Three new Nicotiana species (Solanaceae) from Southern Brazil

Abstract

Nicotiana belongs to the Solanaceae and comprises 105 species, most of which are found in the Americas. In Brazil, 10 species are traditionally recognized, or 13, according to this study. All native Brazilian species occur in the South and Southeast regions. Despite previous taxonomic studies, new species continue to be discovered, including N. mutabilis and N. gandarela. In this context, we have discovered three distinct morphologies in southern Brazil and propose them as new species: N. litoranea, morphologically similar to N. alata; N. crux-australis and N. petum, both morphologically related to N. forgetiana. Additionally, the three new species were preliminarily evaluated as threatened with extinction.

Keywords:
Alatae; Atlantic Forest; Endemic species; Taxonomy

Introduction

Nicotiana L. (Solanaceae) comprises 105 species classified into 13 sections (Knapp et al., 2004; Knapp, 2020; Chase et al., 2022; Chase et al., 2023; POWO, 2024). The genus is most diverse in the Americas, with two centers of diversity: one in the Andean region and one in Australia (Goodspeed et al., 1954; Dupin et al., 2017; Chase et al., 2018). Furthermore, there is one Nicotiana species in Namibia (Africa) and one in the Melanesian region (Goodspeed et al., 1954; Hunziker, 1979; 2001; Knapp, 2020).

Nicotiana is a thoroughly researched genus, with extensive molecular phylogenies reported at the generic level (Aoki & Ito, 2000; Chase et al., 2003; Clarkson et al., 2004; Clarkson et al., 2017) and some literature on its systematics and taxonomy, with a particular emphasis on South American and Brazilian taxa (Sendtner, 1846; Goodspeed et al., 1954; Smith & Downs, 1964; 1966; Knapp, 2020; Stehmann et al., 2002; Knapp et al., 2004; Vignoli-Silva & Mentz, 2005; Dupin et al., 2017; Chase et al., 2018; Vignoli-Silva & Stehmann, 2020; Augsten et al., 2022). Despite these taxonomic studies, most research on Nicotiana has focused on N. tabacum L., a globally cultivated species that likely originated in the Andes and northwestern Argentina. It is economically relevant in the tobacco industry for the production of cigars, cigarettes, and medicines (Knapp, 2020; Sierro & Ivanov, 2020).

Brazil harbors ten species of Nicotiana, eight of which are native to grasslands, rock outcrops, and forests, and also occurs in anthropogenic habitats such as pastures and croplands, primarily distributed in the South and Southeast regions, with only Nicotiana bonariensis Lehm. reaching the Northeast region (Vignoli-Silva & Stehmann, 2020). The other two species, N. tabacum and N. glauca Graham, are exotic to Brazil (Vignoli-Silva & Stehmann, 2020; Augsten et al., 2022). The native Nicotiana species that occur in Brazil belong to Nicotiana sect. Alatae Goodspeed (Knapp et al., 2004; Augsten et al., 2022). These species are characterized by their herbaceous habit, rosulate and sessile leaves that are usually covered by sticky hairs, few leaves on the top stems, and an abrupt dilatation at the throat of the corolla tube (Goodspeed et al., 1954, Knapp et al., 2004).

With the addition of the newly described species mentioned here, as well as N. gandarelaAugsten & Stehmann (Augsten et al., 2022) and a potential new species derived from N. forgetiana Hort. ex Hemsl (mentioned by Teixeira et al., 2021 but not yet formally described), the total number of native Nicotiana species in Brazil has nearly doubled in the past three years. This includes the rediscovery of the rare and narrow endemic Nicotiana azambujae L.B.Sm & Downs from Santa Catarina state (Smith & Downs, 1966; Funez et al., 2023). These findings confirm that Nicotiana is more diversified and intricate than previously believed, and the effort to understand its taxonomic and ecological elements must continue.

To address gaps in knowledge about the Nicotiana genus, we describe three newly discovered species, evaluate their conservation status, and provide field photographs, a distribution map, and a comparative table with their morphologically closest species. We also update the identification key of Augsten et al. (2022) for Brazilian species in the Alatae section to include the new species.

