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

Saerkinen, Tiina, Poczai, Peter, Barboza, Gloria E., Weerden, Gerard M. van der, Baden, Maria & Knapp, Sandra, 2018, A revision of the Old World Black Nightshades (Morelloid clade of Solanum L., Solanaceae), PhytoKeys 106, pp. 1-223 : 1

7. Solanum nigrum L., Sp. Pl. 1: 186. 1753 Figures 22 , 23

Solanum nigrum L. var. vulgare L., Sp. Pl. 186. 1753.

Solanum nigrum Type. "Solanum 3 α”; cultivated in George Clifford’s garden in Hartekamp, The Netherlands, Anon. s.n. (lectotype, designated here: BM [BM000558026]).

Solanum nigrum L. var. judaicum L., Sp. Pl. 186. 1753.

Solanum nigrum Type. Unknown (no specimens or illustrations cited).

Solanum vulgatum Baumg., Fl. Lips. 120. 1790, nom. illeg. superfl.

Solanum nigrum Type. Based on Solanum nigrum L. [ S. nigrum L. from Syst. Veg. ed. 14: 224. 1784 cited in synonymy]

Solanum humile Salisb., Prodr. Stirp. Chap. Allerton 134. 1796, nom. illeg. superfl.

Solanum nigrum Type. Based on Solanum nigrum L. (cited in synonymy)

Solanum judaicum Besser, Prim. Fl. Galiciae Austriac. 1: 183. 1809.

Solanum nigrum Type. No localities of specimens cited; probably from what is now Ukraine (no specimens cited; no original material located).

Solanum morella Desv., Pl. d’Angers 113. 1818, nom. illegit. superfl.

Solanum nigrum Type. Based on Solanum nigrum L. (cited in synonymy)

Solanum parviflorum Moretti ex Badarò, Giorn. Fis. Chim. Storia Nat. Med. Arti Dec. 2, 7: 364. 1824, nom. illeg, not Solanum parviflorum Nocca (1793)

Solanum nigrum Type. Italy. [Liguria]" in olivetis Liguriae occid[ose]", 1824, G.B. Badarò s.n. (no specimens cited; lectotype, designated by D’Arcy 1974a, pg. 735 [as type]: G-DC [G00144311]).

Solanum cestrifolium Jacq. ex Spreng., Syst. Veg., ed. 16 [Sprengel] 1: 680. 1825.

Solanum nigrum Type. “Patria?” [origins unknown, although probably from cultivation?] (no specimens cited; no original material found).

Solanum rhinozerothis Blume, Bijdr. Fl. Ned. Ind. 13: 695. 1826.

Solanum nigrum Type. Indonesia [no locality cited in protologue], C.L. Blume s.n. (no specimens cited; neotype, designated here: L [L2883159]).

Solanum vulgatum (L.) Spenn., Fl. Friburg. 2: 427. 1826.

Solanum nigrum Type. Based on Solanum nigrum L. var. vulgare L.

Solanum vulgatum (L.) Spenn. var. nigrum (L.) Spenn., Fl. Friburg. 2: 427. 1826.

Solanum nigrum Type. Based on Solanum nigrum L.

Solanum vulgatum (L.) Spenn. var. chlorocarpum Spenn., Fl. Friburg. 3: 1074. 1829.

Solanum nigrum Type. Switzerland. Fribourg: Sin. loc. (no specimens cited; no original material found).

Solanum moschatum C.Presl, Delic. Prag. 77. 1832.

Solanum nigrum Type. Italy. Sicily: Palermo ("in cultis ruderatis Panormi Siciliae", Anon. s.n. (no specimens cited; original material at PR?, PRC?, not found).

Solanum nigrum L. var. perennans Bertol., Fl. Ital. [Bertoloni] 2: 634. 1836.

Solanum nigrum Type. Based on Solanum moschatum C.Presl.; Solanum parviflorum Moretti ex Badarò (no specimens cited; no original material found).

Solanum nigrum L. var. atriplicifolium G.Mey., Chloris Han. 265. 1836.

Solanum nigrum Type. France. Pays de la Loire: "St. Germain de Calberte, basse Lozère”/” Mans [Le Mans]"[annotation "Solanum atriplicifolium" in Desportes hand], 1806, [illegible] s.n. (lectotype, designated here: G-DC [G00144334]).

Solanum nigrum L. var. atriplicifolium Desp. ex G.Don, Gen. Hist. 4: 412. 1838, nom. illeg. (isonym), not Solanum nigrum L. var. atriplicifolium G.Mey. (1836)

Solanum nigrum Type. Based on same original material as Solanum nigrum L. var. atriplicifolium G.Mey.

