Tree Tobacco (not native)

Nicotiana glauca

tree with branches and sporadic leaves
Harbaugh Seaside Trails | October 2018

Tree tobacco (Nicotiana glauca) is a small, open tree with rubbery, silvery-blue leaves and terminal clusters of tubular, yellow flowers. It blooms frequently along roadways, trails, abandoned fields and other disturbed areas.

Tree tobacco is native to South America. It was planted around the world as an ornamental garden plant and jumped the garden fence into the native wildlands of many countries. It is classified as invasive in California.

Although Native Americans are said to have consumed tree tobacco and to have smoked the leaves for ceremonial and spiritual purposes, smoking tree tobacco induces vomiting, and ingestion causes seizures and even death. Most authorities agree that it is unwise to ingest any part of this plant.

Other Common Names:

Tobacco tree, mustard tree, juanloco, palo loco

Description 4,23,34,59

Tree tobacco is a small, open tree usually less than 20 feet (6 m) tall with arching or drooping branches. It is variously described as “spindly”4 and “straggling” 23, and  “rangy”.444 The stems and leaves are blueish green, dusted with fine, waxy particles (glaucous). The leaves are generally oval in shape, shorter than eight inches (20 cm), and often with an acute or pointed tip. Petioles are somewhat shorter than the leaves. The leaf surface is smooth and rubbery to touch, and margins lack teeth.

Flowers occur in large, branched, terminal clusters that may contain blossoms and seed pods in all stages of development and in all seasons of the year. Flowers are symmetrical and bisexual. The calyx is five-lobed and persists around developing fruits. Five yellow petals are united into a long narrow tube, constricted before the mouth where the short lobes flare outward. Flowers are up to 1½ inches (4 cm) in length and are often tinged with green, especially near the mouth. There are five greenish-white stamens that do not project from the flower mouth; when open to shed pollen, the anthers resemble little mushroom caps. There is one pistil with a superior ovary and one style that holds the stigma just beyond the anthers – close to the flower mouth. The stigma is green with two lobes. The major bloom period is March – Sept.7 but flowers and seeds are found all year.

The fruit is a smooth, ovoid capsule, about a ½ inch (1.3 cm) long, surrounded by the brown calyx, which may be intact or split. The capsule splits from the tip, releasing numerous tiny brown seeds that are irregular in shape (mostly oval or D-shaped) and have a sculptured surface.

close up of stem

Bluish foliage dusted with waxy particles | Pole road | August 2018

large yellow seed pods

Pole Road | November 2011

thin branches with leaves

West Basin | October 2018


Tree tobacco is native to central and northwest Argentina and Bolivia, from where it was widely introduced around the world, primarily as a garden ornamental. It rapidly colonized many native habitats and is considered invasive in parts of Europe and South Africa. In North American, it has become established in many southwestern states, Baja California and mainland Mexico.443

It was first recorded in California in the late 19th century, although how it was introduced is unclear. It may have been introduced accidentally as a contaminant in grain23 or purposefully as an ornamental183 or as a source of smoking tobacco.23 As elsewhere, the plant quickly escaped into disturbed areas and wildlands.

In California tree tobacco is rated as a “moderate” invader;183 it is found in the southwestern portion of the state and the Central Valley, primarily below 4000 feet (1200 m).7,89 In spite of eradication efforts in the Reserve, as of 2018, tree tobacco persists along the Pole Road, at trailheads and occasionally elsewhere.

Classification 2,44,143

Tree tobacco is a dicot angiosperm in the tobacco family (or nightshade family or potato family; Solanaceae). Members of this family have five petals that are fused into a tube, at least at the base. Sometimes the petals or lobes are reflexed. Fruits are either a berry or a capsule.  Many members of this family contain alkaloid compounds which may be toxic or narcotic; these include scopolamine, atropine, and nicotine.

The tobacco family includes many well-known food and ornamental species such as tomato, pepper, potato, petunia and night-blooming jasmine. The family also includes tobacco and belladonna. Eight species in this family have been reported from the Reserve.48 The six natives include  Parish’s nightshade (Solanum parishii), the threatened California box thorn, Lycium californicum (CNPS list 4B) and Sacred Datura (Datura wrightii).

Jepson eFlora Taxon Page
leaf pods opening on branch

Pole road | November 2011

leaf pods on branch

Pole road | August 2018

Tree growing beside basin

West Basin | October 2018

Ecology 443,445

Tree tobacco has the open structure and long, tubular flowers that favor hummingbirds over other pollinators, and in its native habitat, tree tobacco is strictly pollinated by hummingbirds. In California too, hummingbirds are the primary pollinator, with bees and other insects making rare visits, with occasional self-pollination. This specialization is unusual for a successful non-native invader, for which a broad range of potential pollinators in its new habitat broadens its chance of successful reproduction.

The pretty flowers of tree tobacco and their year-round production of copious nectar have made tree tobacco valuable as a garden ornamental, especially in bird gardens. On the other hand, there is some evidence that in the wild, the long and consistent period of nectar supply allows tree tobacco to out-compete native plants for hummingbird pollinators. In areas of the Santa Monica Mountains where tree tobacco “forests” are established, there are few if any native hummingbird-pollinated plants – plants such as California fuchsia (Epilobium californicum) and hummingbird sage (Salvia spathaceae) – even though these plants are abundant in nearby areas without tree tobacco. There is a brief mention of similar pollinator-competition between tree tobacco and prickly pear183 and more direct evidence from a study of an invasive species of impatiens in Europe.446

leaf blooming on branch

Cardiff cove | October 2018

tall branches with leaves

Rios trailhead | August 2018

opening of seed pod

Inside a flower with a knob-shaped pistil and mushroom-shaped anthers | Pole road | August 2018

Human Uses  

Like many plants in the nightshade family, tree tobacco contains alkaloids – primarily anabasine, chemically similar to nicotine. There are reports of tree tobacco used by native Americans in California both for medicinal purposes and for rituals, smoking, and consumption.282 Locally, the Luiseño administered tree tobacco topically on wounds and as a fumigant to relieve earaches.17

It is also known that all parts of this plant are toxic, causing vomiting, hallucinations, respiratory failure, and death.59,66 The California Poison Control System rates the toxicity as major.209 Most modern references warn against smoking or eating any part of the plant11,15,66 – even the flower nectar.59

In spite of its invasive tendencies, tree tobacco is often recommended for flower gardens, both for the long display of pretty yellow flowers and for the copious nectar which attracts hummingbirds.441,445

opening of seed pod

Pole road | August 2018

plant with deep green leaves

Cardiff cove | October 2018

thin stems holding many leaves

Rios trailhead | September 2018

Interesting Facts 21

Tree tobacco is in the genus Nicotiana, the name of which is clearly related to the chemical nicotine, present in plants of this genus. Both the chemical and the genus were named after a French diplomat and scholar, Jean Nicot de Villemain who is thought to have introduced tobacco to France about 1560. It was first introduced as a powder to inhale as a cure for headaches; it later evolved into snuff and became identified with the pleasure of nobility.

(The practice of smoking tobacco leaves began in the Americas over two thousand years ago and didn’t spread to Europe until the Spaniards arrived.56)

two men harvesting tobacco

A weed wrench is needed to pull the roots | Pole road | September 2013

man holding dried tree branch

Pole road | September 2013

tiny brown shrivelled seeds

Tiny seeds, scale units are one millimeter | Pole Road | August 2018

Photo Gallery