Material and Methods

The morphological descriptions of the new species were based on field observations and the examination of specimens from the FLOR, FURB, HBR, and HLS (incorporated into HBR) herbaria. Additionally, images of specimens from the ALCB, BHCB, EAC, ECT, ESA, G, HLS, HUCP, HUEFS, IAN, ICN, K, MBM, MBML, MO, NY, P, RB, SP, UEC, UPCB, and US herbaria were also studied. All acronyms are listed following Thiers (2024 - continuously updated). The morphological description terminology follows Vignoli-Silva & Stehmann (2020). The vernacular names were proposed based on the recommendations of Marinho & Scatigna (2022). The photos of flower details were captured using a stereomicroscope, and the field photos were captured using digital cameras. The maps were created using the QGIS software (GIS Development Team, 2023). The Area of Occupancy (AOO) and Extent of Occurrence (EOO) were determined using GeoCat (Bachmann et al., 2011), using the standard square measurement recommended by IUCN (2012; 2019) of 2 × 2 km. The conservation status of the species was evaluated using the IUCN (2012; 2019) criteria.

Results and discussion

Taxonomy

Nicotiana crux-australis Funez sp. nov. Type: BRAZIL, Santa Catarina: Penha, near São Miguel river, restinga, 48º37'12.64" W, 26º49'32.89" S, 16 m, 15 January 2012 (fl, fr), L.A. Funez 177 (holotype: FURB37569!) (Figs. 1, 2A).

Figure 1.
Field photographs of Nicotiana crux-australis. A. Corolla in frontal view. B. Corolla in lateral view, showing the tube. C. Fruits. D. Basal leaves. E. Habit. Author: Luís Adriano Funez.

Figure 2.
Dissected flowers of Nicotiana crux-australis and N. petum, showing the insertion of the stamens on the corolla tube. A red triangle marks the point of insertion. A. Nicotiana crux-australis. B. Nicotiana petum.

Diagnosis

Nicotiana crux-australis resembles N. petum Funez sp. nov., which presents corolla tubes reaching 17-26 mm long (vs. tubes 14-18 mm long), limbs 7.4-9.7 mm long and 16-20 mm diam., zygomorphic with obtuse-angulose lobes (vs. limbs 3-5 mm long and 8-10 mm diam., slightly zygomorphic with rounded-obtuse lobes), and winged stems (vs. not winged stems).

Description

Herbs, probably annual or biannual, up to 0.7 m tall. Stems erect, glandular-pubescent, with stalked, multicellular, capitate glandular trichomes (all other trichomes referred to as glandular-pubescent are the same type as these), internodes not winged, elongate, and erect when flowering, branching, forming a paniculate inflorescence. Basal leaves petiolate, petiole 15-34 mm long, decurrent, not auriculate, oblong to oblanceolate, 9.5-11 cm (9.5-15 with petioles) × 4-6.1 cm, membranaceous, sparsely glandular-pubescent, stem leaves oblanceolate, 3.3-10 cm × 0.6-3.2 cm, gradually diminishing towards the apical portion of the stems. Inflorescence paniculate, 21-38 cm long. Flowers, pedicels 0.7-5 mm long, densely glandular-pubescent. Calyx campanulate, glandular-pubescent, deep lobate, 7-9 mm long, the tube 4.6-6.0 mm, the lobes linear-lanceolate, the two dorsal lobes longer than the others. Corolla cream-white, hippocraterifom, sparsely glandular externally, glabrous internally, 24-30 mm long, tube 14-18 mm long, apically ventricose, limb 3-5 mm long and 8-10 mm diam., slightly zygomorphic. Stamens subequal, inserted on the basal portion of the tube, filaments 20 mm long; adnate ca. 3.4 mm from the base of corolla tube, one curved and four geniculate at the insertion; filaments glabrous on its free portion, densely sericeous-pilose on the adnate portion; anthers cream-colored, rounded, 1.3-1.4 mm. Pollen cream-colored. Style 8 mm long, apex capitate. Ovary glabrous obconic, 1.8 mm × 0.7 mm. Capsule ovoid 7.2-8.4 mm × 4.3-5.2 mm, apex acute, glabrous. Seeds rounded-elliptic, 0.60-0.66 mm diam., brown, testa reticulate, hexagonal and anticlinal walls ondulate.

