Solanum chenopodioides Lam., Tabl. Encycl. 2: 18. 1794

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 : 37-41

2. Solanum chenopodioides Lam., Tabl. Encycl. 2: 18. 1794 Figures 6 , 7

Solanum sublobatum Willd. ex Roem. & Schult., Syst. Veg., ed. 15 bis [Roemer & Schultes] 4: 664. 1819. Type. Argentina. Buenos Aires, Anon. s.n. [probably P. Commerson] (Herb. Willdenow 4336) (lectotype, designated by Edmonds 1972, pg. 105 [as type ex photo]: B [B-W04336-01-0]).

Solanum besseri Weinm., Syst. Veg., ed. 15 bis [Roemer & Schultes] 4: 593. 1819. Type. "In America" [cultivated in Europe?], Anon. s.n. (no specimens cited; no original material located; neotype, designated by Särkinen et al. 2018, pg. 65: G-DC [G00144198]).

Solanum subspatulatum Sendtn., Fl. Bras. (Martius) 10: 45, tab. 4, fig. 16-18. 1846. Type. Brazil. Sin. loc., F. Sellow s.n. (holotype: B, destroyed, F neg. 3183; lectotype, designated by D’Arcy 1974a, pg. 735 [as type]: P [P00384051]; isolectotype: F [v0361921F, acc. # 621700, fragment]).

Witheringia chenopodioides (Lam.) J. Rémy, Fl. Chil. [Gay] 5: 69. 1849. Type. Based on Solanum chenopodioides Lam.

Solanum isabellei Dunal, Prodr. [A. P. de Candolle] 13(1): 153. 1852. Type. Uruguay. Montevideo, Lat. aust. 34°45'08", 1838, A. Isabelle s.n. (lectotype, designated by Särkinen et al. 2018, pg. 65: G-DC (G00145645); isolectotypes: F [v0073298F, acc. # 680251; v0073299F, acc. # 680253], K [K000585686], P [P00384071], W [acc. # 1889-115034]).

Solanum chenopodiifolium Dunal, Prodr. [A. P. de Candolle] 13(1): 44. 1852. Type. Argentina/Uruguay. "Buenos Aires et Montevideo", P. Commerson s.n. (lectotype, designated Edmonds 1972, pg. 108 [as holotype], second step designated by Särkinen et al. 2018, pg. 65: P [P00384081]).

Solanum crenatodentatum Dunal var. ramosissimum Dunal, Prodr. [A. P. de Candolle] 13(1): 54. 1852. Type. United States of America. Louisiana: "Basse Louisiane", 1839, G.D. Barbe 82 (holotype: P [P00362535]).

Solanum gracile Dunal, Prodr. [A.P. de Candolle] 13(1): 54. 1852, nom. illeg., not Solanum gracile Sendtn. (1846). Type. Brazil. Rio de Janeiro: "Rio de Janeiro", 1831-1833, C. Gaudichaud 520 (lectotype, designated by Henderson 1974, pg. 46: G-DC [G00144391]; isolectotypes: G [G00343457], P [P00384052, P00384053]).

Solanum gracile Dunal var. microphyllum Dunal, Prodr. [A. P. de Candolle] 13(1): 54. 1852. Type. Argentina/Uruguay. "Circa Buenos Ayres et Montevideo", P. Commerson s.n. (lectotype, designated by Morton 1976, pg. 151: P [P00384061, Morton neg. 8207]; possible isolectotype: F [v0073283F, acc. # 976485, fragment only]).

Solanum nodiflorum Jacq. var. microphyllum Hassl., Repert. Spec. Nov. Regni Veg. 9: 118. 1911. Type. Paraguay. Estrella: Mar, É. Hassler 10271 (holotype: G?, Morton neg. 8612).

Solanum vile Bitter, Repert. Spec. Nov. Regni Veg. 11: 221. 1912. Type. Brazil. Rio de Janeiro: Restinga do Harpoador, E. Ule 4310 (lectotype, designated by Särkinen et al. 2018, pg. 66: CORD [CORD00004277]; isolectotype: HBG [HBG-511507]).

Solanum gracilius Herter, Rev. Sudamer. Bot. 7: 266. 1943. Type. Based on (replacement name for) S. gracile Dunal

Solanum ottonis Hyl., Uppsala Univ. Årsskr. 7: 279. 1945. Type. Based on (replacement name for) Solanum gracile Dunal

Type.2

Mauritius. "Ex ins. Mauritiana", Herb. Lamarck s.n. (lectotype, designated by Barboza et al. 2013, pg. 242: P [P00357629]).

Description.

