Solanum triflorum
Solanum interius
cut-leaf nightshade, three flower nightshade
deadly nightshade, plains black nightshade, plains black or deadly nightshade
petiolate;
petiole 0.5–2.5 cm;
blade simple, elliptic to oblong, 2–5 × 1–3 cm, margins shallowly lobed to deeply and regularly pinnatifid with 3–6 lobes per side, lobe margins entire or occasionally coarsely lobed, base cuneate and decurrent.
petiolate;
petiole 0.5–3.5 cm;
blade simple, ovate to ovate-lanceolate, 4.5–11 × 2.5–7 cm, margins entire to sinuate-dentate, base cuneate to rounded or slightly decurrent.
extra-axillary, unbranched, umbel-like, 1–6-flowered, 1–3 cm.
extra-axillary, unbranched, (2–)3–8-flowered, 2.5–3.5 cm.
spreading and 0.5–1.5 cm in flower, reflexed and 0.5–1.5 cm in fruit.
spreading in flower, recurved to reflexed in fruit, 0.5–1 cm in flower and fruit.
radially symmetric;
calyx accrescent and covering base of berry, unarmed, 2–4(–7) mm, moderately pubescent, lobes deltate, reflexed;
corolla white or light purple with green or purplish central star, stellate, 0.5–1 cm diam., with sparse interpetalar tissue;
stamens equal;
anthers narrowly ellipsoidal, 2.5–4 mm, dehiscent by terminal pores that open into longitudinal slits;
ovary glabrous.
radially symmetric;
calyx not accrescent, unarmed, 2–5 mm, sparsely pubescent, lobes lanceolate, sometimes reflexed in fruit;
corolla white, sometimes tinged with purple, with yellowish central star, stellate, 0.5–1 cm diam., without interpetalar tissue;
stamens equal;
anthers ellipsoidal, 1.8–2.5 mm, dehiscent by terminal pores that open into longitudinal slits;
ovary glabrous.
shiny dark green to purplish black, globose, 0.8–2 cm diam., glabrous, with 13–30 sclerotic granules.
shiny purplish black, globose, 1–1.5 cm diam., glabrous, with 2–4 sclerotic granules.
yellow, plump, 2–3 × 2–2.5 mm, minutely pitted.
yellowish to brown, flattened, 1.8–2 × 1.5–1.6 mm, finely reticulate.
= 24.
= 24.
Solanum triflorum
Solanum interius
Solanum triflorum is found in South America (Argentina) and is also considered to be native to central and western North America. It is occasionally adventive in the eastern United States. It is poisonous to livestock and can become a serious weed in cultivated fields, especially in the Great Plains.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Solanum interius is endemic to North America and is most common in the Great Plains and eastern Rocky Mountains. Distinctive characters are the basal flower with its pedicel articulated above the base and the very large seeds. In Texas, S. interius can be very difficult to distinguish from S. nigrescens, but S. interius usually has longer calyx lobes. Records of S. interius from Saskatchewan are actually S. emulans.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
- Local floras:
BC, 
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
Go Botany, 
KS Wildflowers, 
MI Flora, 
MN Wildflowers, 
MO Plants, 
PNW Herbaria 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
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