Nicotine is a naturally occurring alkaloid found in certain plants, particularly those in the Solanaceae (nightshade) family. Chemically, it acts as a stimulant and is well known for its presence in tobacco (Nicotiana species), where it contributes to the addictive properties of smoking and chewing products.
In plants, nicotine functions as a natural defense mechanism. It acts as a neurotoxin to insects and herbivores, deterring them from feeding on the plant. This defensive role helps explain why nicotine is concentrated in the leaves, where feeding is most likely to occur.
The highest concentrations of nicotine are found in cultivated tobacco (Nicotiana tabacum) and wild tobacco (Nicotiana rustica), with N. rustica containing significantly more. Other plants like tomatoes, potatoes, eggplants, and peppers contain trace amounts of nicotine, though not at levels that affect humans.
Nicotine can also be found in other genera within the nightshade family, such as Duboisia, which is used in both traditional medicine and modern pharmaceuticals. These plants share a similar alkaloid profile, even if they are not used recreationally like tobacco.
While nicotine has a harmful reputation due to its addictive nature in tobacco products, it is also used in some insecticides and has been studied for potential therapeutic uses in neurological research. However, its toxic effects at high doses make it a tightly regulated substance.
The presence of nicotine across a wide range of plant species shows its evolutionary value as a chemical defense. In agricultural science, understanding nicotine distribution also helps in managing pest resistance and food safety in related crops.
Plants With High Nicotine Content
Tobacco (Nicotiana tabacum)
Tobacco, the primary commercial source of nicotine, is an annual plant native to the Americas, growing 3–6 feet tall in USDA zones 8–11. Its broad, green leaves contain nicotine at 0.6% to 9.0% of dry weight, synthesized in the roots and stored in leaves. Used for smoking, chewing, and as a pesticide, its sticky, hairy leaves and pink or white tubular flowers are distinctive. Identify it by its large, lance-shaped leaves and clusters of trumpet-shaped flowers. Its high nicotine content makes it the benchmark for comparison.
Wild Tobacco (Nicotiana rustica)
Wild tobacco, also called mapacho, is a robust annual native to South America, growing 2–5 feet tall in zones 8–11. It has higher nicotine content than N. tabacum, up to 18.76% of dry weight, concentrated in its heart-shaped, hairy leaves. Traditionally used in indigenous rituals and for medicinal purposes, its potent leaves are also used as a natural insecticide. Identify it by its smaller, rounder leaves compared to commercial tobacco and yellowish-green flowers. Its intense nicotine levels make it unsuitable for casual use.
Tree Tobacco (Nicotiana glauca)
Tree tobacco is a drought-resistant, evergreen shrub native to South America, growing 6–20 feet tall in zones 8–11. Its blue-green, waxy leaves and yellow tubular flowers contain significant nicotine, though less than N. tabacum, typically 0.5–2% of dry weight. Used as an ornamental and for pesticidal properties, it’s toxic if ingested. Identify it by its tall, woody stems, smooth leaves, and clusters of drooping flowers. Its adaptability to arid conditions makes it common in disturbed soils.
Jasmine tobacco (Nicotiana sylvestris)
Nicotiana sylvestris, a wild tobacco species native to South America, is a tall, ornamental annual or biennial, reaching 4–6 feet in zones 8–11. Its large, sticky, lance-shaped leaves and long, white, trumpet-shaped flowers contain moderate nicotine levels, around 0.5–2% of dry weight, used in tobacco breeding programs. Its fragrant, night-blooming flowers attract pollinators. Identify it by its towering habit and rosette of broad leaves, ideal for ornamental gardens but toxic if consumed.
Benthi (Nicotiana benthamiana)
Nicotiana benthamiana, a wild tobacco native to Australia, is a small, annual plant, 1–4 feet tall, used widely in plant biology research. Its oval, sticky leaves contain moderate nicotine levels, approximately 0.5–1.5% of dry weight, as a defense mechanism. Its small, white flowers bloom in clusters. Identify it by its delicate, branching habit and soft, hairy foliage, distinct from larger tobacco species. Its research value lies in its susceptibility to genetic modification, not commercial nicotine production.
Eggplant (Solanum melongena)
Eggplant, a tropical perennial grown as an annual in zones 4–11, produces edible, purple fruit and has nicotine in its leaves, seeds, and skin, at about 100 nanograms per gram (0.0001 mg/g). A member of the Solanaceae family, its broad, lobed leaves and purple flowers resemble tobacco. Identify it by its bushy, 2–4-foot stature and glossy fruit. While safe to eat, its leaves are not consumed due to nicotine and other alkaloids, making it a minor source compared to tobacco.
Tomato (Solanum lycopersicum)
Tomato, a popular fruiting annual or perennial in zones 3–11, contains trace nicotine, primarily in its leaves and green, unripe fruit, at about 40 nanograms per gram in green tomatoes and 4–10 ng/g in ripe ones. Its heart-shaped leaves and yellow, star-shaped flowers mark it as a Solanaceae member. Identify it by its sprawling vines and juicy, red-to-yellow fruit. Nicotine in leaves deters pests, but edible fruit poses no health risk due to minimal levels.