Solanum vulgare Hegetschw., Fl. Schweiz 219. Dec 1838-Jan 1839, nom. illeg. superfl.

Solanum nigrum Type. Based on " Solanum nigrum Willd." (= S. nigrum L.)

Solanum chenopodium Raf., Autik. Bot. 107. 1840.

Solanum nigrum Type. “Europa” (no specimens cited; original material probably lost).

Solanum exaratum Raf., Autik. Bot. 107. 1840.

Solanum nigrum Type. “Europa” (no specimens cited; original material probably lost).

Solanum bidentatum Raf., Autik. Bot. 108. 1840.

Solanum nigrum Type. "Italia, Sicilia" (no specimens cited; original material probably lost).

Solanum tauschii Opiz, Oekon.-techn. Fl. Böhm. [Berchtold & al.] 3: XX. 1843.

Solanum nigrum Type. Czech Republic. “Prag”, I.F. Tausch s.n. [Herb. Flor. Boehm. 1076] (no herbaria cited; no original material found, perhaps at PR?); “Luzic”, Sadel s.n. (no herbaria cited; no original material found, perhaps at PR?); "Folimanta bei Prag", Tanbler s.n. (no herbaria cited; no original material found, perhaps at PR?); Sin loc., P.M. Opiz 10/8 40 (no herbaria cited; no original material found, perhaps at PR?).

Solanum reineggeri Opiz, Oekon.-techn. Fl. Böhm. [Berchtold & al.] 3(2): XIX. 1843.

Solanum nigrum Type. Austria. Niederösterreich; Sin. loc., Reinegger s.n. (no herbaria cited; no original material found, perhaps at PR?).

Solanum decipiens Opiz, Oekon.-techn. Fl. Böhm. [Berchtold & al.] 3(2): XXIV. 1843.

Solanum nigrum Type. Czech Republic. “Troja”, P.M. Opiz 10/838; “Ruchelbad”, P.M. Opiz 23/10 835; “Radlic”, P.M. Opiz 4/8 40; “Szaslau”, Janoti 804 (no herbaria cited; no original material found, perhaps at PR?).

Solanum schultesii Opiz, Oekon.-techn. Fl. Böhm. [Berchtold & al.] 3(2): XXIV. 1843.

Solanum nigrum Type. Czech Republic. " Im Baumgarten" P.M. Opiz 10/10 35; “Prag”, P.M. Opiz s.n. (no herbaria cited; no original material found, perhaps at PR?).

Solanum nigrum L. forma stenopetalum A.Braun ex Döll, Rhein. Flor. 412. 1843.

Solanum nigrum Type. Germany. "Bei Ettlingen", A. Braun s.n. (no herbaria cited; no original material found, not found at KR); Germany. "Bei Carlsruhe in der Nähe des Linkenheimer Thores", A. Braun & J.C. Döll s.n. (no herbaria cited; no original material found, not found at KR).

Solanum nigrum L. forma chlorocarpum A.Braun ex Döll, Rhein. Flor. 413. 1843.

Solanum nigrum Type. Germany. "Bei Gerolsau und Lichtenthal unweit Baden", A. Braun & J.C. Döll s.n. (no herbaria cited; no original material found, not found at KR); Germany. "Bei Carlsruhe, Knielingen", A. Braun s.n. (no herbaria cited; no original material found, not found at KR); Germany. "Mannheim, Dossenheim, Oppenheim", J.C. Döll s.n. (no herbaria cited; no original material found, not found at KR).

Solanum guineense (L.) Lam. var. nepalense Dunal, Prodr. [A. P. de Candolle] 13(1): 49. 1852.

Solanum nigrum Type. Cultivated in Avignon Botanic Garden, from eastern Nepal, Herb. Requien s.n. (lectotype, designated here: AV [Herb. E. Requien]).

Solanum pterocaulum Dunal var. deppei Dunal, Prodr. [A. P. de Candolle] 13(1): 52. 1852, as ' Solanum pterocaulon '.

Solanum nigrum Type. Cultivated in France at Montpellier "Solanum deppei. In hortis bot. cultum" (no specimens cited, described from living plants "v.v. Hort. Monsp."; neotype, designated here: MPU [MPU310704]).

Solanum paludosum Dunal, Prodr. [A. P. de Candolle] 13(1): 57. 1852.

Solanum nigrum Type. Myanmar "cat. itir. Burm.", 1827, N. Wallich 402 (holotype: G-DC [G00144525]).

Solanum roxburghii Dunal, Prodr. [A. P. de Candolle] 13(1): 57. 1852.

