; 6 Sep. 2013; Fonseca 208; SPF [SPF00213334] • Guapimirim; 6 Sep. 2013; Fonseca 209; SPF [SPF00213331] • Guapimirim; 14 Mar. 1992; Guedes 2275; RB [RB00559392], SPF [SPF00223019] • Guapimirim; 25 Mar. 1992; Vaz 961; MBM [MBM352581], RB [RB00559235] • Ilha Grande; 16 Aug. 2009; Maidi 988; RB • Itaipuassú; 14 Jan. 1982; Andreata 354; RB [RB00678536], RB [RB00054240] • Itatiaia; 23 Apr. 1941; Barros 267; RB [RB00473168, RB00479620, RB00533448] • Itatiaia; 26 Sep. 1940; Barros 3111; RB • Itatiaia; 7 May 1942; Barros 88; RB • Itatiaia; 27 Apr. 1995; Braga 2343; ESA, RB [RB00533210] • Magé; 25 Sep. 1985; Guedes 1313; RB [RB00054402] • Mangaratiba; 16 Jul. 2003; Bayão Jr. 12; HRCB • Mangaratiba; 16 Jul. 2003; Bayão Jr. 13; HRCB • Mangaratiba; 27 Dec. 2004; Bayão Jr. 132; HRCB • Mangaratiba; 13 Aug. 2003; Bayão Jr. 32; HRCB • Mangaratiba; 16 Jul. 2003; Menezes 1097; HRCB, RB [RB00006235] • Mangaratiba; 17 Jul. 2000; Menezes 34; HRCB • 31 Jul. 2001; Mangaratiba; Menezes 844; HRCB, RB [RB00007576] • Mangaratiba; 14 Jul. 1983; Pace 12; HRCB, RB [RB00002784] • Maricá; 23 Dec. 2001; Barros 1098; RB [RB00866361], RFFP [RFFP00015476] • Miguel Pereira; 1 Apr. 2015; Lima 7962; RB [RB00958082] • Niteroi; 6 Aug. 2003; Barros 2037; RB [RB00534838], RFFP [RFFP00017132] • Niteroi; 1 Aug. 1998; Barros 634; RB [RB00534812], RFFP [RFFP00015604] • Niterói; 7 Aug. 2001; Barros 1079; RB [RB00534865], RFFP [RFFP00016768] • Niterói; 14 Jul. 2006; Barros 2682; RB [RB00534883], RFFP [RFFP00017467] • Niterói; 26 Dec. 2005; Barros 2955; RB [RB00519021] • Nova Friburgo; 11 Jan. 1985; Gentry 49480; MO [MO031518], RB [RB00003094] • Nova Friburgo; 11 Jan. 1985, Gentry 49482; MO [MO031517] • Nova Iguaçu; 20 Jun. 1995; Silva Neto 627; RB • Paraty; 29 Jun. 1995; Campos 58; RB [RB00054330] • Paraty; 19 Oct. 1990; Frutuoso 106; RB • Paraty; 11 Apr. 1991; Giordano 1016; RB [RB00054092], VIC • Paraty; 3 Jul. 1992; Giordano 1338; RB [RB00054178] • Paraty; 29 Jun. 1993; Konno 177; RB [RB00686187] • Paraty; 3 Aug. 1989; Kurtz 73; RB [RB00054052], VIC • Paraty; 21 Nov. 1989; Marques 157; RB [RB00686230] • Paraty; 27 Sep. 1991; Marquete 404; IBGE [IBGE00029499], RB [RB00686263] • Paraty; 27 Apr. 1993; Marquete 804; RB [RB00054133] • Paraty; 8 Jun. 2006; Silva-Castro 1022; HUEFS [HUEFS110123], HUESB [HUESB00003384] • Petrópolis; Aug. [year unknown]; Dionisio 828; RB • Petrópolis; Feb. 1966; Duarte 9676; RB [RB00054212, RB1296204] • Petrópolis; Aug. [year unknown]; Góes 828; RB [RB00054251] • Petrópolis; 30 Jun. 1943; Góes 204; RB [RB00054032] • Petrópolis; 5 Sep. 1977; Mautone 392; RB [RB00302862] • Piraí; 7 Oct. 1988; Barbosa 1049; HRCB, RB [RB00004798], UEC • Resende; 9 Apr. 1928; Kuhlmann 212; RB [RB00533450] • Rio das Ostras; Mar. 2006; Oliveira 922; RB [RB00485298] • Rio das Ostras; Mar. 2006; Oliveira 928; RB [RB00515619] • Rio de Janeiro; 9 Apr. 1970; Caroche 2; RB • Rio de Janeiro; 18 Oct. 1931; Cruz 32; R • Rio de Janeiro; 28 Sep. 1964; Flaster 1154; R • Rio de Janeiro; 1951; Heringer s.n.; RB • Rio de Janeiro; 17 May 1930; Kuhlmann 1695; RB • Rio de Janeiro; 3 Aug. 1931; Kuhlmann s.n.; RB • Rio de Janeiro; 14 Jul. 1920; Kuhlmann s.n.; RB • Rio de Janeiro; 3 Aug. 2015; Mattos 157; RB [RB00990397] • Rio de Janeiro; 21 Dec. 1999; Nunes 326; R • Rio de Janeiro; 13 May 1945; Occhioni 131; RB [RB00054051], RFA [RFA00034275] • Rio de Janeiro; 12 Jul. 1946; Occhioni 589; RB [RB00054125] • Rio de Janeiro; 23 Feb. 1959; Pereira 4488; RB [RB00054202] • Rio de Janeiro; 22 Aug. 2000; Santos s.n.; RB • Rio de Janeiro; 28 Jul. 1957; Souza s.n.; RB • Rio de Janeiro; 28 May 1958; Sucre 3827; RB • Rio de Janeiro; 4 Jan. 1969; Sucre 4302; RB [RB00054174] • Rio de Janeiro; 4 Nov. 1969; Sucre 4312; RB [RB00054121] • Rio de Janeiro; 9 Apr. 1970; Sucre 6600; RB [RB00054211] • Rio de Janeiro; 1 Dec. 1971; Sucre 8020; RB [RB00054147] • Rio de Janeiro; 19 Apr. 1972; Sucre 8843; MO [MO081859], RB [RB00054149] • Rio de Janeiro; 9 Aug. 1958; Pereira 16; R • Silva Jardim; 6 Sep. 2012; Pace 229; SPF [SPF00212041] • Silva Jardim; 6 Sep. 2012; Pace 230; MO, SPF [SPF00212042]. – São Paulo • Caraguatatuba; 29 Jun. 1956; Kuhlmann 3838; SP [SP058035] • Ilhabela; 26 Mar. 1990; Souza 3175; ESA • Ubatuba; 21 Oct. 2006; Aranha 352; UEC [UEC139370] • Ubatuba; 21 Oct. 2006; Aranha 353; UEC [UEC139371] • 2 Jul. 2007; Luize 2; HRCB.

