Solanum americanum
Solanum triquetrum
American black nightshade, American black or common or West Indian nightshade, glossy nightshade, little white nightshade, small-flower nightshade, white nightshade
Texas nightshade
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 0.3–1.2 cm;
blade simple, deltate to hastate or triangular, sometimes linear, (1–)1.8–5 × (0.3–)1–3.5 cm, margins entire to basally 2-lobed, lobe margins entire, base truncate to subcordate or hastate.
extra-axillary or leaf-opposed, unbranched, usually umbel-like, 3–10-flowered, 0.5–3 cm.
terminal or lateral, leaf-opposed or occasionally extra-axillary, unbranched or occasionally forked, 3–6-flowered, 1–3 cm.
erect or spreading, 0.3–1 cm in flower, to 1.5 cm in fruit.
inserted into small sleeve on inflorescence axis, 0.6–1.2 cm in flower, 1–1.5 cm in 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, 2.5–3.5 mm, glabrous to sparsely pubescent, lobes triangular-acuminate;
corolla white or tinged with purple, often with shiny green or greenish white eye, stellate, 1.5–2 cm diam., without interpetalar tissue;
stamens equal;
anthers oblong, slightly tapered, 3.5–4 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.
bright shiny red, globose, 1–1.5 cm diam., glabrous, without sclerotic granules.
pale yellow to brown, 1–1.5 × 0.5–1.5 mm, minutely pitted.
reddish brown, plump-reniform to flattened, ca. 4 × 2.5 mm, minutely pitted.
, semiwoody or scramblers with enlarged woody base, to 2 m, occasionally erect subshrubs to 0.5 m, unarmed, glabrous to densely pubescent, hairs usually ascending and pointing distally on stems, weak, unbranched, to 0.5 mm.
= 24.
= 24.
Solanum americanum
Solanum triquetrum
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.)
Solanum triquetrum is widespread in central, southern, and western Texas. It could be confused with S. dulcamara, which also has shiny green dots at the corolla lobe bases, but the flowers of S. triquetrum are white and the leaves more sharply triangular. Leaf shape and size in S. triquetrum are extremely variable (S. Knapp 2013).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
- Local floras:
BC, 
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OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
LA Plants, 
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USDA Plants Database- LBJ Wildflower Center
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