Solanum nigrum Type. "In India orientali" (no specimens cited; lectotype, designated here: Wight, Icones plantarum Indiae Orientalis 2: t. 344. 1843) "Peninsula Ind. orientalis", R. Wight s.n. [herb. Wight 2326] (epitype, designated here: E [E00718973]).

Solanum memphiticum Mart. var. repandum Dunal, Prodr. [A. P. de Candolle] 13(1): 47. 1852.

Solanum nigrum Type. Germany. Saxony: cultivated in Leipzig [fide JE where original set is stored] “colui”, 1824, W. Gerhard s.n. (holotype: G [G00144263]; isotypes: JE [JE00009838], W [1889-0232903, 1889-0283857]).

Solanum nigrum L. var. atriplicifolium Desp. ex Dunal, Prodr. [A. P. de Candolle] 13(1): 50. 1852, nom. illeg., Solanum nigrum L. var. atriplicifolium G.Mey. (1836).

Solanum nigrum Type. Based on same original material (specimen) as Solanum nigrum L. var. atriplicifolium G.Mey.

Solanum cechicum Opiz, Lotos 4: 94. 1854.

Solanum nigrum Type. Czech Republic. "Um Prag", P.M. Opiz s.n. (no herbaria cited; no original material found, perhaps at PR?).

Solanum nigrum L. forma judaicum Miq., Fl. Ned. Ind. 2: 637. 1856.

Solanum nigrum Type. Indonesia. Java: [West Java] Buitenzorg [Bogor], C.L. Blume s.n. (lectotype, designated here: L [L2880952]).

Solanum nigrum L. forma paludosum (Dunal) Miq., Fl. Ned. Ind. 2: 637. 1856.

Solanum nigrum Type. Based on Solanum paludosum Dunal

Solanum hirsutum Kit. ex Kanitz, Linnaea 32: 440. 1863, nom. illeg., not Solanum hirsutum (Vahl) Dunal (1813).

Solanum nigrum Type. Slovakia. "ex itinere Arvensi ”[Árva], P. Kitaibel s.n. (lectotype, designated here: BP [Herb. Kit. fasc. IX No. 103]).

Solanum acutifolium Kit. ex Kanitz, Linnaea 32: 440. 1863, nom. illeg., not Solanum acutifolium Ruiz & Pav. (1799).

Solanum nigrum Type. Slovakia. "ex itinere Arvensi ”[Árva], P. Kitaibel s.n. (lectotype, designated here: BP [Herb. Kit. fasc. IX No. 103]).

Solanum nigrum L. var. macrocarpum Schur, Enum. Pl. Transsilv. 478. 1866.

Solanum nigrum Type. Romania. Sibiu: Sibiu "In ruderalis prope Cibinium Transilv." [protologue "Schur sert. n. 1994, auf unbebauten Orten bei Hermannstadt, Aug."], Oct, F. Schur s.n. (neotype, designated here: LW [LW00210121]; no duplicates found at BRNU).

Solanum nigrum L. var. chlorocarpum (Spenn.) Schur, Enum. Pl. Transsilv. 478. 1866.

Solanum nigrum Type. Based on Solanum vulgatum Spenn. var. chlorocarpum Spenn.

Solanum nigrum L. var. glabrum Lowe, Man. Fl. Madeira 2: 73. 1872.

Solanum nigrum Type. Portugal. Madeira: Mr. Gordon’s kitchen garden, the Mt., 8 Dec 1932, R.T. Lowe 16 [a] (lectotype, designated by Edmonds 2012, pg. 127: BM [BM000943025]).

Solanum nigrum L. var. hebecaulon Lowe, Man. Fl. Madeira 2: 73. 1872.

Solanum nigrum Type. Portugal. Madeira: ["Levada de Sta. Luzia, above Funchal, Feb", protologue], R.T. Lowe [?] s.n. (no specimens corresponding to this locality and date located).

Solanum morella Desv. subsp. nigrum (L.) Rouy, Fl. France 10: 364. 1908.

Solanum nigrum Type. Based on Solanum nigrum L.

Solanum ganchouenense H. Lév., Repert. Spec. Nov. Regni Veg. 11: 295. 1912.

Solanum nigrum Type. China. Guizhou: Gan Chouen, Aug 1910, J. Cavalérie 3815 (holotype: E [E00284474]; isotypes: E [E00284475], K [K001080605], P [P00055234]).

Solanum chenopodiifolium H. Lév., Repert. Spec. Nov. Regni Veg. 12: 531. 1913.

Solanum nigrum Type. China. Yunnan: Tong-Tchouan plaine, Sep 1912, E.E. Maire s.n. (holotype: E [E00284477]).

Solanum nigrum L. subvar. atriplicifolium (Desp. ex Dunal) Schinz & Thell., Fl. Schweiz, ed. 3, 2: 295. 1914.

