Nicotiana gandarela Augsten & Stehmann, 2022

Augsten, Mariana, Meyer, Pablo Burkowski, Freitas, Loreta B., Batista, Joao A. N. & Stehmann, Joao Renato, 2022, Nicotiana gandarela (Solanaceae), a new species of ' tobacco' highly endangered from the Quadrilatero Ferrifero in Brazil, PhytoKeys 190, pp. 113-129 : 113

publication ID

https://dx.doi.org/10.3897/phytokeys.190.76111

persistent identifier

https://treatment.plazi.org/id/86855F52-FEEE-5486-9F57-EE7A14E6B00E

treatment provided by

PhytoKeys by Pensoft

scientific name

Nicotiana gandarela Augsten & Stehmann
status

sp. nov.

Nicotiana gandarela Augsten & Stehmann sp. nov.

Fig. 2 View Figure 2

Type.

Brazil. Minas Gerais. Santa Bárbara, Andre do Mato Dentro , 19°59'43"S, 43°38'39"W, 17 Apr 2018 (fl, fr), M. Augsten & J.R. Stehmann 1078 (holotype: BHCB acc.#190958 [BHCB190958!]; isotypes: ICN, RB, to be distributed) GoogleMaps .

Diagnosis.

Nicotiana gandarela differs from all other species of the Nicotiana sect. Alatae by its short corolla tube (<15 mm), vivid red corolla limb, and unusual shaded, cave-mouth habitat.

Description.

Annual herb to 0.5 m high, not branched, pubescent with multicellular, glandular trichomes. Leaves simple, rosulate, crowded, 6-21 cm long, (1.7-) 3.5-5.0 cm wide, persistent, spatulate, slightly discolorous, the blade hirsute throughout with simple, predominantly glandular hairs, long-attenuate at the base, margin sinuous, ciliate, midribs, and secondary veins visible at both surfaces, rounded or obtuse, sometimes acute, at the apex. Inflorescence scapose, paniculate, apical or lateral, composed of monochasial cymes; bracts lanceolate, 4.3 mm long, 1.0 mm wide, viscid-hirsute; pedicels 5.8-7.7 mm long. Calyx hirsute-glandular, deeply lobed, the tube 2.5 mm long, lobes 3-5 mm long, lanceolate, unequal, the apex acute. Corolla aestivation conduplicate, with folded basal petals covering the other three; tube 1.2-1.5 cm long, 3.0-3.4 mm diam., infundibuliform, not inflated at the apex, magenta, trichomes rare, opening ca. 3.4 mm; limb zygomorphic, red, cleft into widely-depressed ovate to very widely ovate lobes, patent or slightly reflexed. Stamens 5, didynamous, adnate ca. 5 mm from the base of the corolla tube, four longer, ca. 12.5 mm long, one shorter, ca. 11.4 mm long, all filaments glabrous; anthers 0.9-1.2 mm long, white, ellipsoid, pollen whitish; nectariferous disk present. Ovary slightly conical, glabrous, style ca. 9.4 mm long, stigma bilobed, green. Capsule 2-valved, included in the calyx, 6.0-7.5 mm long, 4.4-5.5 mm in diameter, ovoid, valves with incised apex. Seeds about 0.7-0.8 mm long, 0.6-6.5 mm wide, subglobose to obovoid, testa foveolate, anticlinal walls sinuous. Chromosome number unknown.

Etymology.

The specific epithet “gandarela” is a noun in apposition and refers to Serra do Gandarela, the mountain range complex where this species is found.

Distribution and habitat.

The only known population of Nicotiana gandarela is at the Serra da Gandarela Mountain range, located in the northeast portion of the Quadrilátero Ferrífero in the Minas Gerais Brazilian State (Fig. 3A View Figure 3 ). The species occurs in a shaded site placed under a rocky outcrop ledge that extends for about 350 m along a stream and surrounded by a forest matrix, making this area a permanent humid environment. We recognized three subpopulations, each up to 150 individuals, including many seedlings (Fig. 2B View Figure 2 ). This environment resembles an open cave, and the individuals grow in bare powdery red soil originating from rock decomposition, usually with no other species co-occurring. The habitat is unique, and no similar microhabitat exists in this geologically diverse and complex area (Instituto Prístino: Atlas Digital Geoambiental: Quadrilátero Ferrífero: Geodiversidade [https://institutopristino.org.br/atlas/quadrilatero-ferrifero/]) Fig. 2A-B View Figure 2 .

Phenology.

Nicotiana gandarela has been collected with flowers and fruits in December and April.

Conservation status.

Although the single site for N. gandarela would normally suggest the species was Data Deficient (DD), the precarious nature of the region in which it grows leads us to assess it more formally. The species was preliminarily assessed as Critically Endangered - CR (B1, B2a, biii, D), mainly due to its geographic range, as the extent of occurrence (EOO) and the area of occupancy (AOO) are smaller than 100 km2 and 10 km2, respectively. The only populations of N. gandarela are located on private property and not inserted in any integral conservation unit. In addition, the Quadrilátero Ferrifero suffers from constant habitat loss ( Salles et al. 2018) as well as strong pressures from the mining sector ( Sonter et al. 2014) with concessions required to explore iron and gold (Instituto Prístino: Atlas Digital Geoambiental 2021 [https://institutopristino.org.br/atlas/quadrilatero-ferrifero/]) (Fig. 3B View Figure 3 ).

Additional specimen examined.

Brazil. Minas Gerais: Santa Bárbara. André do Mato Dentro, trilha para a cachoeira, 31 Dec 2017 (fl.,fr.), D.M.G. Oliveira, P.L.Viana & N.O.Mota 359 (BHCB).