Etymology

Its beautiful white flowers at night can be perceived as resembling a constellation. Thus, “Crux-australis” is a reference to the Southern Cross constellation, one of the brightest in the southern hemisphere's night sky.

Distribution and ecology

Nicotiana crux-australis is found in three municipalities in the state of Santa Catarina: Balneário Camboriú, Botuverá, and Penha (Fig. 3). This species grows in direct sunlight, specifically on rocky outcrops or dunes, at elevations ranging from sea level to around 300 meters above sea level. The white flowers exhibit diurnal anthesis, suggesting a lack of specialization in attracting sphingophilous pollinators, unlike other sphingophilous species such as N. alata Link & Otto, N. longiflora Cav., and N. litoranea Funez sp. nov.

Figure 3.
Distribution map of N. crux-australis, N. litoranea and N. petum.

Blooming and Fruiting

Herbarium records indicate that N. crux-australis blooms and produces fruit in January and May. Our field findings, on the other hand, suggest that this species typically blooms and produces fruits from November to May. Fruiting stalks can persist throughout the winter (June to September), but the maturation of the fruits is rapid and synchronizes with the blooming period.

Examined specimens: Santa Catarina. Balneário Camboriú, Laranjeiras, on rocky shore, 48º38'05" W, 26º59'26” S, 10 January 2018 (fl, fr), L.A. Funez & A.E. Zermiani 7025 (FURB57788); Botuverá, Reserva Biológica Estadual da Canela Preta, Cachoeira do Bego, paredão da cachoeira, 49º06'55" W, 27º15'49" S, 600 m, 6 May 2021 (fl, fr), A. Kassner-Filho & N.M. Rocha 6480 (FURB68630); Penha, Praia da Galheta, on rocky shore , 48º36'05" W, 26º49'21" S, 3 m alt. 12 January 2023 (fl, fr), L.A. Funez et al. 9930 (HBR61022); Praia das Pacas, on the sand dunes, near a rocky shore, 48º36'13" W, 26º49'33" S, 2 m alt. 10 January 2023 (fl, fr), L.A. Funez et al. 9931 (HBR61023).

Conservation status

According to the B2 criteria of IUCN, the species was assessed as Endangered (EN-B2a,b[iii]). This species is only known from three locations: Praia Vermelha fragment, in Penha, which concentrates most of the samples; Laranjeiras, in Balneário Camboriú; and Cachoeira do Bego, in Botuverá, which is the only record inside a conservation unit, the Reserva Biológica da Canela Preta. According to our analysis, this species has an area of occupancy (AOO) of only 16 km² and an extent of occurrence (EOO) of 570 km². The Atlantic Forest loss in area and quality in Santa Catarina state is very worrying, from 1985 to 2023 the state lost 8% of its original covering, and in the last decade, the deforestation area increased from 569 ha to 1.113 ha, according to the data published in MapBiomas (2025).

Suggested vernacular name

The suggested vernacular name for the species is "fuminho-branco", which translates to “small white-flowered tobacco" in Portuguese, the official language of the species' native country. The term refers to the white blossoms and low stature of the plant.

Comments

This species resembles a white form of N. forgetiana Hemsl. but differs in several key characteristics. Nicotiana crux-australis has white flowers (vs. pink, purple, or red, rarely white- which is probably a misidentification of both N. crux-australis and N. petum- in N. forgetiana). Its stems are not winged (vs. winged stems in N. forgetiana), anthers cream-colored (vs. anthers purple-colored), shorter capsules 7-8.4 mm long, (vs. longer capsules 9-12 mm long.), seeds brownish-gray with dull testa (vs. seeds with shiny reddish-brown testa).

This species shares some similarities with N. petum due to its whitish corolla. However, the corolla tube of N. crux-australis is shorter 14-18 mm long (vs. 17-26 mm long in N. petum); additionally, in N. crux-australis, the corolla limbs are whitish-cream, 8-10 mm diam., with rounded-obtuse lobes (vs. pure white, 16-20 mm diam., with obtuse-angulose lobes)

Plants of N. crux-australis are small herbs with non-winged stems, up to 0.7 m tall with few (1-4) flowering branches (vs. more robust with winged stems, reaching 1.5 m tall with very branched flowering stems in N. petum) (Table 1).