Solanum nigrum Type. Based on Solanum nigrum L. var. atriplicifolium Desp. ex Dunal (= Solanum nigrum L. var. atriplicifolium G.Mey.)

Solanum peregrinum E.P.Bicknell, Bull. Torrey Bot. Club 42: 332. 1915.

Solanum nigrum Type. United States of America. Massachusetts: Nantucket County, Nantucket street, E.P. Bricknell 7719 (holotype: NY [00138955]; isotype: NY [00073847]).

Solanum probstianum Polg., Mitteil. Naturfor. Gesellsch. Solothurn 12: 30. 1938.

Solanum nigrum Type. Cultivated in Hungary at Györ, from seeds sent by R. Probst from Switzerland (Solothurn: Derendingen [Kammgarnfabrik Derendingen] in 1932), 23 Aug 1933, S. Polgár s.n. [Herb. Polg. 4051] (no specimens cited; lectotype, designated here: BP [BP-272406]).

Solanum nigrum L. var. schultesii (Opiz) Rouy, Acta Horti Gothob. 10: 201. 1935.

Solanum nigrum Type. Based on Solanum schultesii Opiz

Solanum pseudoflavum Pojark., Bot. Mater. Gerb. Inst. Komarova Akad. Nauk S.S.S.R. 17: 338. 1955.

Solanum nigrum Type. Kazakhstan. Between Vernoy Alma-Ata, Vernenskiy area, between town of Vtrnym and the station Karasukskaya, the village of Dimitrivka, V.S. Titov 2220 (holotype: LE).

Solanum nigrum L. forma pallidum Wessely, Repert. Spec. Nov. Regni Veg. 63: 311. 1960, as "Solanum nigrum subsp. nigrum var. atriplicifolium forma pallidum".

Solanum nigrum Type. Germany. Rhineland-Palatinate: Neuwied, Wirtgen s.n. (holotype: W [not seen]).

Solanum nigrum L. forma luridum Wessely, Repert. Spec. Nov. Regni Veg. 63: 311. 1960, as "Solanum nigrum subsp. schultesii forma luridum".

Solanum nigrum Type. Germany. Saxony: Dresden, Trümmerstellen am Postplatz, 22 Sep 1957, I. Wessely 0.23 (holotype: GFW).

Solanum nigrum L. subsp. schultesii (Opiz) Wessely, Feddes Repert. Spec. Nov. Regni Veg. 63: 311. 1960.

Solanum nigrum Type. Based on Solanum schultesii Opiz

Solanum nigrum L. var. incisum Täckh. & Boulos, Publ. Cairo Univ. Cairo Herb. 5: 101. 1974 [ “1972”].

Solanum nigrum Type. Egypt. Faiyum, Sinnuris, L. Boulos s.n. (holotype: CAI [CAI000175]).

Type.

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

Description.

Annual or short-lived erect to sprawling perennial herbs to 1.0 m tall, subwoody and branching at base. Stems spreading to decumbent, terete to sharply angled and ridged, green, the ridges often spinescent, older stems not appearing spinescent, not markedly hollow; new growth pubescent with simple, spreading, uniseriate, eglandular or glandular trichomes, these 1-6-celled, 0.5-0.6 mm long; 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, membranous, green, concolorous, without smell or smell somewhat foetid; 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, internodal, simple to occasionally furcate, the flowers spaced along the rhachis, with (3-)4-10 flowers, 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, conical, 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, the pericarp dull or slightly shiny; fruiting pedicels 10-12 mm long, 0.4-0.5 mm in diameter at the base and 1.0-1.1 mm at apex, generally spreading to occasionally recurved, spaced 1.0-2.0 mm apart, dropping with mature fruits, not persistent but occasionally remaining on the inflorescence; fruiting calyx not accrescent, the tube ca. 1 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 =6x=72 ( Jørgensen 1928; Tokunaga 1933; Ellison 1936; Nakamura 1937; Stebbins and Paddock 1949; Baylis 1958; Heiser et al. 1965; Saarisalo-Taubert 1967; Venkateswarlu and Rao 1972 [as S. nigrum S8, S11, S19]; Henderson 1974; Tandon 1974; Randell and Symon 1976; Edmonds 1977, 1981, 1982, 1983, 1984a; Ganapathi and Rao 1986a; Symon 1981; Bukenya 1996).

Distribution

(Figure 24 ). Widespread species native to Eurasia (western Europe to Japan), northern Africa and Australia, sporadically introduced in South Africa and naturalised locally in temperate North America.

Ecology.

Weed of cultivated land, open spaces in forests and roadsides; found in disturbed areas between 0-2,200 (3,500) m elevation.

