Solanum americanum
Solanum jamesii
American black nightshade, American black or common or West Indian nightshade, glossy nightshade, little white nightshade, small-flower nightshade, white nightshade
wild potato
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.
petiolate;
petiole 1.5–3.5 cm, sometimes with pair of pinnatifid pseudostipules at base;
blade compound, elliptic to ovate, 7–15 × 4–9 cm, margins divided into 1–4(–5) pairs of leaflets, leaflet margins entire, base attenuate.
extra-axillary or leaf-opposed, unbranched, usually umbel-like, 3–10-flowered, 0.5–3 cm.
terminal, extra-axillary, generally forked or 3-fid, 4–10(–20)-flowered, to 3 cm.
erect or spreading, 0.3–1 cm in flower, to 1.5 cm in fruit.
articulated near middle, 1.6–3 cm in flower and fruit.
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.
radially symmetric;
calyx not accrescent, unarmed, 4–6 mm, glabrous to sparsely pubescent, lobes deltate-acuminate;
corolla white, stellate, 2.8–3.5 cm diam., without interpetalar tissue;
stamens equal;
anthers oblong, slightly tapered, 5–6 mm, dehiscent by terminal pores that open into longitudinal slits;
ovary glabrous.
shiny purplish black, globose, 0.5–1 cm diam., glabrous, with (0–)2–4(–6) sclerotic granules, usually 2–4 larger and 2 smaller.
green, globose, ca. 1 cm diam., glabrous, without sclerotic granules.
pale yellow to brown, 1–1.5 × 0.5–1.5 mm, minutely pitted.
dark reddish brown, rounded, 1–2 mm diam., rugose.
= 24.
= 24.
Solanum americanum
Solanum jamesii
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.)
The tubers of Solanum jamesii have been gathered as food by Native Americans, and starch grains identified as S. jamesii from stone tools in Utah form the earliest evidence for the use of potatoes in North America (L. A. Louderback and B. M. Pavlik 2017). All other parts of the plant are toxic.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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