Nicotiana rupicola Santilli, De Schrevel, Lavandero & Dandois, 2022

Santilli, Ludovica, Perez, Fernanda, Schrevel, Claire De, Dandois, Philippe, Mondaca, Hector & Lavandero, Nicolas, 2022, Nicotiana rupicola sp. nov. and Nicotiana knightiana (sect. Paniculatae, Solanaceae), a new endemic and a new record for the flora of Chile, PhytoKeys 188, pp. 83-103 : 83

Nicotiana rupicola Santilli, De Schrevel, Lavandero & Dandois sp. nov.

Type.

Chile. Región de Coquimbo: Prov. Elqui, Comuna de Coquimbo, Fuerte Lambert , 29°56'2.52"S, 71°20'16.46"W, 29 m, 12 November 2020 (fl, fr), N. Lavandero 1011 (holotype: SGO!; isotypes: EIF!, CONC!) .

Diagnosis.

Nicotiana rupicola is most similar to N. solanifolia , from which it differs by its congested panicle (vs. lax panicle), its short and glabrous corolla up to 18 mm (vs. corolla of 35-50 mm, pubescent), non-retroflexed corolla limb (vs. retroflexed corolla limb), mature capsule included or slightly exserted from calyx, 6-10 mm (vs. more than half the length excluded from calyx at maturity, 12-18 mm).

Description.

Perennial shrub up to 2 m with many stems arising from a lignified horizontal stem. Stems lignified, light brown, glabrous. Leaves orbicular to ovate, flat to slightly ondulate, margins slightly revolute, base rounded to cordate, apex retuse to obtuse; bigger leaves 10 × 8.5 cm, reducing their size towards the apex, densely covered in two types of hairs in both sides: simple, straight, pluricellular, up to 1 mm long, and glandular (capitate), straight, pluricellular, 50-600 µm long, brochidodromous venation, petioles a quarter to half as long as the leaves, 0.5-2.5(-5.0) cm long. Inflorescence a compact panicle, up to 35 cm; pedicels up to 0.5 cm, same indumentum as the leaves. Calyx up to 10 mm, cylindric, same indumentum as the leaves, teeth up to 3.5 mm, triangular. Corolla 17-18 mm excluding the limb (tubular part), tube proper up 5.5-6 mm, throat up to 12 mm, yellow, glabrous, limb 4 mm wide, yellow, glabrous or with scattered hairs, notched into 5 lobes. Stamens extending below the limb, similar length; filaments adnate for the first 5 mm to the tube proper, then free, pubescent at the base, then glabrous and slightly curved, with the distal portion bending toward the stigma. Capsule 6-10 mm long, ovoid. Seeds mainly angular, laterally compressed, 0.4-0.6 mm long, dark brown, surface reticulate. Embryo unknown. Chromosome number unknown. (Fig. 3 ; Fig. 4B-D ; Fig. 8 )

Distribution and habitat.

Nicotiana rupicola is endemic to Chile where it is currently known from two locations, Fuerte Lambert and Chungungo, both in the region of Coquimbo (Fig. 1 ). In Fuerte Lambert it grows among the rocks in a cliff near the ocean together with Alstroemeria magnifica Herb., Cistanthe grandiflora (Lindl.) Schltdl, Diplolepis boerhaviifolia (Hook. & Arn.) Liede & Rapini, Eulychnia breviflora Phil., Loasa elongata Hook. & Arn., Myrcianthes coquimbensis ( Barnéoud) Landrum & Grifo, Nolana acuminata (Miers) Miers ex Dunal, N. rupicola Gaudich., N. sedifolia Poepp., Ophryosporus triangularis Meyen, Plumbago caerulea Kunth, Polyachyrus poeppigii Kuntze ex Less., Puya venusta Phil., Sicyos baderoa Hook. & Arn. Sicyos baderoa var. baderoa , Solanum pinnatum Cav., Stachys pannosa Phil., In Chungungo it grows on a rocky cliff facing the ocean, together with Nolana crassulifolia Poepp. and N. sedifolia Poepp and surrounded by a scrub of Balbisia peduncularis (Lindl.) D. Don, Heliotropium stenophyllum Hook. & Arn., and Oxalis virgosa Molina.

Phenology.

Nicotiana rupicola was found flowering and fruiting in November.

Etymology.

The specific epithet derives from the Latin rupes (rock), and cola (dweller), alluding to rocky habitat of this species.

Additional specimens examined (paratypes).

Chile. Región de Coquimbo. Prov. Elqui, Comuna La Higuera, costa al Norte de Chungungo , 7 November 2006 (fl), N. García 3085 (EIF) .

Conservation status.

Nicotiana rupicola can be considered as Critically Endangered (CR) under the IUCN categories and criteria B1ab(iii); D. The criterion B1 was selected because its extent of occurrence is <100 km2 (8 km2). The criterion “a” was selected because the distribution is highly fragmented. The criterion “b(iii)” was selected because there is a projected decline in the area, extent and quality of habitat. This area is constantly threatened by the expansion of urbanization that is affecting central-north coastal Chile. One of the locations is currently found at less than 300 m from the residential area of Coquimbo and the habitat is being altered by numerous and increasing amounts of formal and informal paths and human activity (camping, garbage, etc.). Moreover, mining activities within the extent of occurrence, especially Minera Dominga, which pretends to settle between the two known localities, will more likely affect possible unknown populations and the quality of the habitat. The criterion D was selected because we observed less than 50 individuals around the two known localities.

Figures

Figure 1. Distribution map of known locations of Nicotiana knightiana (triangles) and Nicotiana rupicola (circles) in Chile. Service Layer Credits: Esri, DigitalGlobe, GeoEye, Earthstar Geographics, CNES / Airbus DS, USDA, USGS, AeroGRID, IGN, and the GIS User Community.

Figure 3. Indumentum of the leaves A, B Nicotiana rupicola with glandular hairs (N. Lavandero 1011) C, D Nicotiana knightiana with eglandular hairs (L. Santilli 210323).

Figure 4. Nicotiana rupicola (N. Lavandero 1011) A habitat B habit C inflorescence D adaxial and abaxial side of a leaf E frontal view of a flower showing limb area F detail of indumentum G lateral view of a flower. Scale bars: 1 cm.

Figure 8. Illustration of Nicotiana rupicola A entire branch B frontal view of a flower C lateral view of a flower D schematic drawing of a longitudinal section of a flower E seed. Scales: 2 cm (A); 1 cm (C, D); 0.5 mm (E). N. Lavandero 1011 (SGO, EIF, CONC).