Common names.

Australia: blackberry, black berry nightshade ( Symon 1981); China: paak fa tsai ts’o [Hainan], long kui ( Zhang et al. 1994); Denmark: kirtel-natskygge, sort natskygge ( Hartvig 2015), sort natskygge ( Frederiksen et al. 2006); Egypt: anabadib [Berber], aneb el dib, enab athib; Estonia: must maavits ( Kukk and Kull 2005; Finland: mustakoiso, karvamustakoiso ( Hämet-Ahti et al. 1998); France: morelle noire ( Jauzein and Nawrot 2011); Germany: schwarzer Nachtschatten; India: makoi [Hindi], kakamachi [Bengali, Sanskrit], kakahva [Sanskrit]; Iraq: dubbais, habbat seda; Italy: Solanum morella commune, erba Solanum morella , pomidorella, ballerina ( Pignatti 1982), solano nero; Japan: inuhozuki, inn-hodzuki, kanzashi-inuhoozuki; Libya: aneb el dib/aneb el dhib; Lithuania: juodoji kiauliauogė ( Natkevičaitė-Ivanauskienė 1976); Malaysia: beliwan; Nepal: kamai; New Zealand: black nightshade ( Webb et al. 1988); Norway: svartsøtvier ( Lid et al. 2005); Pakistan: tolangur; Philippines: amti, amtih (Ifugao language), moti; Poland: psianka czarna ( Pawłowskiego 1963); Portugal: herva moira morelle commune, pera de Santa Maria; Saint Helena: Tristan blackberry; Slovenia: lulok čierny ( Bertová and Goliašová 1993); Spain: yerba mora, hierba mora; Sweden: nattskatta, hårig nattskatta ( Mossberg et al. 2003); United Kingdom: black nightshade

Uses.

Leaves used as vegetable in India, China, southeast Asia and in Europe (in local areas); thought to be poisonous by association with the deadly nightshade, Atropa belladonna (see Uses in introductory section). Berries sometimes used for jam ( Viljoen 2011).

Preliminary conservation status

( IUCN 2016). Solanum nigrum is a widely distributed amphitropical species across temperate and subtropical areas in the Old World; it can be assigned a status of LC (Least Concern; Table 7 ).

Discussion.

Solanum nigrum , the type species of the genus Solanum , is a widespread weed with much morphological variation recognised at various infraspecific levels by many different authors (e.g. Linnaeus 1753; Opiz 1843). There are almost 100 names associated with the taxon and the status of some of these remains uncertain due to difficulty in finding types but we include them here based on their descriptions (but see Doubtful species). Here, we adopt an inclusive and broad concept of the species and recognise all infraspecific taxa under a single, more widespread and morphologically variable species. Two of the most commonly recognised infraspecific units include S. nigrum subsp. schultesii (Opiz) Wessely (villous, with glandular hairs) and S. nigrum subsp. nigrum (eglandular). Previous studies have found no support for the recognition of these or any other infraspecific taxa within S. nigrum based on morphological ( Henderson 1974), seed protein ( Edmonds and Glidewell 1977) or molecular marker data ( Dehmer 2001; Dehmer and Hammer 2004; Olet 2004; Manoko 2007).

We do not include material identified as S. nigrum in recent African regional floras ( Edmonds 2006a, 2006b, 2012) in our circumscription of this species. We follow Olet (2004) and Olet et al. (2011) and consider this material to represent the wild form of S. scabrum. In Africa, we consider only material from northern Africa around the Mediterranean and a few specimens (probably introduced from Europe) from South Africa to be true S. nigrum . Both S. nigrum and S. scabrum are hexaploids and morphologically similar, but can be distinguished on the following suite of morphological characteristics; Solanum nigrum has leaves with rather indistinct petioles, inflorescences with the flowers spaced along the rhachis, acute calyx lobes that are more or less appressed to the berry in fruit, and berries that not markedly shiny and often have stone cells (particularly in Asia). Solanum scabrum has distinctly petiolate leaves, the flowers are usually tightly congested at the tips of inflorescences or inflorescence branches, the calyx lobes are rounded, irregular and strongly reflexed in fruit and the berries are shiny with thick pericarp and lack stone cells. In addition, the fruiting pedicels of S. nigrum are spreading to somewhat recurved, while those of S. scabrum are erect and strongly spreading.