 Nomenclatural notes

Here we recognize A. comosum as a valid species and remove the taxon as a synonym of A. acutissimum. We also remove the taxa A. nitidum and A. comosum var. lanceolatum as synonyms of A. acutissimum and transfer them to A. comosum, following the new species delimitation. The recognition of A. comosum does not change the status of the former basionym Bignonia comosa Cham., which is an illegitimate name as stressed by Turner (2015).

 Taxonomic notes

Adenocalymma comosum resembles morphologically both A. acutissimum and A. grandifolium Mart. ex DC. and can be recognized by the presence of the lianescent habit (vs shrubby in A. grandifolium), prophylls falcate (vs straight in A. grandifolium), inflorescence axes, bracts, bracteoles, and calyx indument drying dark brown (vs drying cinereous in A. acutissimum and ferruginous in A. grandifolium), bracts and bracteoles conspicuous (i.e. ≥ 12 mm long) (vs reduced in A. grandifolium, < 12 mm long), corolla yellow and infundibular (vs pale yellow and tubular in A. grandifolium), and anthers and stigma included in the corolla tube (vs exserted or at the corolla mouth) (Table 1). The characters described for A. comosum are shared with A. nitidum and A. comosum var. lanceolatum, justifying a circumscription of A. comosum including these taxa as synonyms.

Morphological comparison among Adenocalymma acutissimum, A. comosum, and A. grandifolium.

