Solanum nigrum L., Sp. Pl. 1: 186. 1753

Knapp, Sandra, Barboza, Gloria E., Bohs, Lynn & Saerkinen, Tiina, 2019, A revision of the Morelloid Clade of Solanum L. (Solanaceae) in North and Central America and the Caribbean, PhytoKeys 123, pp. 1-144 : 72-76

10. Solanum nigrum L., Sp. Pl. 1: 186. 1753 Figures 30 , 31

Solanum peregrinum E.P.Bicknell, Bull. Torrey Bot. Club 42: 332. 1915. Type. United States of America. Massachusetts: Nantucket County, Nantucket street, E.P. Bricknell 7719 (holotype: NY [NY00138955]; isotype: NY [NY00073847]).

Type.3

"Habitat in Orbis totius cultis" [sheet marked with Θ, meaning central part of Asia = Middle East], Without collector s.n. (lectotype, designated by Henderson 1974, pg. 19: LINN [LINN 248-18]).

Description.

Annual or short-lived perennial herbs to 1.0 m tall, branching 10-30 cm from the base. Stems terete to sharply angled and ridged, green, the ridges often spinescent, not markedly hollow; new growth sparsely to densely pubescent with simple, spreading, uniseriate 1-6-celled trichomes 0.5-0.6 mm long, these eglandular and/or glandular; older stems glabrescent, the trichome bases persisting as pseudospines. Sympodial units difoliate, the leaves not geminate. Leaves simple, 3.8 –7.2(– 14.5) cm long, 2.5 –5.0(– 9.5) cm wide, broadly ovate, green; adaxial surface sparsely pubescent with spreading, simple, uniseriate trichomes like those on stem evenly scattered along veins and lamina; abaxial surface more densely pubescent along veins and sparsely along lamina with eglandular and/or glandular trichomes like those of the stems; major veins 5-7 pairs; base obtuse to truncate, somewhat attenuate; margins sinuate-dentate, especially in the lower 2/3, to occasionally entire or deeply toothed; apex acute; petioles 0.5-3.0 cm long, pubescent with simple uniseriate glandular and eglandular trichomes like those of the stems. Inflorescences 0.8-2.0 cm long, lateral, internodal, unbranched (occasionally forked), with (3-)4-10 flowers spaced along the rhachis, pubescent with spreading simple uniseriate trichomes like those on stem; peduncle 0.5-1.5 cm long, straight; pedicels 3-5 mm long, 0.2-0.3 mm in diameter at the base and 0.2-0.3 mm at the apex, spreading, articulated at the base; pedicel scars spaced 0.3-0.7 mm apart. Buds subglobose, the corolla approximately halfway exserted from the calyx before anthesis. Flowers 5-merous, all perfect. Calyx tube 0.8-1.0 mm long, the lobes 0.5-0.8 mm long, 0.6-0.8 mm wide, triangular with acute or somewhat rounded apices, pubescent with spreading simple uniseriate eglandular and glandular trichomes like those of the pedicels. Corolla 10-12 mm in diameter, white with a yellow-green central portion near the base, stellate, lobed 1/2 to 2/3 of the way to the base, the lobes 4.0-5.0 mm long, 2.0-2.5 mm wide, strongly reflexed at anthesis, later spreading, densely papillate-pubescent abaxially with simple uniseriate eglandular trichomes. Stamens equal; filament tube very short to minute; free portion of the filaments 0.5-0.7 mm long, adaxially pubescent with spreading uniseriate simple trichomes; anthers 1.8-2.5 mm long, 0.8-1.0 mm wide, ellipsoid, very slightly wider at base, yellow, poricidal at the tips, the pores lengthening to slits with age and drying. Ovary globose, glabrous; style 2.5- 3.5 mm long, densely pubescent with tangled 2-3-celled simple uniseriate trichomes in the lower half where included in the anther cone, exserted 0-1 mm beyond anther cone; stigma capitate, minutely papillate, green in live plants. Fruit a globose berry, 6-10 mm in diameter, purple-black or green to yellowish green at maturity, opaque, the surface of the pericarp matte or slightly shiny; fruiting pedicels 10-12 mm long, 0.4-0.5 mm in diameter at the base, 1.0-1.1 mm in diameter at the apex, generally spreading to occasionally recurved, spaced 1.0-2.0 mm apart, dropping with mature fruits, usually not persistent but occasionally remaining on the rhachis; fruiting calyx not accrescent, tube 0.7-1.5 mm long, the lobes 1.0-2.0 mm long, spreading to reflexed in fruit. Seeds (15-)20-40 per berry, 1.8-2.0 mm long, 1.5-1.6 mm wide, flattened and tear-drop shaped with a subapical hilum, yellow, the surfaces minutely pitted, the testal cells pentagonal in outline. Stone cells absent (North America and Europe) but usually 2(-8) per berry in other areas (Asia), ca. 0.5 mm in diameter, brown. Chromosome number: 2n =6 × =72 (for vouchers and references see Särkinen et al. 2018).