Throughout its range in Europe and into Eurasia as far as western China, S. nigrum is sympatric with S. villosum . The simplest distinguishing character is mature berry colour; S. villosum has red, orange or yellow berries, while those of S. nigrum are black or green. Many old collections, however, do not state berry colour on the label, so identification can be difficult. Calyx lobes are useful for distinguishing these taxa; S. nigrum calyx lobes are usually deltate and acute, with sharp triangular sinuses, while those of S. villosum are longer, usually rounded at the tip and the sinuses are broad and quite transparent (see description of S. villosum ), leaving a paler “window” just below the sinus in flower buds and early flowers. The shiny, translucent berries of S. villosum (mostly slightly ellipsoid) usually dry blackish-brown, but are distinct from the matte, more opaque berries of S. Solanum nigrum . Neither species has stone cells in Europe, but in Asia, S. nigrum usually has 2 (or occasionally more) stone cells in the berries. Both species retain pedicels after fruits drop, but S. nigrum is not as extreme in this regard and often plants are found with old inflorescences with no remaining pedicels.

Solanum nigrum has been considered native only to Europe, but our study of populations of this widespread weed across its range has shown that the largest morphological variation can be observed in Asia. Populations of S. nigrum from Asia have more stone cells in the fruit and the plants have a more delicate look overall with longer peduncles and often fewer flowers per inflorescence. Material from Asia has been described as different taxa (e.g. S. guanchounense , S. chenopodiifolium ) but the variation is continuous across the range, with European populations being more invariant (except in leaf shape and indumentum). Populations in Europe represent a relatively monomorphic set of populations compared to material from China and eastern Asia. We therefore consider that the species is native to the entire Eurasian area, with limited introductions to North America. North American material we have seen appears most similar to European plants based on morphology, suggesting the introduction to North America came from European populations, but this has not been tested genetically.

Australian populations of S. nigrum could have originated either from Europe or from Asia. In general, S. nigrum in Australia does not seem to have stone cells in general and plants fall into two continuously variable groups: one is similar to classic European S. nigrum and the other is more similar to plants from eastern and south-eastern Asia.

Solanum nigrum is an autoalloploid species, now thought to have originated from a tetraploid S. villosum and a diploid S. americanum by spontaneous amphiploidy ( Edmonds 1979a; Ganapathi and Rao 1986b, 1986c; Poczai and Hyvönen 2011). Cytogenetic and crossing studies show high fertility and regular pairing of bivalents at meiosis in crosses of S. villosum , S. retroflexum and S. americanum with S. nigrum ( Edmonds 1979a; Ganapathi and Rao 1986b, 1986c, 1986d). Of the two tetraploid species, S. villosum and S. nigrum are sympatric at least across parts of their native ranges which would make it more likely that S. nigrum is an autoalloploid derived from the autopolyploid S. villosum and the diploid S. americanum . Molecular analyses have now shown that the two hexaploids S. nigrum and S. scabrum share a parental species with the tetraploid S. villosum ( Poczai and Hyvönen 2011). Artificially produced hexaploids from tetraploid crosses of S. villosum and S. americanum have been shown to be fertile and represent the glandular variant of S. nigrum (sometimes recognised as subsp. Solanum nigrum schultesii (Opiz) Wessely; Edmonds 1979a). It is hence becoming more clear that the tetraploid parent of S. nigrum is S. villosum and not S. retroflexum . Artificial hexaploids have been produced using S. villosum and S. americanum by several authors and the artificial hexaploids resemble S. nigrum morphologically ( Tandon and Rao 1964; Venkateswarlu and Rao 1969, 1972; Soria and Heiser 1959; Edmonds 1979a). Reciprocal backcrossing of the artificial hexaploids with S. nigrum results in a high fruit set ( Venkateswarlu and Rao 1969, 1972; Edmonds 1979a), supporting the hypothesis that S. villosum and S. americanum are the parent species of S. nigrum . The autoallopolyploid origin of S. nigrum has been suggested by previous authors ( Magoon et al. 1962; Rao 1971). In the light of the current molecular evidence combined with the accumulating evidence from cytological and crossing studies, the alternative hypotheses on the origin of S. nigrum as an autohexaploid ( Jørgensen 1928; Nakamura 1935, 1937) and an allopolyploid derived from three distinct genomes (e.g. Tandon and Rao 1964, 1966a; Henderson 1974; Edmonds 1979a) are becoming less likely.

In parts of eastern England, S. x procurrens A.C.Leslie ( Leslie 1978), a sterile tetraploid hybrid between S. nitidibaccatum and S. nigrum , is locally established where the two species grown together ( Stace 2010: 531; Stace et al. 2015). The hybrid has also been recorded in New Zealand ( Webb et al. 1988). These plants are intermediate between the two species, with glandular pubescence and black berries with somewhat accrescent calyx lobes. A good description and distribution map for this local hybrid can be found in Stace et al. (2015). We have not seen convincing material from elsewhere in Europe of this hybrid, but it potentially occurs wherever S. nitidibaccatum and S. nigrum co-occur. As it is sterile, however, it does not spread or persist.