Characters A. acutissimum A. comosum A. grandifolium
Habit Liana Liana Scandent shrub
Prophyll shape Falcate Falcate Straight
Inflorescence axes, bracts, bracteoles, and calyx indumentum Drying cinereous Drying dark brown Drying ferruginous
Bracts and bracteoles Conspicuous (≥ 12 mm) Conspicuous (≥ 12 mm) Reduced (< 12 mm)
Corolla colour Yellow Yellow Pale yellow
Corolla shape Infundibular Infundibular Tubular

The importance of the inflorescence axes, bracts, bracteoles, and calyx indument as a relevant character to separate A. acutissimum and A. comosum is highlighted by the phylogenomic results obtained for Adenocalymma. Both species were sampled (A. acutissimum as A. acutissimum2 – voucher Monguillot 149, SPF – and A. comosum as A. acutissimum1 – voucher Fonseca 208 SPF) and they emerged in different lineages within the Atlantic Forest clade and were never recovered as sister species using plastid, mitochondrial, or nuclear genomes (Fonseca and Lohmann 2018, 2020, in prep.; Fig. 1).

Geographically, A. comosum and A. grandifolium are partially sympatric, occupying the same ombrophilous forests, with A. grandifolium reaching up to 1200 m elevation in “Serra da Mantiqueira.” Adenocalymma acutissimum can be found in the ombrophilous Atlantic Forest remnants in the states of Rio de Janeiro and São Paulo, being more common on the slopes of “Serra do Mar.” Possible sympatric populations of both species can occur close to the border between the states of Rio de Janeiro and São Paulo, with individuals of both A. acutissimum and A. comosum found in the same municipalities (Fig. 2).

 Plantae Lamiales Bignoniaceae 2D83EB6C-6941-588F-80AD-BE885B40586F Adenocalymma darwinii urn:lsid:ipni.org:names:77374059-1 L.H.Fonseca sp. nov. Figs 1 , 2 , 3 , 4 , Table 2 Type

BRAZIL – Espírito Santo • Santa Teresa, Cabeceira do 25 de Julho; 17 Aug. 2005; fl.; Kollmann 8228; holotype: MBML [MBML00009099]; isotype: SPF [SPF00199077].

10.5091/plecevo.172513.figure3 AA9449C0-D039-500C-8A58-04E1F72D590B

Adenocalymma darwinii. A. Habit. B. Young branch. C. Old branch. D–E. Young branches covered with trichomes. F. Leaves. G–I. Inflorescence. Photos by Ricardo Ribeiro.

https://binary.pensoft.net/fig/1505339 Diagnosis

Adenocalymma darwinii resembles A. hirtum (Mart. ex DC.) Bureau & K.Schum. and A. salmoneum J.C.Gomes. It shares with A. hirtum the hirsute indumentum on the branches, petioles, petiolules, major veins of the leaflets, inflorescence axis, bracts, bracteoles, and calyx. However, it can be differentiated by the presence of slightly gibbous corolla with narrow aperture, and exserted anthers and stigma. It shares with A. salmoneum the slightly gibbous corolla with narrow aperture, cupular trichomes at the apex of the corolla, and exserted anthers and stigma. However, it can be differentiated by the scandent shrub-like habit (vs lianescent), the hirsute indumentum on the branches, petioles, petiolules, major veins of the leaflets, inflorescence axis, bracts, bracteoles, and calyx (vs glabrous), linear bracts (vs elliptic), yellow corolla (vs orange), and the anthers and stigma exserted or at the corolla mouth (vs included in the corolla tube).

10.5091/plecevo.172513.figure4 4428802E-CDBC-59EC-A18B-4C15B30C353F

Adenocalymma darwinii. A. Flowering branch. B. Leaf. C. Detail of trichomes. D. Flower. E. Detail of corolla trichomes. F. Bracteole. G. Detail of calyx. H. Detail of calyx trichomes. I. Opened flower. J. Nectar disk, ovary, style, and stigma. K. Detail of stigma. Illustrated from Kollmann 8228 (SPF) by Klei Souza.