Distribution.

(Figure 32 ) Solanum nigrum is native to Eurasia and has been sporadically introduced and locally naturalised in temperate North America. It is possible that populations from eastern and western areas have different origins (see below).

Ecology.

The species is found in disturbed areas between 0-2,200 m elevation in its native range, but around cities and cultivated fields from sea level to 700 m in North America.

Common names.

Canada. Black nightshade, morelle noire ( Alex et al. 1980; Bassett and Munro 1985). United States of America. Black nightshade (many sources).

Uses.

None recorded for the region (see Särkinen et al. 2018 for uses in its native range).

Preliminary conservation status ( IUCN 2017).

Least Concern (LC). See Särkinen et al. 2018.

Discussion.

Solanum nigrum is probably introduced in temperate North America; populations on the eastern seaboard best match European populations in overall morphology. Populations from the western coast (e.g., British Colombia) are morphologically more similar to Eurasian plants and it is possible that they are the result either of introductions from that region over the Pacific or are relictual native plants that came across the Bering Straits during warm periods in the Quaternary (e.g., DeChaine 2008; Ickert-Bond et al. 2009). Molecular population genetic analysis of these populations has not been done but should shed some light on the status of S. nigrum in North America.

Solanum nigrum can be distinguished from other North American species (e.g., S. americanum , S. douglasii , S. emulans , S. interius , S. nigrescens ) in the character combination of thicker peduncles and pedicels, larger seeds and fruits lacking stone cells. It has longer anthers (2.5-3 mm) than S. emulans and S. americanum , both of which have tiny anthers ca. 1.5 mm long. Like S. nigrescens , it has inflorescences with the flowers spaced along the rhachis, but S. nigrescens has prominent stone cells in the berries and smaller seeds. Solanum interius has similarly large seeds but has fewer flowers per inflorescence and distinctive basal flower pedicel position (articulation above the join with the rhachis).

Michael Nee (pers. comm.) has observed its spread and increase in the New York City area over the last decade; it is possible that more collections will be made throughout North America in the coming years.

For typification details of the many synonyms of S. nigrum see Särkinen et al. (2018).

Specimens examined.

See Suppl. materials 1 and 3.

Figures

Figure 30. Solanum nigrum L. A Habit B flower (A, B Symon 5449 [ADW 35964]). Drawing by M. L. Szent-Ivany, first published in Symon (1981), courtesy of the Board of the Botanic Gardens and State Herbarium (Adelaide, South Australia), reproduced with permission (previously also published in " PhytoKeys 106 ").

Figure 31. Solanum nigrum L. A Habit B inflorescence (dense indumentum) C inflorescence (sparse indumentum) D fully mature full-black berries, calyx lobes remaining appressed or slightly spreading (A Nijmegen acc. 824750016 B Nijmegen acc. A 34750479 C Nijmegen accession 824750029 A D Nijmegen accession A 44750150). Photos by S. Knapp (previously published in " PhytoKeys 106 ").

Figure 32. Distribution of Solanum nigrum L.