Annual herbs to short-lived perennial shrubs up to 1.0 m tall, subwoody and branching at base. Stems terete, green-grey to straw colour, sprawling, somewhat weak and decumbent, not markedly hollow; new growth pubescent with simple, uniseriate appressed 1-6-celled eglandular trichomes, these 0.1-0.6 mm long; older stems more sparsely pubescent, glabrescent. Sympodial units difoliate, the leaves not geminate. Leaves simple, 1.5 –5.5(– 7.0) cm long, 0.5 –3.0(– 3.5) cm wide, lanceolate to narrowly ovate, rarely ovate, discolorous; adaxial surface green, sparsely pubescent with appressed 1-4-celled translucent, simple, uniseriate trichomes like those on stem, these denser along the veins; abaxial surface pale grey, more densely pubescent with trichomes like those of the upper surface evenly distributed across lamina and veins; major veins 3-6 pairs, not clearly evident abaxially; base attenuate, decurrent on the petiole; margins entire or sinuate; apex acute to obtuse; petioles (0.5-)1.0 –1.5(– 3.5) cm long, sparsely pubescent with simple uniseriate trichomes like those of the stems and leaves. Inflorescences 1.0 –2.5(– 4.0) cm long, lateral, generally internodal but appearing leaf-opposed on young shoots, unbranched or rarely forked, with 3 –7(– 10) flowers clustered near the tips (sub-umbelliform), sparsely pubescent with appressed 1-2-celled simple uniseriate trichomes; peduncle 1.0 –2.3(– 4.0) cm long, strongly deflexed downwards in fruit; pedicels 5-10 mm long, ca. 0.5 mm in diameter at the base and 1 mm in diameter at the apex, straight and spreading, articulated at the base; pedicel scars spaced ca. 0-1 mm apart. Buds elongate-oblong, the corolla only slightly exserted from the calyx tube before anthesis. Flowers 5-merous, all perfect. Calyx tube 2-3 mm long, conical, the lobes 0.6-1.2 mm long, less than 1 mm wide, broadly deltate to triangular with acute to obtuse apices, sparsely pubescent with 1-4-celled appressed hairs like those on stem but shorter. Corolla 6-12 mm in diameter, white with a black and yellow-green central portion near the base, the black colour usually distal to the yellow green, deeply stellate, lobed 4/5 of the way to the base, the lobes 3.5-4.0 mm long, 1.5-1.9 mm wide, strongly reflexed at anthesis, later spreading, densely puberulent-papillate abaxially with 1-4-celled simple uniseriate trichomes, these denser on the tips and margins. Stamens equal; filament tube minute; free portion of the filaments 0.6-1.0 mm long, adaxially pubescent with simple tangled uniseriate 4-6-celled simple trichomes; anthers (2.0 –)2.3– 2.8 mm long, 0.5-0.8 mm wide, narrowly ellipsoid, yellow, poricidal at the tips, the pores lengthening to slits with age and drying, the connective becoming darker brown with age in dry plants. Ovary globose, glabrous; style 3.7-4.5 mm long, densely pubescent with 2-3-celled simple uniseriate trichomes in the lower half where included in the anther cone, exserted up to 1.5 mm beyond the anther cone; stigma capitate, minutely papillate, green in live plants. Fruit a globose berry, 4-9 mm in diameter, dull purplish-black at maturity, opaque, the surface of the pericarp matte and somewhat glaucous; fruiting pedicels 6-13 mm long, 1.2-1.4 mm in diameter at the base, reflexed and slightly curving, dropping with mature fruits, not persistent; fruiting calyx not accrescent, the tube less than 1 mm long, the lobes 1-1.5 mm long, appressed against the berry. Seeds (13 –)20–35(– 50) per berry, 1.2-1.4 mm long, 1.0-1.2 mm wide, flattened and tear-drop shaped with a subapical hilum, pale yellow, the surfaces minutely pitted, the testal cells pentagonal in outline. Stone cells absent. Chromosome number: 2n =2 × =24 (see Särkinen et al. 2018).

Distribution.

(Figure 8 ) Solanum chenopodioides is native to southern South America, and has been introduced globally, largely with the wool trade. The species is relatively uncommon in North America, where it is most likely introduced.

Ecology.

Solanum chenopodioides is an adventive species in North America and occurs only in sporadic populations close to urban areas and human disturbance between 0 and 2,000 m elevation.

Common names.

None recorded.

Uses.

None recorded.

Preliminary conservation status ( IUCN 2017).

LC (Least Concern). Solanum chenopodioides is a widespread weed of disturbed areas (see Barboza et al. 2013; Särkinen et al. 2018). For EOO see Table 6 .

Discussion.

Solanum chenopodioides is a weedy, ruderal species occurring mainly in coastal parts of North America. The species has distinct grey-green appearance due to the pubescence of appressed, eglandular white trichomes. It is morphologically similar to S. pseudogracile and some populations of S. americanum around the coast of the Gulf of Mexico. Solanum chenopodioides can be distinguished from S. pseudogracile only with difficulty, but the short-triangular calyx lobes with acute apices that remain appressed to the berry at fruit maturity, as opposed to the longer, rectangular calyx lobes with rounded to acute apices that are reflexed in fruit of S. pseudogracile , are characters that distinguish the taxa. In flower, the extension of style beyond the anther cone is a good character to separate S. chenopodioides from S. pseudogracile ; the style remains almost completely inside the anther cone in S. chenopodioides (exserted to 1-1.5 mm) and is clearly exserted in S. pseudogracile (exserted to (1)2.0-2.5 mm). Many specimens annotated as S. chenopodioides from around the Gulf of Mexico (e.g., Florida) are actually plants of S. pseudogracile .

Solanum chenopodioides can be distinguished from S. nigrescens by the lack of stone cells in fruit, while S. nigrescens has always 4-13 stone cells per fruit. Anthers in S. chenopodioides are always much longer (2.0-2.8 mm) than in S. americanum (0.8-1.5 mm). The strongly deflexed peduncle and pedicels in fruit are distinctive in S. chenopodioides but are not always obvious in herbarium specimens.

Typification details for the synonyms of S. chenopodioides can be found in Särkinen et al. (2018).

Specimens examined.

See Suppl. materials 1 and 3.

Figures

Figure 6. Solanum chenopodioides Lam. A Habit B detail of adaxial leaf surface C detail of abaxial leaf surface D opening bud E dissected flower F fruiting branch G detail of infructescence H maturing fruit I fully mature fruit (A-E Fox s. n. F-I Hieronymus s. n.). Drawing by R. Wise (previously published in " PhytoKeys 106 ").

Figure 7. Solanum chenopodioides Lam. A Habit B buds C flowers at full anthesis D fully mature matte black fruits with appressed calyx lobes (A-D Nijmegen accession A 14750051). Photos by S. Knapp and G. van der Weerden (previously published in " PhytoKeys 106 ").

Figure 8. Distribution of Solanum chenopodioides Lam.