Table 1.
Comparative table between the new species (N. crux-australis, N. litoranea and N. petum) and its morphologically related species (N. alata, N. forgetiana, N. langsdorffii and N. longiflora).

Species	Stems	Corolla (color)	Corolla (lenght)	Corolla limb	Stamens adnation	Pollen (color)
N. alata	Erect, winged	White, pink	30-100 mm	Strongly zygomorphic, deeply lobed, 15-35 mm diam.	4 (longer, geniculate) +1 (shorther not geniculate), adnate on the upper part of the tube	Cream
N. crux-australis	Erect, not winged	White	24-30 mm	Weakly zygomorphic, weakly lobed, 8-10 mm diam.	4 (geniculate)+1 (curved), adnate on the lower part of the tube	Cream
N. forgetiana	Erect, winged	Pink, red, purple, magenta	15-45 mm	Weakly zygomorphic, weakly lobed, 12-25 mm diam.	4 (geniculate)+1 (curved), adnate on the lower part of the tube	Cream
N. langsdorffii	Erect, winged	Greenish Yellow	20-40 mm	Weakly zygomorphic, almost radial, weakly lobed to almost entire 5-10 mm	4 basally inserted (curved) +1 shorter and inserted forward, (straight)	Blue
N. litoranea	Acaulescent	White	44-48 mm	Weakly zygomorphic, deeply lobed, 18 mm diam.	4 (longer, n) +1 (shorther) not geniculate, adnate on the lower part of the tube	Yellow
N. longiflora	Acaulescent	White	35-105 mm	Weakly zygomorphic, deeply lobed, 12-30 mm diam.	All inserted on the upper half of the tube: 2 slightly more basal with longer filaments + 2 more slightly more distal with shorter filaments + 1 basal with the longer filament. All filaments straight.	Cream
N. petum	Erect, winged	White	28-31 mm	Strongly zygomorphic, weakly lobed, 16-20 mm diam.	4 (geniculate)+1 (curved), adnate on the lower part of the tube	Cream

Nicotiana crux-australis does not occur sympatrically with any other Nicotiana species. Eventually, N. longiflora is spotted as a ruderal species near some localities where N. crux-australis inhabits, ca. 1-5 km from the N. crux-australis populations in Penha municipality. Nicotiana forgetiana, its morphologically closest species, is found on basaltic rocky outcrops of Aparados da Serra Geral region, 800-1.800 m asl, and N. crux-australis is found at sea level up to ca. 300 m asl, on granitic rocky outcrops.

Nicotiana litoranea Funez sp. nov. Type: BRAZIL, Santa Catarina: Florianópolis, Trilha das cavernas da Praia do Pântano do Sul, 48º30'16" W, 27º47'28" S, 5 m alt. 27 December 2022 (fl, fr), F.M.H. Riella & A.G. Martins 10 (holotype: HBR61021!) (Fig. 4).

Figure 4.
Field photographs of Nicotiana litoranea. A. Corolla in frontal view. B. Corolla in lateral view. C. Fruits. D. Leaves and habit. Author: Fabrício Mil Homens Riella

Diagnosis

Similar to Nicotiana alata. Nicotiana litoranea differs from N. alata due to the not winged stems, (vs. winged stems), very short and scarce indumentum (vs. dense and long indumentum), narrower corolla tubes, 2-3, and up to 4 mm diam. at the ventricose apical portion (3-7 mm diam., up to 10 mm on the apical ventricose portion); shorter limb, 9-10 mm, 16-18 mm diam. weakly lobed, slightly zygomorphic (vs. limb 10-15 mm long., 15-35 mm diam., deeply lobed, strongly zygomorphic, with the two basal lobes larger than the apical and stamens inserted at the apical portion of the corolla tube), weakly lobed, slightly zygomorphic; stamens inserted at the basal portion of the corolla tube (vs. stamens inserted at the apical portion of the corolla tube).

