Solanum seaforthianum
Solanum rostratum
Brazilian nightshade
buffalo berry, buffalo-bur, buffalobur nightshade, horned nightshade, spiny nightshade
petiolate;
petioles twining around supports, 1–4 cm;
blade simple to compound, elliptic to broadly ovate, (2–)3.5–10(–13) × (1–)2–9(–11) cm, margins entire to divided with up to 4 pairs of leaflets, leaflet margins entire, base truncate or slightly cordate.
petiolate;
petiole 2–10 cm;
blade simple to twice-compound, ovate to elliptic, (2–)4–16 × 3–12 cm, margins lobed to 1–2 times divided with 2–4 main leaflets per side, leaflets with deep, rounded lobes, base truncate to subcordate.
terminal, becoming lateral, extra-axillary, much-branched, to 100+-flowered, to 25+ cm.
extra-axillary, unbranched, 5–12-flowered, 4–11 cm.
inserted into small sleeve on inflorescence axis, 0.8–1.4 cm in flower and fruit.
0.5–1.5 cm in flower, erect and 0.5–1.5 cm in fruit.
radially symmetric;
calyx not accrescent, unarmed, ca. 0.5 mm, nearly truncate, glabrous or sparsely pubescent on lobe tips;
corolla purple, stellate, 1–2.5 cm diam., with sparse interpetalar tissue;
stamens unequal due to unequal filaments;
anthers ellipsoidal, 2–3 mm, dehiscent by terminal pores;
ovary glabrous.
bilaterally symmetric;
calyx accrescent and tightly covering fruit, densely prickly or bristly, 7.5–12.5 mm, densely stellate-pubescent, lobes linear to lanceolate;
corolla yellow, rotate-pentagonal, 1.5–3.5 cm diam., with abundant interpetalar tissue;
stamens unequal, lowermost much longer and curved;
anthers narrow and tapered, dehiscent by terminal pores, short anthers 4, yellow, 6–8 mm, longer anther reddish or purplish, 10–14 mm;
ovary glabrous.
bright shiny red, globose, 0.8–1.5 cm diam., glabrous, without sclerotic granules.
brown, globose, 1–1.2 cm diam., glabrous, dry, without sclerotic granules.
pale yellowish tan, flattened, 4–4.5 × 2.5-3 mm, minutely pitted.
dark brown, flattened, 2–3 × 1.8–2 mm, minutely pitted and irregularly ridged.
or scrambling vines, woody, unarmed, to ca. 3 m, glabrous or sparsely pubescent, hairs white, unbranched, ca. 0.2 mm.
= 24.
= 24.
Solanum seaforthianum
Solanum rostratum
Solanum seaforthianum is widely cultivated as an ornamental and sporadically escapes in Florida. A similar species with twining petioles, S. laxum Sprengel, is occasionally cultivated in California. It is distinguished from S. seaforthianum by having tufts of hairs in the vein axils of the abaxial leaf surfaces, white rather than violet corollas, and equal stamens.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Solanum rostratum is widespread in the central Mexican highlands from Chihuahua and Coahuila to Puebla and Oaxaca, and its native range likely extends from Mexico City north to the United States Great Plains. It is widely introduced outside this presumed area of origin.
Solanum rostratum is considered a noxious weed in several states. It is often invasive in gardens, pastures, and disturbed areas. The plants are extremely spiny, and there are reports of pigs being poisoned by eating the berries and roots. This species is thought to be the original host of the Colorado potato beetle (Leptinotarsa decemlineata) before potatoes were widely cultivated in the western and central United States. The beetle then adopted potatoes as its primary host and rapidly spread eastward.
(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, 
IL Wildflowers, 
KS Wildflowers, 
LA Plants, 
MD Biodiversity, 
MI Flora, 
MN Wildflowers, 
MO Plants, 
PNW Herbaria 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