https://binary.pensoft.net/fig/1505340 Description

Shrub to scandent shrub, up to 3.5 m tall. Stems terete, brown, with striated bark, with elliptic lenticels; branchlets terete, hirsute, with eglandular trichomes simple or rarely branched, interpetiolar region without glandular fields; prophylls of the axillary buds narrow-elliptic, 9 × 1.3 mm, hirsute, with eglandular trichomes simple, with glandular trichomes cupular, ca 0.5 mm diam. Leaves 3-foliolated, with the terminal leaflet not modified into a tendril; petioles 10.1–75.6 mm long; petiolules terete, with variable lengths, central petiolules ca 57 mm long, lateral petiolules ca 3 mm long, hirsute; leaflets elliptic or slightly obovate, apex acuminate to acute, base cuneate, symmetric, blade membranous, adaxial surface glabrous to slightly hirsute, with eglandular trichomes simple, abaxial surface hirsute with more trichomes on the veins, with eglandular trichomes simple, with glandular trichomes cupular sparsely distributed, first venation order pinnate, second venation order brochidodromous, third venation order reticulate, margins entire, straight, leaflets 10–24.1 × 2.3–7.0 cm. Inflorescence a branched lateral raceme, congested, main axis and pedicels hirsute, with eglandular trichomes simple or rarely branched; pedicels up to 4.8 mm long; floral bracts caducous, or covering young buds, linear, chartaceous, 9.2 × 2 mm, hirsute, with eglandular trichomes simple and glandular trichomes cupular, ca 0.8 mm diam.; bracteoles caducous, persistent covering the buds, linear, membranous, 4.8–10.2 × 0.8 mm, with glandular trichomes, ca 0.4 mm diam. Calyx green, campanulate, 5-lobed, coriaceous, 8.9–11 × 6–7.5 mm, hirsute, with eglandular trichomes simple or branched, with glandular trichomes cupular, 0.5–0.7 mm diam. Corolla yellow, tubular to slightly gibbous, membranous, with nectar guides, 33–50.2 mm long, 8–9 mm at the portion of maximum width, 2 mm wide at the base, pubescent, with eglandular trichomes, and cupular trichomes at the apex, lobes orbicular, 3.0 × 5 mm diam. Androecium attached at 10.2 mm from the base, shorter filaments 45 mm long, longer filaments 62 mm long, staminode ca 4 mm long, glabrous, hirsute at insertion, with glandular trichomes stipitate, anthers 6 × 0.8 mm, exserted. Gynoecium ca 32–64 mm long; ovary cylindrical, 3.2 × 1.4 mm, glabrous; style ca 61 mm long, glabrous; stigma lanceolate, 2.3 × 1.5 mm, exserted. Fruit unknown.

 Distribution and ecology

Adenocalymma darwinii is only known from the type locality in Espírito Santo state, Brazil (Fig. 2). This species is found in the understory of seasonally semi-deciduous Atlantic Forest remnants.

 Phenology

The species was collected bearing flowers in August and September.

 Etymology

We are describing Adenocalymma darwinii to celebrate the great British naturalist, Dr Charles Darwin. Known as one of the fathers of the theory of evolution by natural selection and the author of the book On the Origin of Species. His discoveries and insights inaugurated a new perspective on how biodiversity is perceived and understood. This tribute is also a reminder of the importance of his ideas and how influential they remain.

 Preliminary IUCN conservation assessment

The species is only known from the type locality. Its conservation status is Data Deficient (DD) according to the IUCN criteria (IUCN 2012; IUCN Standards and Petitions Subcommittee 2017) until more information about this new species is gathered during field studies and more populations are found. Meanwhile, the reduced population size and the anthropogenic pressure (see Fraga et al. 2019) at the only known locality would likely push this species towards extinction if conservation measures are not taken.

 Additional material examined (paratypes)

BRAZIL – Espírito Santo • Santa Teresa, Cabeceira do 25 de Julho, 19°50’19.2”S, 40°36’35.0”W; 302 m; 11 Sep. 2024; fl.; Ribeiro 800; VIES • Sítio Recanto Feliz; 11 Aug. 2005; fl.; Fontana 1656; MBML [MBML00008654].

 Taxonomic notes

The state of Espírito Santo in Brazil has 16 species of Adenocalymma (Fonseca and Lohmann 2019a); however, A. darwinii is the only one with a hirsute indumentum and clearly differs from the morphologically similar A. hirtum by being a scandent shrub (vs liana), and by the presence of tubular corolla (vs infundibular) and exserted anthers and stigma (vs included in the corolla tube). Adenocalymma darwinii also differs from A. salmoneum by being a scandent shrub (vs liana) and by its yellow corolla (vs orange) (Table 2). Adenocalymma darwinii was included in the phylogenetic study and emerged as sister to A. apetiolatum L.H.Fonseca & L.G.Lohmann (Fonseca and Lohmann 2018; Fig. 1). The latter species is also an endemic of seasonally semi-deciduous Atlantic Forest remnants in Espírito Santo, however, markedly differs from A. darwinii due to the presence sessile leaves and gibbous corollas.

Morphological comparison among Adenocalymma darwinii, A. hirtum, and A. salmoneum.