Description

Herbs, probably perennial, up to 0.4 m tall. Stem up to 25 cm tall, basally woody and thickened, with an axial taproot, flowering stems elongate, glandular-pubescent with stalked, multicellular capitate glandular trichomes (all the other trichomes referred as glandular-pubescent are the same type as these), internodes not winged, elongate and erect when flowering, branching, forming a racemose inflorescence. Basal leaves petiolate, petioles 15-20 mm long, decurrent, not auriculate, oblong to oblanceolate, 72-134 mm (with petioles) × 13-42 mm, stem leaves oblanceolate, 29-70 mm × 7-11 mm, gradually diminished to the apical portion of the stems, membranaceous, sparsely glandular-pubescent, very short (up to 0.5 mm long), margin glandular-ciliate, apex obtuse or acute and base attenuate. Inflorescence paniculate 150-180 cm long. Flowers, pedicels 6-15 mm long, densely glandular-pubescent. Calyx campanulate, glandular-pubescent, deeply lobate, 12-15 mm long, fused 6-8 mm, the lobes linear-lanceolate, the two dorsal lobes (6-8 mm long) longer than the others (3-4 mm long). Corolla cream-white, hippocraterifom, sparsely glandular-pubescent externally, glabrous internally, 52-60 mm long, tube 44-48 mm long, apically ventricose, 3-4 mm diam., limb 9-10 mm long and 18 mm diam., slightly zygomorphic. Stamens unequal, 4+1, the four longer with filaments 40-45 mm long, recurvate at the base of the anthers, the shorter stamens with filaments 32-38 mm long, inserted on the basal portion of the tube, adnate ca. 20 mm long at the corolla tube; not curved at the insertion, filaments glabrous on its free portion, densely sericeous-pilose on the adnate portion; anthers cream-colored, rounded, 1.5-2 mm × 1.5-2 mm. Pollen yellow. Style 40-42 mm long, stigma capitate. Ovary glabrous obconic, 1.8 mm × 0.7 mm. Capsule ovoid 13-15 mm × 6-7 mm, apex acute, glabrous. Seeds elliptic, ca. 1 mm × 0.5 mm, brown, testa reticulate, hexagonal, and anticlinal walls undulate.

Etymology

“Litoranea” is a reference to the habitat of this species, rocky outcrops at the seaside.

Distribution and ecology

Nicotiana litoranea is only found on Santa Catarina Island and its small neighboring islands, such as Moleques do Sul Island and Campeche Island (Fig. 3). This is a specialist species that occupies only rocky outcrops at the seaside. The fleshy consistency of the leaves in the living plant, as well as the presence of a thick stem and taproot, make it well adapted to withstand severe hydric stress and salinity (Griffiths & Males, 2017). Because the anthesis is nocturnal and the flowers are fragrant at night, we believe it is a specialized sphingophile species, like N. alata and N. longiflora.

Blooming and Fruiting

There are records of N. litoranea flowering and fruiting in November, January, and May in herbarium sheets. However, it is important to highlight that this plant most likely blooms and bears fruits during the spring and summer (October to December), leaving only the fruiting stalks during the fall and winter (May to September).

Examined specimens: BRAZIL, Santa Catarina: Florianópolis, Ilha do Campeche, Letreiro, 8 October 1983 (fl, fr), F.A. Silva-Filho 120 (FLOR5572); Ilha do Campeche, ponta norte, 26 October 1985 (fl, fr), 48º32'57" W, 27º35'48" S, 20 m, F.A. Silva-Filho 561 (FLOR15202); Ilha de Moleques do Sul, rocky coast at the top of the island, 48º25'52" W, 27º50'45" S, 24 May 2003 (fl, fr), J. Hillesheim & L.F. Machado 4 (HLS1535); hillside, 48º25'52" W,27º50'45" S, 10 November 2007 (fl, fr), O.B. Iza 609 (HLS2456); Trilha das cavernas da Praia do Pântano do Sul, 48º30'12" W, 27º47'29" S, 5 m alt. 27 December 2022 (fl, fr), F.M.H. Riella & A.G. Martins 11 (HBR61020)

Conservation status

Critically Endangered (CR-B2a,b[iii]). According to our analysis, this species has an area of occupancy (AOO) of only 20 km² and an extent of occurrence (EOO) of 51 km². As part of the delimited polygons for AOO and EOO calculations are mainly represented by the sea (ca. 70%), the real area of occupancy and extent of occurrence of this species are much smaller than presented here.

This species is only known from three islands of the Santa Catarina Island Archipelago: Santa Catarina, Campeche, and Moleques do Sul, which, except for the Santa Catarina Island, are very small islands, all belonging to Florianópolis municipality, the capital of Santa Catarina state. This municipality has very high urbanization rates, which results in high occupation pressures against the natural environment.