Potato (Solanum tuberosum)
Potato, a starchy tuber crop grown as an annual in zones 3–10, has low nicotine levels, around 7 nanograms per gram, concentrated in its leaves and sprouts, with less in the edible tubers. Its green, compound leaves and white or purple flowers are typical of Solanaceae. Identify it by its low, bushy growth and underground tubers. Avoid consuming green sprouts or leaves due to nicotine and other toxic alkaloids like solanine. Its nicotine content is negligible for dietary impact.
Bell Pepper (Capsicum annuum)
Bell pepper, an annual or perennial vegetable in zones 4–11, contains trace nicotine, around 7–9 nanograms per gram, mostly in its leaves and slightly in its fruits (green, red, or yellow). Its glossy, green leaves and white flowers are Solanaceae traits. Identify it by its blocky, colorful fruit and upright, 1–3-foot plants. Nicotine levels are too low to affect consumption, but leaves are not eaten. It’s valued for culinary versatility, not nicotine content.
Jimsonweed (Datura stramonium)
Jimsonweed, a toxic annual weed in zones 3–9, grows 1–5 feet tall and contains low nicotine levels, around 0.5–1.5% of dry weight, alongside other alkaloids like atropine. Its large, toothed leaves, white or purple trumpet flowers, and spiky seed pods are distinctive. Identify it by its foul odor and coarse, branching habit. Used historically as a hallucinogen, it’s highly poisonous and not cultivated. Its nicotine content is secondary to its other toxic compounds.
Deadly Nightshade (Atropa belladonna)
Deadly nightshade, a perennial weed in zones 5–9, grows 2–4 feet tall with dark green, ovate leaves, purple bell-shaped flowers, and shiny black berries. It contains trace nicotine, less than 0.5% of dry weight, overshadowed by toxic alkaloids like atropine. Identify it by its solitary, drooping flowers and glossy, poisonous berries. Not used for nicotine due to its extreme toxicity, it’s a wild plant to avoid. Its presence in disturbed soils signals caution.
Ground Cherry (Physalis peruviana)
Ground cherry, an annual or perennial in zones 4–8, grows 1–3 feet tall with heart-shaped leaves and yellow, bell-shaped flowers encased in papery husks. Its leaves contain trace nicotine, around 10–20 nanograms per gram, as a pest deterrent, while its edible, golden fruit is nicotine-free. Identify it by its lantern-like husks and sprawling habit. Used for culinary purposes like jams, its nicotine content is minimal and confined to non-edible parts.
Bittersweet Nightshade (Solanum dulcamara)
Bittersweet nightshade, a perennial vine in zones 4–8, grows 2–8 feet long with purple, star-shaped flowers and red, oval berries. It contains trace nicotine, around 10–20 nanograms per gram, in its stems and leaves, alongside toxic solanine. Identify it by its climbing habit, lobed leaves, and drooping flower clusters. A common weed, it’s toxic if ingested and not used for nicotine. Its bright berries and sprawling growth make it recognizable in wild settings.
Coyote Tobacco (Nicotiana attenuata)
Coyote tobacco, a wild annual native to western North America, grows 2–4 feet tall in USDA zones 7–10. Its slender, sticky leaves and small, white, tubular flowers contain nicotine at approximately 0.5–2% of dry weight, used as a natural insect repellent. Traditionally smoked by Native American tribes, it’s also studied for ecological interactions. Identify it by its narrow, lance-shaped leaves, delicate flowers, and preference for dry, rocky soils. Its lower nicotine content compared to N. rustica makes it less commercial but valuable in research.
Langsdorff’s tobacco (Nicotiana langsdorffii)
Nicotiana langsdorffii, a South American annual or short-lived perennial, grows 2–5 feet tall in zones 8–11. Its ovate, sticky leaves and nodding, green tubular flowers with yellow tips contain nicotine at around 0.3–1% of dry weight, serving as a pest deterrent. Popular as an ornamental for its unique flower color, it’s toxic if ingested. Identify it by its vibrant green flowers and upright, branching habit, ideal for garden borders. Its nicotine content is modest but notable in ecological studies.
Manyflower tobacco (Nicotiana acuminata)
Nicotiana acuminata, a wild tobacco native to South America and naturalized in parts of North America, is an annual growing 2–3 feet tall in zones 8–10. Its narrow, pointed leaves and white, star-shaped flowers contain nicotine at approximately 0.5–1.5% of dry weight. Used in traditional medicines and as a pesticide, it’s less common in cultivation. Identify it by its slender, tapering leaves and small, open flower clusters, thriving in disturbed soils. Its nicotine is secondary to its ecological role.
Desert tobacco (Nicotiana obtusifolia)
Nicotiana obtusifolia, also called desert tobacco, is a native North American annual or perennial, growing 1–3 feet tall in zones 7–10. Its rounded, sticky leaves and creamy white, tubular flowers contain nicotine at about 0.4–1.2% of dry weight, used by indigenous groups for ceremonial purposes. Identify it by its compact, bushy form and blunt-tipped leaves, common in arid regions. Its nicotine content supports its use as a natural insecticide but is too low for commercial extraction.