Characters A. darwinii A. hirtum A. salmoneum
Habit Scandent shrub Liana Liana
Indumentum Hirsute Hirsute Glabrescent to pubescent
Bracts Linear Linear Elliptic
Corolla colour Yellow Pale yellow Orange
Corolla shape Tubular to slightly gibbous Infundibular Tubular to slightly gibbous
Cupular trichomes at the apex of corolla Present Absent Present
Anther and stigma position Exserted or at the mouth Included Exserted or at the mouth
Discussion

The taxonomic updates provided here contributed to eight new species (Udulutsch et al. 2013; Fonseca et al. 2016; Fonseca and Lohmann 2017, 2019b; this study) and one new circumscription (Gomes et al. 2020) recently published for Adenocalymma. All these taxa are endemic to the Atlantic Forest, highlighting the importance of this biome for plant biodiversity. The Atlantic Forest is a globally critical biodiversity hotspot, renowned for its extraordinary levels of plant endemism and species richness. Despite being reduced to fragments of its original extent, it harbours an estimated 15,000 plant species, over half of which are found nowhere else on Earth, a testament to its unique evolutionary history (Brazilian Flora Group 2018). This high concentration of endemic flora, including countless tree species, epiphytes – like orchids and bromeliads – and rare medicinal plants, provides the foundational structure for an immense associated diversity of fauna and ecosystem services. Its severe threat level, recognized by its designation as a biodiversity hotspot (Myers et al. 2000), means the conservation of its remaining fragments is not just a national priority for Brazil but an international imperative to safeguard this irreplaceable genetic reservoir against extinction.

The morphological study of the genus Adenocalymma is an ongoing effort towards the first monograph of the genus in more than a century (Schumann 1894). Dramatic changes in taxonomic circumscription (Lohmann and Taylor 2014; Fonseca and Lohmann 2019b) were necessary in Adenocalymma, all supported by new phylogenetic findings using Sanger generated sequences of plastid and nuclear markers (Lohmann 2006), complete plastomes (Fonseca and Lohmann 2018, 2019b), and hundreds of nuclear markers (Fonseca and Lohmann in prep.). Given the robustness and congruence of the phylogenetic results, the major taxonomic changes within Adenocalymma are probably in the past and we can now focus on fine-tuning the species taxonomy. These efforts resulted in the taxonomic changes and the new species described here.

 Acknowledgements

The authors thank the VIES, MBML, and SPF herbaria, and the VIES herbarium technician Dr Luana Calazans for the support of curation and herborization of the botanical samples. LHMF thanks CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior) and CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico) for graduate and postdoctoral fellowships. RSR thanks Flávia Chaves for logistical support and transportation to collect samples in the field. RSR also thanks CAPES for fellows’ master’s level (Process: 88887.658974/2021-00) and SISBIO authorization (82167-3, 57107/2).