The populations on Moleques do Sul Island are under legal protection within the Parque Estadual do Tabuleiro. The Parque Natural Municipal da Lagoinha do Leste protects the Pântano do Sul population, leaving only the Ilha do Campeche population unprotected, but humans do not inhabit this island. Additionally, although protected areas are supposed to be perpetual, in Brazil, this cannot be taken into account when talking about conservation, since the Serra do Tabuleiro State Park itself has already had several areas that were part of its original design detached (Peres, 2019). This highlights the fragility of this system and the ease with which areas that should be designated for preservation are occupied.

Additionally, in recent years, several protected areas have had their delimitation revised, always reducing the protected areas or recategorizing them to effectively less protected areas, such as APAs (Environmental Protection Areas), which are extremely permissive regarding land use (Brasil, 2000; 2002). Protected areas such as Serra do Itajaí National Park and São Joaquim National Park are repeatedly attacked in this way by Congress. Others, whose implementation was planned, like Parque Nacional dos Campos dos Padres were promptly blocked (Zanin et al., 2009), while those that are already implemented receive minimal resources that barely support the extremely lean staff, while compensation for landowners drags on for decades, leading to conflicts and negative reactions from the population about these protected areas.

Suggested vernacular name

The suggested vernacular name for the species is “fuminho-da-praia”, which means “little beach tobacco” in Portuguese, the official language of the country where the species is native. It refers to the seaside environment in which it lives.

Comments

Due to its long white corolla tubes, this species can be misidentified as N. alata or N. longiflora. N. litoranea can be easily differentiated from N. longiflora due to the stamens inserted on the base of the corolla tube (vs. stamens inserted on the apex of the corolla tube in N. longiflora). (Fig. 5).

Figure 5.
Dissected flowers of Nicotiana litoranea, showing the insertion of the stamens on the corolla tube. The point of insertion is marked by a red triangle. A. whole tube. B. detail of the insertion of the filament.

Figure 6.
Field photographs of Nicotiana petum. A. Corolla in frontal view. B. Corolla in lateral view. C. Caulinar leaf and winged stem. D. Basal leaves. E. Habit. Author: Paulo Schwirkowski.

Nicotiana litoranea is the morphologically most similar species to Nicotiana alata, from which it can be distinguished by stems that are not winged (vs. winged stems), very short and scarce indumentum (vs. dense and long indumentum), corolla tubes narrower, 2-3 mm diam., and up to 4 mm diam. at the ventricose apical portion (vs. 3-7 mm diam., up to 10 mm on the apical ventricose portion); shorter limbs, 9-10 mm, 16-18 mm diam., weakly lobed, almost actinomorphic (vs. 10-15 mm long., 15-35 mm diam., deeply lobed, strongly zygomorphic, with the two basal lobes larger than the apical) and stamens inserted on the base of corolla tube (vs. stamens inserted on the apex of corolla tube) (Table 1).

Nicotiana litoranea does not occur in sympatry with any other species. Like most white-flowered species, this one has a strongly fragrant flower and nocturnal anthesis. During the day, the flowers remain closed. Its putative pollinators are Sphingidae moths, as recorded for N. alata (Ippolito et al., 2004).

Nicotiana petum Funez sp. nov. Type: BRAZIL, Santa Catarina: Rio Negrinho, Jardim Hantschel, fundos, along the railway line, 26º14'36" W, º49º32'04" S, 787 m, 12 October 2016 (fl, fr), P. Schwirkowski 1922 (holotype: FURB52028!). (Figs. 2B, 6).

Diagnosis

This species resembles N. crux-australis, which has corolla tubes 14-18 mm long, (vs. 17-26 mm long) limbs 3-5 mm long and 8-10 mm diam., slightly zygomorphic (vs. limbs 7.4-9.7 mm long and 16-20 mm diam., zygomorphic) and stems that are not winged (vs. winged stems).

