Nicotiana knightiana Goodsp., Univ. Calif. Publ. Bot. 18: 139, pls. 11, 12b (1938).

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 knightiana Goodsp., Univ. Calif. Publ. Bot. 18: 139, pls. 11, 12b (1938).

Figures 2 , 3C-D , 5A-C , 7

Type.

Peru. Dept. Arequipa, Prov. Islay, near Mollendo , 40 m, 16 November 1935 (fl, fr), Y. Mexia 04161 (holotype: UC [ UC448735 photo!]; isotypes: MO, NA, NY) .

Description.

Robust annual or short-lived shrub up to 3 m with many new stems at different stages of development arising from a lignified horizontal stem poorly anchored to the soil. Stems herbaceous, green, tomentose. Leaves ovate, undulate, base rounded to subcordate, apex obtuse to acute; bigger leaves 13 × 10 cm, indumentum similar to the stem but much denser on the abaxial side which confers a whitish colour, hairs simple, eglandular, pluricellular, brochidodromous venation, petioles a third or half as long as the leaves. Inflorescence a broad thyrse or lax panicle, 40 cm. Pedicels 0.5-1 cm in mature fruits, covered in glandular hairs. Calyx up to 7 mm, cylindric, tomentose, teethup to 2 mm, triangular. Corolla 20-23 mm excluding the limb (tubular part), tube proper 4 mm, throat 16 mm, pale yellow-green, covered in short, eglandular, hairs, limb bottom 3 mm wide, dark green, same indumentum as tube proper, notched into 5 lobes shorter than 1 mm. Stamens extending below the limb, 19 mm except one slightly shorter, filaments adnate to the tube proper, then free, pubescent in the proximal 6 mm, then glabrous and slightly curved, with stamens bending toward the stigma. Capsule 6-8 mm, ovoid. Seeds mainly subrotund, 0.5-0.7 mm, brown, surface reticulate. Embryo straight.

Distribution and habitat.

Nicotiana knightiana grows naturally in the coast of southern Perú in roadsides, pastures and rocky ravines bottoms. It was found in Chile, within the city of La Serena, Coquimbo region, in the proximity of the rivermouth of Rio Elqui, and in the proximity of Avenida Los Pescadores. It was also found growing in the city of Huasco Bajo, Atacama region (Fig. 1 ). It grows in a dense Tessaria absinthioides (Hook. & Arn.) DC. scrub, associated with Myoporum laetum G. Forst., Phyla nodiflora (L.) Greene, Schoenoplectus californicus (C.A. Mey.) Soják, Solanum pinnatum Cav., Lycium chilense Miers ex Bertero, Sarcocornia neei (Lag.) M.A. Alonso & M.B. Crespo, Distichlis spicata (L.) Greene, Thypa angustifolia L., Ambrosia chamissonis (Less.) Greene, Nicotiana glauca and Stemodia durantifolia (L.) Sw. Stemodia durantifolia var. chilensis (Benth.) C.C. Cowan. It thrives in sandy soils with water table very close to the surface.

Phenology.

Nicotiana knightiana is found flowering and fruiting between November and May.

Specimens examined.

Perú. Arequipa: Prov. Islay, Quebrada Canyon, 5-6 km north of Mollendo , 300 m, 29 September 1938 (fl, fr) C.R. Worth & J.L. Morrison 15742 ( US); 12 km southeast of Islay , 250-300 m, 28 September 1938 (fl, fr), C.R. Worth & J.L. Morrison 15724 ( US) . Chile. Atacama: Huasco bajo, 28 m, 16 October 2021 (fl), J.H. Macaya 1782 (SGO) . Coquimbo: Prov. del Elqui, La Serena, ribera sur del Rio Elqui a ca. 200 m de la desembocadura, 2 m, 23 March 2021 (fl, fr), L. Santilli 210323 (SGO); La Serena, ribera sur del Rio Elqui a ca. 200 m de la desembocadura, 1 m, 24 Nov 2018 (fl, fr), A. Ryan (iNaturalist); La Serena, avenida Los Pescadores con Canto del Agua , 3 m, 26 May 2021 (fl), B.L. Bedard (iNaturalist) .

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 2. Nicotiana knightiana (L. Santilli 210323) A habit B inflorescence C detail of lignified horizontal stem D adaxial and abaxial side of a leaf E frontal view of a flower showing limb area F lateral view of a flower. Scale bars: 1 cm.

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 5. Fruits and seeds A, C Nicotiana knightiana (L. Santilli 210323) B, D Nicotiana rupicola (N. Lavandero 1011).

Figure 7. Illustration of Nicotiana knightiana 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: 5 cm (A); 0.5 cm (B); 1 cm (C, D); 0,5 mm (E). Santilli 210323 (SGO).