Linnaeus (1753) recognised six varieties of his S. nigrum , of which four are now considered distinct species (var. Solanum nigrum patulum = S. americanum ; var. Solanum nigrum villosum = S. villosum ; var. Solanum villosum guineense = S. scabrum ; var. Solanum scabrum virginicum = S. emulans Raf.). Henderson (1974) lectotypified S. nigrum with the single sheet in the Linnean herbarium (LINN 248.28) corresponding to this species. In the protologue, Linnaeus (1753) cited several other elements and it is from these that we select the lectotype for var. Solanum nigrum vulgare while, for var. Solanum nigrum Solanum nigrum judiacum , he cites no elements. It is possible that a specimen from his herbarium was the basis for this infraspecific epithet and that the sheet in LINN is that referred to by this name.

In describing S. judaicum , von Besser (1809) did not specifically cite Linnaeus’s varietal name, so we have assumed he was coining a new name, rather than making a combination.

The name S. cestrifolium has a complex history; we can find no place of publication for "Solanum cestrifolium Jacq." as cited by Sprengel (1825) and Weinmann (1824:100; in synonymy with his nomen nudum S. besserianum , see Doubtful names under S. besseri Weinm. ex Roem. & Schult.). The name S. cestrifolium has also been attributed to Willdenow by Gussone (1825, as a nomen nudum) and subsequently validated by Colla (1835); this epithet refers to plants now considered part of the species S. bahamense L. ( Strickland-Constable et al. 2008). We have not lectotypified S. cestrifolium Jacq. ex Spreng. in the hope that material amongst the cultivated holdings at W will reveal potential original material.

Blume (1826) cited no specimens for any of the names in his Bijdragen tot de flora van Nederlandsch Indië nor do many of the descriptions have specific localities. We have found a specimen labelled S. rhinozerothis in Blume’s hand in L (L.2883159) that we here select as the neotype for that species, but have not found any material directly attributable to Blume that we could associate with S. uliginosum (see under Doubtful names).

The varietal epithet " Solanum atriplicifolium " was used by many authors to refer to plants of S. nigrum with dentate leaf margins. It appears to have been used in reference to a specimen that was annotated "Solanum atriplicifolium" by Narcisse Desportes, probably seen in Paris or Geneva. Georg Meyer of Hannover (1818) was the first botanist to effectively and validly publish this epithet and did so at the varietal rank. Dunal (1852) cited the same material and said that the collector was “Prost”, though the G herbarium catalogue states the collector as Desportes. We select this G-DC (G00144334) sheet as the lectotype for S. nigrum var. atriplicifolium because it appears to be original material by way of locality and annotation. The combinations made by Don (1837) and Dunal (1852) are isonyms and therefore have no standing, but we include them here because they have been widely used and cited and other combinations have been made based upon them.

The various names coined by the amateur Czech botanist Philipp Maximilian Opiz and here recognised as synonyms of S. nigrum were all included by him in the “superspecies” S. nigrum and, from descriptions and key, represent leaf shape, pubescence and inflorescence size variations of that species. Opiz’s enormous herbarium is housed mostly in PR ( Kirschner et al. 2007) with duplicates in PRC and other major European herbaria. We have been unable to visit Prague to examine the no doubt extensive gatherings of S. nigrum and have found few unambiguous duplicates of the collections cited in the protologues. We therefore leave the typification of these infraspecific names until further study of Opiz’s herbarium can be undertaken. The same is true for the infraspecific names coined by Johann Döll (1843), whose protologues cited some presumed collections, but no herbaria. Searches at KR reveal no original material and the A. Braun collections cited were probably at B and were destroyed. Again, these infraspecies refer to the highly variable populations of S. nigrum in central Europe. Döll (1843) attributed the infraspecific epithets var. Solanum nigrum chlorocarpum and Solanum stenopetalum to Braun; he was thus coining a new name “chlorocarpum” and not citing Spenner’s earlier use of this epithet.

Solanum chenopodium , S. exarmatum and S. bidentatum were all coined by Rafinesque (1840) for European plants. He cited "S. nigrum var. undatum", a name never published, in the protologue of S. chenopodium and suggested that S. bidentatum was the same as " S. patulum of India". We here place these three in the synonymy of S. nigrum based on their rather meagre descriptions; Rafinesque’s herbarium was destroyed, but occasionally fragments he sent to European herbaria survive (e.g. material relating to S. emulans Raf.)