Description

Herbs, probably perennial, up to 1.5 m tall. Stems erect, elongate, dense glandular-pubescent, internodes winged, wings up to 5 mm long, stems branching apically, forming a paniculate inflorescence. Basal leaves petiolate, petiole 5-45 mm long, decurrent, not auriculate, oblong to oblanceolate, 75-193 mm (with petioles) × 50-85 mm, stem leaves oblanceolate, 60-120 mm × 11-64 mm, gradually diminished to the apical portion of the stems, membranaceous, sparsely pubescent, with stalked, multicellular, capitate glandular trichomes (all the other trichomes referred as glandular-pubescent are the same type as these), very short (up to 0.5 mm long), margin glandular-ciliate, apex obtuse or acute and base attenuate. Inflorescence paniculate, 28-43 cm long. Flowers, pedicels 2.2-8.7 mm long, densely glandular-pubescent. Calyx campanulate, glandular-pubescent, deep lobate, 8-10.5 mm long, fused up to 3.8-5.8 mm from the basal portion, the lobes linear-lanceolate, the two dorsal lobes (4.2-6 mm long) longer than the others (1.8-3 mm long). Corolla white, hippocraterifom, sparsely glandular externally, glabrous internally, 28-31 mm long, tube 17-26 mm long, apically ventricose, 3.8-5.5 mm diam., narrowed at the base (last 3-4 mm) to 1 mm width, limb 7.4-9.7 mm long and 16-20 mm diam., slightly zygomorphic. Stamens subequal, inserted on the basal portion of the tube, filaments 17-18.8 mm long; adnate at the corolla tube 3.4 mm, one curved and four geniculate at the insertion, filaments glabrous on its free portion, densely sericeous-pilose on the adnate portion; anthers purple, rounded, 1.3-1.4 mm. Pollen cream-colored. Style 25.2 mm -26.8 mm long, apex capitate. Ovary glabrous obconic, 2.5-2.8 mm × 0.7 mm. Capsule ovoid 6.3-8.5 mm × 5.0-5.6 mm, apex acute, glabrous. Seeds elliptic, ca. 0.7 mm × 0.6 mm, brown, testa reticulate, hexagonal, and anticlinal walls undulate.

Etymology

The epithet “petum”, used here as a noun in apposition, is a Portuguese word meaning petýma, which means tobacco in the Tupi-Guarani indigenous language.

Distribution and ecology

This species is only known from a small area in the northern plateau of Santa Catarina state, in the municipalities of Mafra, Rio Negrinho, and São Bento do Sul (Fig. 3). As its geographic proximity to Paraná state, is very likely its occurrence in this state. This species inhabits open and disturbed environments, such as forest edges, roadsides, and even croplands.

Blooming and Fruiting

According to available information, this species blooms and bears fruits from October to December, but the reproductive period may extend to March-April, as with other Nicotiana sect. Alatae species. In terms of pollination patterns, we lack sufficient field data on the anthesis period and the presence or absence of floral fragrances. Furthermore, it is not possible to determine which pollinators visit N. petum.

Examined specimens: BRAZIL, Santa Catarina: Mafra, Campo Novo, 49º48'19" W, 26º06'41" S, 13 December 1995 (fl, fr), J.R. Stehmann et al. 1955 (UEC77670, MBM210201); 26º03'57" W, 49º56'19" S, J.R. Stehmann et al. 1954, 13 December 1995 (fl) (UEC77671); São Bento do Sul, Serra Alta, Vila Pilz, linha férrea, 26º17'03" W, 49º27'41" S, 850 m, 14 December 2019 (fl, fr), P. Schwirkowski 3735 (FURB65749).

Conservation status

Critically Endangered (CR-B2a,b[iii]). This species is known only from three locations, which are nearly aligned in a straight line. Our analysis indicates an area of occupancy (AOO) of only 12 km² and an extent of occurrence (EOO) of 19 km². It appears to be naturally rare, with an annual or biannual life cycle. The Atlantic Forest loss in Santa Catarina state in almost forty years, is about 8% of its original covering, in the last decade, the deforestation area increased by more than 50%, according to the data published in MapBiomas (2025). As this species inhabits open and disturbed environments, such as forest edges, roadsides, and even croplands it is especially affected by the substantial rise in herbicide usage since 1995 (Dasgupta et al., 2001; Abessa et al., 2019; Ollinaho et al., 2022), Considering this, likely, croplands and other anthropic disturbed areas are no longer suitable habitats for this species, since plant diversity decreases dramatically in areas with a history of herbicide use (Ründlof et al., 2010; Qi et al., 2020).

