Solanum nigrum |
Solanum americanum |
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black nightshade, European black nightshade |
American black nightshade, American black or common or West Indian nightshade, glossy nightshade, little white nightshade, small-flower nightshade, white nightshade |
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Habit | Herbs, annual or perennial, erect or sprawling, unarmed, to 1 m, glabrescent to moderately pubescent, hairs unbranched, to 1 mm, usually eglandular or occasionally glandular. | Herbs to subshrubs, annual to perennial, erect, unarmed, to 1.5 m, glabrate to moderately pubescent, hairs whitish, unbranched, to 1 mm, eglandular. |
Leaves | petiolate; petiole 0.5–3 cm; blade simple, ovate, 3.5–7 × 2.2–5 cm, margins entire to coarsely toothed with 3–5 lobes per side, base truncate to cuneate. |
petiolate; petiole 1–4 cm; blade simple, ovate to ovate-elliptic, 2–10.5 × 1–4.5 cm, margins entire or shallowly sinuate-dentate, base decurrent. |
Inflorescences | extra-axillary, unbranched or occasionally forked, racemelike, (3–)4–10-flowered, 1–2 cm. |
extra-axillary or leaf-opposed, unbranched, usually umbel-like, 3–10-flowered, 0.5–3 cm. |
Pedicels | 0.5–1 cm, spreading to occasionally recurved in flower and fruit. |
erect or spreading, 0.3–1 cm in flower, to 1.5 cm in fruit. |
Flowers | radially symmetric; calyx not accrescent, unarmed, 1.5–2 mm, sparsely pubescent, lobes deltate, spreading to reflexed in fruit; corolla white with yellowish central star, stellate, 1–1.5 cm diam., without interpetalar tissue; stamens equal; anthers ellipsoidal, (1.8–)2–2.5 mm, dehiscent by terminal pores that open into longitudinal slits; ovary glabrous. |
radially symmetric; calyx somewhat accrescent, unarmed, 1–3 mm, lobes deltate, strongly reflexed in fruit; corolla white, sometimes with yellowish central star, stellate, 0.4–0.8 cm diam., without interpetalar tissue; stamens equal; anthers ellipsoidal, 0.7–1.5 mm, dehiscent by terminal pores that open into longitudinal slits; ovary glabrous. |
Berries | dull or slightly shiny purple-black or green to yellowish green, globose, 0.5–1 cm diam., glabrous, without sclerotic granules. |
shiny purplish black, globose, 0.5–1 cm diam., glabrous, with (0–)2–4(–6) sclerotic granules, usually 2–4 larger and 2 smaller. |
Seeds | yellow, flattened, 1.8–2 × 1.5–1.6 mm, minutely pitted. |
pale yellow to brown, 1–1.5 × 0.5–1.5 mm, minutely pitted. |
2n | = 72. |
= 24. |
Solanum nigrum |
Solanum americanum |
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Phenology | Flowering May–Oct. | Flowering May–Nov (year-round in Fla.). |
Habitat | Disturbed areas, irrigated fields. | Weedy habitats, secondary forest, disturbed areas. |
Elevation | 0–2200 m. (0–7200 ft.) | 0–1000(–2000) m. (0–3300(–6600) ft.) |
Distribution |
AK; CA; DC; FL; GA; IA; ID; MA; MD; ME; MO; MT; NC; NJ; NV; NY; OK; OR; PA; TX; UT; VA; WA; BC; NS; ON; Eurasia; n Africa [Introduced in North America; introduced also in Pacific Islands (New Zealand), Australia]
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AL; AZ; CA; FL; GA; LA; MO; MS; OR; SC; TX; UT; WA; BC; Mexico; Central America; South America; West Indies [Introduced in Europe, Asia, Africa, Pacific Islands, Australia]
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Discussion | Many regional floras have used Solanum nigrum as the name for various species in the black nightshade group, and it can be difficult to distinguish this species from S. emulans and S. nigrescens. Solanum nigrum can be distinguished from the native North American species of the black nightshade group (S. americanum, S. douglasii, S. emulans, S. interius, S. nigrescens) by its thicker peduncles and pedicels, larger seeds, and fruits lacking sclerotic granules. Solanum nigrum was probably introduced from northern Europe and has been locally naturalized in North America. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Solanum americanum is a morphologically variable and globally distributed weedy species. It has often been confused with other species in the black nightshade group such as S. emulans, S. nigrescens, S. nigrum, and S. pseudogracile and has often been referred to as S. nodiflorum in floristic treatments. It is distinguished by its very short anthers and shiny black mature fruits with strongly reflexed calyx lobes and usually two to four (rarely none or as many as six) sclerotic granules per fruit. Leaf shape and pubescence can vary considerably throughout its range, and there are some suspected cases of introgression with other species such as S. nigrescens or S. pseudogracile. The name S. nigrum has been misapplied to S. americanum (for example, A. E. Radford et al. 1968). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 14. | FNA vol. 14. |
Parent taxa | Solanaceae > Solanum | Solanaceae > Solanum |
Sibling taxa | ||
Synonyms | S. nigrum subsp. schultesii | S. nigrum var. americanum, S. nigrum var. nodiflorum, S. nodiflorum, S. ptychanthum |
Name authority | Linnaeus: Sp. Pl. 1: 186. (1753) | Miller: Gard. Dict. ed. 8 Solanum no. 5. (1768) |
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