Petunia (Petunia hybrida)
Petunia, a popular ornamental annual in zones 9–11, grows 6–18 inches tall with colorful, trumpet-shaped flowers in shades of purple, pink, or white. Its hairy, oval leaves contain trace nicotine, around 5–10 nanograms per gram, as a pest deterrent, typical of the Solanaceae family. Identify it by its vibrant, funnel-shaped blooms and sticky foliage, ideal for hanging baskets or borders. While safe for gardening, its leaves are not consumed due to low-level alkaloids, including nicotine.
Chili Pepper (Capsicum frutescens)
Chili pepper, a perennial grown as an annual in zones 4–11, produces spicy fruits and grows 1–4 feet tall. Its green, lance-shaped leaves and white flowers contain trace nicotine, around 7–10 nanograms per gram, mostly in leaves, with negligible amounts in fruits. Identify it by its glossy fruits (red, green, or yellow) and upright habit, common in culinary gardens. Its nicotine is minimal, posing no dietary risk, but leaves are avoided due to alkaloids.
Goji Berry (Lycium barbarum)
Goji berry, a deciduous shrub in the Solanaceae family, grows 3–6 feet tall in zones 3–10, producing red-orange berries used in health foods. Its narrow, gray-green leaves contain trace nicotine, around 5–15 nanograms per gram, as a defense mechanism. Identify it by its arching branches, small purple flowers, and elongated berries. While berries are edible, leaves are not consumed due to low nicotine and other alkaloids. It thrives in well-drained soil and full sun.
Wolfberry (Lycium chinense)
Wolfberry, closely related to goji berry, is a deciduous shrub, 3–8 feet tall, in zones 6–9, with small喧0.00001% of dry weight nicotine in its leaves and stems, around 5–10 nanograms per gram. Its small, purple flowers and red berries are edible, but leaves are not. Identify it by its sprawling, vine-like growth and narrow leaves, common in Asian landscapes. Its nicotine content is negligible for consumption.
Henbane (Hyoscyamus niger)
Henbane, a toxic biennial or annual weed in zones 4–8, grows 1–3 feet tall with fuzzy, toothed leaves and bell-shaped, yellowish flowers. It contains low nicotine levels, around 0.1–0.5% of dry weight, alongside other alkaloids like hyoscyamine. Historically used in medicine, it’s highly poisonous. Identify it by its sticky, foul-smelling foliage and solitary flowers, found in waste areas. Its nicotine content is minor compared to its other toxins, making it unsuitable for use.
Mandrake (Mandragora officinarum)
Mandrake, a perennial herb in zones 6–8, grows 6–12 inches tall with rosettes of broad leaves and purple or white flowers. Its roots and leaves contain trace nicotine, around 5–10 nanograms per gram, with stronger alkaloids like scopolamine. Toxic and historically medicinal, it’s identified by its root’s humanoid shape and low, spreading habit. Not used for nicotine due to its toxicity, it’s a rare garden plant requiring caution.
Indian tobacco (Nicotiana quadrivalvis)
Nicotiana quadrivalvis, a North American native tobacco, is an annual growing 1–3 feet tall in zones 7–10. Its oval, sticky leaves and white or pale pink flowers contain nicotine at about 0.5–1.5% of dry weight, used in traditional smoking blends. Identify it by its compact habit and small, star-shaped flowers, common in prairies. Its moderate nicotine content makes it a minor ceremonial plant, not commercially significant.
Tree tobacco (Nicotiana gossei)
Nicotiana gossei, an Australian native annual, grows 2–4 feet tall in zones 8–11, with broad, sticky leaves and pinkish-white flowers. Its nicotine content, around 0.3–1% of dry weight, supports pest resistance. Ornamental and occasionally used in research, it’s identified by its large, soft leaves and open flower clusters. Its nicotine levels are lower than cultivated tobacco, limiting its practical use.
Tomatillo (Physalis philadelphica)
Tomatillo, an annual in zones 4–8, grows 2–4 feet tall with green, lantern-like husks encasing tart, green fruits. Its leaves contain trace nicotine, around 5–15 nanograms per gram, as a pest deterrent. Identify it by its papery husks and yellow flowers with dark centers, typical of Solanaceae. Edible fruits are nicotine-free, but leaves are avoided due to alkaloids. It’s valued for salsas, not nicotine.
Habanero Pepper (Capsicum chinense)
Habanero pepper, a fiery-hot perennial grown as an annual in zones 4–11, reaches 1–3 feet tall with wrinkled, colorful fruits. Its leaves contain trace nicotine, around 7–10 nanograms per gram, negligible in its spicy fruits. Identify it by its crinkled, green-to-orange fruits and white flowers. Used in culinary dishes, its nicotine is irrelevant to consumption, with leaves avoided due to minor alkaloid content.