 References Brazilian Flora Group (2018) Brazilian Flora 2020: innovation and collaboration to meet Target 1 of the Global Strategy for Plant Conservation (GSPC).Rodriguésia69: 1513–1527. https://doi.org/10.1590/2175-7860201869402 ChamissoA de (1833) De plantis in Expeditione Romanzoffiana et in herbariis regiis observatis disserere pergitur. Bignoniaceae.Linnaea7(6): 689–723. CandolleAP de (1845) Bignoniaceae. In: CandolleAP de (Ed.) Prodromus, vol.9(5). Masson, Paris, 142–248. FonsecaLHMLohmannLG (2017) Adenocalymma cauliflorum (Bignonieae, Bignoniaceae), a new cauliflorous species from the Atlantic Forest of eastern Brazil.Systematic Botany42: 584–589. https://doi.org/10.1600/036364417X696078 FonsecaLHMLohmannLG (2018) Combining high-throughput sequencing and targeted loci data to infer the phylogeny of the “Adenocalymma-Neojobertia” clade (Bignonieae, Bignoniaceae).Molecular Phylogenetics and Evolution123: 1–15. https://doi.org/10.1016/j.ympev.2018.01.023 FonsecaLHMLohmannLG (2019a) An updated synopsis of Adenocalymma (Bignonieae, Bignoniaceae): new combinations, synonyms, and lectotypifications.Systematic Botany44: 893–912. https://doi.org/10.1600/036364419X15710776741341 FonsecaLHMLohmannLG (2019b) A new species of Adenocalymma (Bignonieae, Bignoniaceae) from Minas Gerais, Brazil.Brittonia71: 183–189. https://doi.org/10.1007/s12228-018-9552-2 FonsecaLHMLohmannLG (2020) Exploring the potential of nuclear and mitochondrial sequencing data generated through genome‐skimming for plant phylogenetics: a case study from a clade of neotropical lianas.Journal of Systematics and Evolution58: 18–32. https://doi.org/10.1111/jse.12533 FonsecaLHMZuntiniARLohmannLG (2016) Two new species of Adenocalymma (Bignonieae, Bignoniaceae) from the Atlantic Forest of Brazil.Phytotaxa284: 263–272. https://doi.org/10.11646/phytotaxa.284.4.2 FragaCNFormigoniMHChavesFG (2019) Fauna e Flora Ameaçadas de Extinção no Estado do Espírito Santo. Instituto Nacional da Mata Atlântica, Santa Teresa, 1–432. GomesBMFonsecaLHMLohmannLG (2020) Adenocalymma albiflorum (Bignonieae, Bignoniaceae), a new combination, notes on morphology and distribution.Brittonia72: 317–323. https://doi.org/10.1007/s12228-020-09622-z HijmansR (2025) terra: Spatial Data Analysis. R package version 1.8-74. https://rspatial.org/ [accessed 30.10.2025] IBGE (2020) Brasil: Mapas de referência - Mapas Políticos – 1:2,500,000. Instituto Brasileiro de Geografia e Estatística. https://www.ibge.gov.br/pt/inicio.html [accessed 25.12.2024] IUCN (2012) IUCN Red List categories and criteria. Version 3.1. Second edition. IUCN, Gland & Cambridge. https://www.iucnredlist.org/resources/categories-and-criteria [accessed 25.12.2024] IUCN Standards and Petitions Subcommittee (2017) Guidelines for using the IUCN Red List categories and criteria, version 13. https://nc.iucnredlist.org/redlist/content/attachment_files/RedListGuidelines.pdf [accessed 25.12.2024] LohmannLGTaylorCM (2014) A new generic classification of Bignonieae.Annals of the Missouri Botanical Garden99: 348–489. https://doi.org/10.3417/2003187 LohmannLG (2006) Untangling the phylogeny of neotropical lianas (Bignonieae, Bignoniaceae).American Journal of Botany93: 304–3018. https://doi.org/10.3732/ajb.93.2.304 MyersNMittermeierRAMittermeierCGFonsecaGABKentJ (2000) Biodiversity hotspots for conservation priorities.Nature403(6772): 853–858. https://doi.org/10.1038/35002501 PebesmaE (2018) Simple Features for R: Standardized Support for Spatial Vector Data.The R Journal10(1): 439–446. https://doi.org/10.32614/RJ-2018-009 PebesmaEBivandR (2023) Spatial Data Science: with Applications in R. Chapman and Hall/CRC. https://doi.org/10.1201/9780429459016 RadfordAEDickisonWCMasseyJRBellCR (1974) Vascular Plant Systematics. Harper & Row, New York, 1–891. R Core Team (2025) R: a language and environment for statistical computing. Version 4.4. R Foundation for Statistical Computing, Vienna. https://www.r-project.org/ [accessed 30.10.2025] RoxburghW (1832) Flora Indica, or Description of Indian Plants, vol. 3. Printed for W. Thacker, Serampore, 1-849. SchumannK (1894) Bignoniaceae. In: EnglerAPrantlK (Eds) Die natürlichen Pflanzenfamilien, Teil 4 (Abt.3b). W. Engelmann, Leipzig, 189–252. SchumannK (1896) Adenocalymma. In: MartiusCFP de (Ed.) Flora Brasiliensis, vol.8(2). F. Fleischer, Leipzig, 87–120. ThiersB (2025) Index Herbariorum: a Global Directory of Public Herbaria and Associated Staff. New York Botanical Garden’s Virtual Herbarium. https://sweetgum.nybg.org/ih/ [accessed 24.02.2025] TurnerIM (2015) The correct name for Adenocalymma comosum (Bignoniaceae).Phytotaxa222: 167–168. https://doi.org/10.11646/phytotaxa.222.2.13 UdulutschRGMAssisMADiasP (2013) Taxonomic update of Adenocalymma (Bignoniaceae): emendations, new synonyms, typifications, and status change.Turkish Journal of Botany37: 630–643. https://doi.org/10.3906/bot-1207-55