Dunal (1852) described several varieties of his complex taxon S. pterocaulum (in 1852 written as Solanum pterocaulon ); most of these correspond to S. scabrum . His var. Solanum pterocaulum deppei was described from living material "v.v. Hort. Monsp."; a sheet in MPU (MPU310704) labelled "Solanum deppei. In hortis bot. cultum" is here selected as neotype for this name.

A single collection of a plant from Nepal cultivated in Avignon was cited in the protologue of S. guineense var. nepalense ( Dunal 1852), housed in "h. Requien". A sheet at AV clearly labelled as "S. guineense β nepalense Prodr." is most likely original material for the name and we designate this as the lectotype.

Solanum roxburghii was coined by Dunal (1852) as a replacement for "S. rubrum" as used by Roxburgh (1824) in his Flora Indica. Dunal cited the publications of Roxburgh (1824, but with the incorrect page number of 216 rather than 246) and Nees van Esenbeck (1837) and an illustration by Wight, but cited no herbarium material. We consider the illustration in Wight (1843) as the only unambiguous original material for this name and designate it as the lectotype for S. roxburghii . Both the citations of "Solanum rubrum" are based on the epithet of Miller and/or Linnaeus and are not at all clear. Differentiating S. nigrum from S. villosum (both which occur in India) can be difficult without ripe berries and, since berry colour in the original hand-coloured illustration at E is green, we are certain the Wight illustration depicts a plant of S. nigrum , with flowers spaced along the inflorescence and sepals that are not reflexed in fruit. We therefore designate an epitype from amongst the sheets collected by Wight (E00718973) to fix the application of this name. Early authors, such as Roxburgh and Nees van Esenbeck, included both red/orange and black-fruited plants in their circumscriptions of both S. nigrum and S. rubrum . The sheets in the East India Company herbarium at K (see de Candolle and Radcliffe-Smith 1981; Noltie 2005) are a complex and confusing mixture of S. americanum and S. villosum ; none of these specimens matches the illustration as well as does the E sheet we select here as the epitype. This again illustrates the difficulty that early authors had with these very similar plants and the dangers of assuming that collections are duplicates.

Miquel (1857) recognised several forms of S. nigrum in his broad species circumscription. His forma Solanum nigrum judiacum was specifically coined to encompass S. judaicum Besser in the sense of Blume (1826), but excluding Besser’s material. We therefore consider this the coining of a new name and not a new combination based on Besser’s S. judaicum ; the lectotype selected is a sheet in L (L2880952) with the locality "in uliginosis circa Buitenzorg" as cited by Blume and in Blume’s hand.

The names coined by the Hungarian botanist Pál Kitaibel were published posthumously by Kanitz (1863) and are largely illegitimate (some were used in earlier publications by Schultes, see discussion under S. villosum ). Solanum hirsutum and S. acutifolium were published as alternative names "Solanum hirsutum vel acutifolium" and therefore have the same type; we have selected the sheet in the Kitaibel herbarium at BP with the locality matching that in the protologue ("ex itinere Arvensi", BP [Herb. Kit. fasc. IX: 103]).

We have selected a specimen collected by Schur (LW00210121), but with a different date of collection and exact locality, as the neotype for S. nigrum var. macrocarpum ; searches in the other relevant herbaria revealed no original material.

Edmonds (2012) only lectotypified one of the varieties of S. nigrum from Lowe’s Manual Flora of Madeira (1872). Lowe’s var. Solanum nigrum hebecaulon cited a single locality and date "Levada de Sta. Luzia, above Funchal, Feb"; no specimens corresponding exactly to that are found in BM or at K.

Solanum probstianum was described from material cultivated in Hungary from seeds sent by Rudolf Probst to Sandor Polgár in 1932. Although no specific specimens were cited in Polgár’s protologue (in Probst 1938), there are many specimens annotated "Solanum probstianum" in Polgar’s hand at BP that are clearly cultivated and appear to be from this original seed collection. We have selected one of these with both flowers and fruits as the lectotype of S. probstianum [BP-272406], it bears a collecting number (4051) and was collected in July 1933. We do not consider the other sheets with this number as necessarily duplicates; the sheets do not have consistent collection numbers and may represent individual plants from the cultivated population collected on different dates in the same or different years.

Selected specimens examined.

A total of 1,537 specimens were examined from 82 countries during the study across Africa, Asia, Australia, Eurasia and the Pacific. Adventive specimens from the New World were also studied in order to understand the full range of morphology within the species. All specimens examined can be seen in Appendix 2 (csv format) and Appendix 3 (traditional Specimens Examined list in pdf format).

Figures

Figure 22. 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.

Figure 23. 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 acc. 824750029 A, D Nijmegen acc. A 44750150). Photos by S. Knapp.

Figure 24. Distribution of Solanum nigrum L in the Old World.