Solanum viarum
Solanum rostratum
tropical soda apple
buffalo berry, buffalo-bur, buffalobur nightshade, horned nightshade, spiny nightshade
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.
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.
extra-axillary, sessile or nearly so, unbranched, 3–5-flowered.
extra-axillary, unbranched, 5–12-flowered, 4–11 cm.
0.7–1.1 cm in flower, 1–2 cm in fruit.
0.5–1.5 cm in flower, erect and 0.5–1.5 cm in fruit.
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.
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.
light green mottled with dark green when young, yellow when ripe, globose, (1.5–)2–3 cm diam., glabrous, without sclerotic granules.
brown, globose, 1–1.2 cm diam., glabrous, dry, without sclerotic granules.
reddish brown, flattened, 2–3 × 2–2.5 mm, minutely pitted.
dark brown, flattened, 2–3 × 1.8–2 mm, minutely pitted and irregularly ridged.
= 24.
= 24.
Solanum viarum
Solanum rostratum
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.)
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.)
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