Solanum elaeagnifolium
Solanum viarum
horse nettle, silver-leaf nightshade, white horse-nettle
tropical soda apple
petiolate;
petiole 1–5 cm;
blade simple, lanceolate to oblong, 5–15 × 0.5–3 cm, margins undulate, subentire to sinuate or shallowly lobed, lobe margins entire, base truncate to cuneate.
petiolate;
petiole 3–6 cm;
blade simple, ovate to suborbiculate, 7–10(–20) × 6–8(–15) cm, margins coarsely lobed with 3–5 lobes per side, lobe margins entire to coarsely toothed, base truncate to cordate.
extra-axillary, unbranched, 3–5(–7)-flowered, 3–5 cm.
extra-axillary, sessile or nearly so, unbranched, 3–5-flowered.
1–3 cm in flower, reflexed and 1–3 cm in fruit.
0.7–1.1 cm in flower, 1–2 cm in fruit.
radially symmetric;
calyx not accrescent, unarmed or with sparse prickles, 5–10 mm, densely silvery-stellate-pubescent, lobes linear-lanceolate;
corolla pale to deep blue or violet, rarely white, pentagonal-stellate, 2–3(–3.5) cm diam., with abundant interpetalar tissue;
stamens equal;
anthers narrow and tapered, 6–9 mm, dehiscent by terminal pores;
ovary glabrous to densely stellate-pubescent.
radially symmetric;
calyx somewhat accrescent, unarmed or sparsely prickly, 3–4 mm, densely pubescent, lobes triangular;
corolla greenish or whitish, stellate, 1.5–2.5 cm diam., without interpetalar tissue;
stamens equal;
anthers narrow and tapered, 5.5–7(–10) mm, dehiscent by terminal pores;
ovary densely pubescent, hairs glandular and eglandular.
yellow to orange, drying brown or black, globose, 0.5–1.5 cm diam., glabrous, without sclerotic granules.
light green mottled with dark green when young, yellow when ripe, globose, (1.5–)2–3 cm diam., glabrous, without sclerotic granules.
yellowish, flattened, 3–5 × 2–4 mm, minutely pitted.
reddish brown, flattened, 2–3 × 2–2.5 mm, minutely pitted.
= 24, 48, 72.
= 24.
Solanum elaeagnifolium
Solanum viarum
Solanum elaeagnifolium has a disjunct native distribution. It occurs in arid regions of the southwestern United States and Mexico and also in Argentina, Chile, Paraguay, and Uruguay. North American plants are diploid, whereas those in Argentina are diploid, tetraploid, or hexaploid. It is invasive and considered a noxious weed in 21 states in the flora area as well as in many tropical and subtropical regions worldwide. It is toxic to livestock and can form large, rhizomatous patches that are difficult to eradicate.
A white-flowered form has been recognized as Solanum elaeagnifolium forma albiflorum Cockerell.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
In the United States, Solanum viarum was first collected in Florida in 1988 and has subsequently become an aggressive and invasive species in the Southeast. It is on the Federal Noxious Weeds List and is classified as a noxious weed or plant pest in many states. Cattle and other animals eat the fruits and spread the seeds through their feces, and the seeds are coated with a sticky substance that makes them adhere to farm equipment when the plants are mowed. It can form large patches that are difficult to eradicate due to their extensive root systems and sharp prickles. It is a major agricultural pest and a threat to native ecosystems.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
- Local floras:
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
IL Wildflowers, 
KS Wildflowers, 
LA Plants, 
MD Biodiversity, 
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