Suggested vernacular name

The suggested vernacular name for the species is “fuminho-do-planalto”, which means “plateau tobacco” in Portuguese, the official language of the country where the species is native. It refers to the geologic formation it inhabits, the plateau between Santa Catarina and Paraná states.

Comments

Nicotiana petum occurs sympatrically with N. bonariensis and N. langsdorffii Weinm. However, N. langsdorffii is prevalent and shares common habitats with N. petum, such as old, abandoned croplands, forest edges, and roadside areas. Conversely, N. bonariensis predominantly thrives in naturally open environments, such as high-elevation grasslands, and is occasionally observed as a ruderal herb. We have observed that the flowers of N. petum remain open during the warmest hours of the day, yet we remain uncertain about their fragrance at night. Consequently, little is known about its pollinators, indicating the need for further research to comprehend this species' reproductive biology.

Morphologically, N. petum is similar to N. crux-australis, and both resemble white forms of N. forgetiana (for taxonomy, see comments on N. crux-australis discussion and Table 1).

Updated dichotomic key to the Brazilian species of Nicotiana sect. Alatae (largely based on Augsten et al. , 2022 )

Corolla tube longer than 20 mm………………………………………….2

1’. Corolla tube up to 15 mm long…………………………………………………… 11

2. Corolla limb almost entire, greenish-yellow or light green, pollen blue………..N. langsdorffii

2’. Corolla limb deeply lobed, white, pink, purple, red or magenta, pollen white, pinkish or purple, never blue………………..3

3. Corollas changing from white to pink and magenta during the anthesis……………………………………………….N. mutabilis

3’. Corolla keeping the same color during the anthesis…….………………………………………..4

4. Corolla limbs white ………………………………………………….5

4’. Corolla limbs pink, purple, red, or magenta………………………………….10

5. Corolla tube longer than 30 mm…………………………………..6

5’. Corolla tube shorter than 30 mm………………………………...8

6. Filaments adnate to the lower portion of the corolla tube………………………………………………………………..…….N. litoranea

6’. Filaments adnate to the upper portion of the corolla tube……………………….7

7. Leaves decurrent, limb strongly zygomorphic, stamens inserted in two levels (4 higher and 1 lower) at the corolla tube, filaments all geniculate………………N. alata

7’. Leaves auriculate, not decurrent, limb weakly zygomorphic, stamens inserted in three levels (two higher, two at the middle, and one lower) at the corolla tube, filaments not geniculate…N. longiflora

8. Stamens inserted in different points, with a lower and a higher pair and the fifth stamen lower than all………………N. bonariensis

8’. Stamens inserted on the same point of the tube…………………………………….9

9. Leaves decurrent. Corolla limb 7.4-9.7 mm long………………..........N. petum

9’. Leaves not decurrent. Corolla limb 3-5 mm long…..…….N. crux-australis

10. Corolla tube longer than 30 mm, stamens adnate to the upper half of the corolla tube…………………………….N. alata

10’. Corolla tube up to 45 mm, stamens adnate do the lower half of the corolla tube……………………………….N. forgetiana

11. Stems erect, with decurrent leaves……………………………N. forgetiana

11’. Plants acaulescent or almost so, with rosulate leaves, not decurrent……………………………12

12. Corolla limbs white…………………………………………………N. bonariensis

12. Corolla limbs pink, lilac, or red………………………………………13

13. Calyx as long as the corolla tube; limb pink/lilac………………………N. azambujae

13’. Calyx shorter than corolla tube; limb red………………………………………N. gandarela

Acknowledgments

The authors thank João Renato Stehmann for greatly improving the discussion about the new species and Guilherme Salgado Grittz for the English review. ALG thanks CNPq for the productivity grant (307861/2023-6) and Fundação de Amparo à Pesquisa e Inovação do Estado de Santa Catarina (FAPESC). JGS thanks CAPES for the scholarship granted (nº 88887.902032/2023-00).

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Edited by

• Associate Editor:
  Leandro Giacomin

• Editor Chef:
  Thais Almeida

Publication Dates

• Publication in this collection
  01 Sept 2025
• Date of issue
  2025

History

• Received
  19 Oct 2023
• Accepted
  02 May 2025