Nicotiana glauca Graham


Solanaceae (Nightshade Family)


South America


Tree Tobacco 

                                     December Photo


Plant Characteristics:  Erect glabrous, glaucous shrub or small tree, 2-6 m. tall, with loose branching and open panicles; lvs. ovate, entire to repand, 3-8 (-15) cm. long, on long petioles; fls. greenish-yellow, loosely paniculate; calyx ca. 1 cm. long, unequally 5-toothed; corolla tubular, 3-4 cm. long, somewhat contracted at throat, minutely pubescent, with narrow limb; stamens +/- equal, filaments attached below middle of tube; caps. ovoid, 10-12 mm. long, 4-valved above.


Habitat:  Common, natur. in waste places, on burns, etc., below 3000 ft.  Spring and summer.


Name:  See N. clevelandii for explanation of genus name.  Glauca is from the Greek and means "bluish-gray." referring to the leaves.  (Dale 193).


General:  Fairly common in the study area.   Photographed along Back Bay Dr.  (my comments).     This plant was introduced from South America in Spanish days.  One version is that it arrived here when the padres imported grain.  Another has it that it was purposely brought by the padres as a source for smoking tobacco.  It is poisonous to ingest either cooked or raw.  (Dale 193).        No insects sequester nicotine, (hold it in their system and become poisonous themselves), a few have become tolerant and can eat the leaves.   Insects that eat the leaves of poisonous plants and are not poisonous themselves are not brightly colored; those that sequester poison are brightly colored.  (Native plant class taught through Coastline College by Dave Bartranger, spring 1985).      The Gabrielinos and other tribes mixed Nicotiana spp. with lime from seashells and ate it.  A kind of intoxication resulted though the main effect seems to have been vomiting.      Some species of tobacco were raised by the Indians in a semi-horticulture.  Special plots were chosen, the brush was burned, seeds were planted in the ashes and the plot was tended by thinning and weeding.  Few other plants were planted, as the "wild acorn industry" was so well developed. (Heizer and Elsasser 143,144).      Nicotine, a chemical found in tobacco, is poisonous to insects and in sufficient amounts, to human beings.  Yet nicotine has no effect on the tobacco plant.  In fact, scientists have grown healthy tobacco plants that contain no nicotine at all.  Of course, it is impossible to say for certain that a poisonous chemical is truly useless to a plant.  In time we may discover that many plant poisons serve important functions in the plants that manufacture them, but for the time being the most honest answer to the question "Why are there poisonous plants?" is simply that nobody knows.  (Eshleman 15).          An interesting phenomenon associated with  foreign plant communities is the virtually complete absence of native hummingbird-pollinated plants in the areas long dominated by tree tobacco.  Such common natives as purple sage Salvia leucophylla, and pitcher sage S. spathacea, California fuchsia Zauschneria californica, heartleaved penstemon Keckiella cordifolius, and other penstemons are virtually absent from large areas populated by tree tobacco in the south coastal valleys and canyons.  Evidently the ubiquitous tobacco, with its year round production of yellow flower tubes supplying nectar, weans away many of the local hummingbirds from the seasonal flowers of native species.  Perhaps other plant species "designed" to attract the hummingbird simply do not receive sufficient pollination to maintain a local population.  Where tree tobacco is still relatively scarce in side canyons, any or all of the normal wild hummingbird plant species usually can be found.  (No author listed, "Control of the Aliens, Unnatural Plant Communities in the Santa Monica Mountains"  FREMONTIA, A Journal of the Native Plant Society  July 1989 22-24).       Humans are able to smoke tobacco only because the body is capable of breaking down and eliminating the alkaloid nicotine rather than accumulating it.  Anabasine is very similar to nicotine and is the principal alkaloid in N. glauca.  (Fuller 339).       This plant is supposed to have been introduced from Buenos Aires and old inhabitants remember the time when but one or two plants were known.  In thirty years if has spread rapidly, and is now exceedingly common.  (Parsons 133).       Parson's book was published in 1909.  (my comment).       In August 1991 I observed a ground squirrel eating the flowers of N. glauca.  Apparently the flowers are not poisonous.  (my comment).        In August 1991, I   found a clump of the California Fuchsia, Zauschneria californica, and observed a hummingbird feeding on the nectar of the flowers.  To the best of my knowledge, this is the only location of this species in the upper bay area, while there are many N. glauca.  Whether the lack of the Fuchsia in the upper bay is as noted above from Fremontia or whether N. glauca is a more robust species I do not know.  (my comment).        Nicotine improves concentration and memory.  Ask any smoker.  There are actually nicotinic receptors in your brain that are binding sites for both nicotine and acetylcholine, the neurotransmitter of memory and learning. Nicotine enhances nerve cell communication and increases the production of neurotransmitters.  Researchers are exploring the use of nicotine-not smoking-as a brain booster.  Nicotine-like compounds are being studied as a treatment for Alzheimer’s disease, as such substances have proven effective in restoring memory.  There have been reports of people with memory loss successfully using nicotine patches to improve memory.  (Whitaker, Dr. Julian “Does Nicotine Help With Memory Loss?” Health and Healing February 2002 Vol. 12 No.2 p. 2).


Text Ref:  Dale 193; Hickman, Ed. 1072; Munz, Calif. Flora 602; Munz, Flora So. Calif. 835.

Photo Ref:  Dec 1 82 # 34 A; Dec 2 82 # 14.

Identity: by R. De Ruff.

Computer Ref:  Plant Data 285.

No plant specimen.

Last edit 7/10/03.  

                                         December Photo