In Full Bloom: History and gardening glory aside, flowering tobacco is noteworthy because of its uncanny intelligence
By Allissa Bunner
Sep 14, 2019 | 7:00 AM
This week, I ran into an old flower friend. On top of being fun to grow, learning about flowering tobacco introduced me to the invisible world of plant communication chemicals. Able to change its flowers and call predators for help, Nicotiana captured my imagination. And with a long ethnobotanical and horticultural history, it would seem I’m not the only one fascinated by it.
Nicotiana is a genus of 67 herbaceous species in the nightshade family, almost entirely native to the Americas. The nightshade family, Solanaceae, is famous for the chemical compounds its members possess — like atropine, capsaicin and cocaine, to name a few. One chemical compound found in Nicotiana is the reason the plant has been propagated for thousands of years — nicotine.
In a publication titled “Evidence for Aboriginal Tobaccos in Eastern North America” by Thomas Haberman in the Journal of American Antiquity, Native American archaeological sites were scoured for evidence of tobacco in the form of seeds. It was discovered of the 14 species of tobacco native to the United States, nine of them were being cultivated in large portions of the East Coast. Although the plant was being widely used ceremonially, recreationally and medicinally by natives when Christopher Columbus came to the New World in 1492, there is evidence carved into Mayan temples that the plant had been domesticated for quite some time before that.
Dried tobacco leaves were offered by indigenous peoples to Columbus, and it didn’t take long for the plant to begin being hauled by back by the boatload to Europe. In “Medical Uses of Tobacco in History” published by Anne Charlton in the Royal Journal for Medicine, the author explains Europe’s newest import was elevated to the status of panacea, or cure all. Besides being smoked, chewed, snuffed or drank in tea, the leaves of the plant were also used for treating arthritis, cataract, colds, fevers and as a treatment for lesions, eczema and rattlesnake bites — even basal cell cancers. It was even said when a cook employed by the French ambassador Jean Nicot, the scholar for which the genus was named, nearly amputated his finger in the kitchen, the wound was bound in tobacco leaves. After changing the dressings for six days, the wound had healed entirely. In 1828, when German chemists isolated the nicotine alkaloid, the medical community began to reign in the indiscriminate prescription of tobacco in attempt to quantify its therapeutic uses and proper dosing.
The list of medicinal uses, which persisted even into the 20th century, is as long as it is ironic. The irony being that the World Health Organization states tobacco products claim 8 million lives each year. Nevertheless, the cash crop is grown in 125 countries worldwide on nearly 10 million acres of land. In 2018 the CDC reported the United States, which is the forth largest producer of the crop, processed nearly 533 million pounds of tobacco- with some 44 million of those pounds coming out of Virginia.
But tobacco isn’t just propagated for its alkaloids, Nicotiana has been a popular ornamental since the Victorian era because of its striking foliage and fragrant, showy blooms. The flower’s five fused petals come in various reds, pinks, whites, yellows and purples. It’s an easy to grow, pollinator-friendly, self-seeding annual that would be a welcome addition to any garden. Nicotiana ‘Scentsation’ from Baker Creek Heirloom seeds is my favorite so far because the plants stay petite and offer blooms in every color. That being said, one can never go wrong with the longer, tubular flowers on Southern Exposure’s 'Old Fashioned Mix.”
History and gardening glory aside, flowering tobacco is a noteworthy plant because of its uncanny intelligence. Most gardeners have had the pleasure of meeting a hornworm. With their ravenous appetites, even by caterpillar standards, they host solely on members of the nightshade family. Coyote tobacco, Nicotiana attenuata, with it's fragrant, night blooming flowers is pollinated by moths. After nectaring, the moths often lay eggs and when the eggs hatch, caterpillars begin to feed. But surprisingly, coyote tobacco has outfoxed the hornworm.
When a plant experiences tissue damage, green leaf volatile chemicals are released. This is easily observed by the “fresh cut grass” smell that follows lawn mowing. But when the saliva of hornworm caterpillars mixes with the green leaf volatiles of Nicotiana, it acts as a chemical beacon calling in the predatory big eyed bug, Geocoris sp. A study in Science journal, submitted by Silke Allmann and Ian T. Baldwin, reported the change in volatile chemical composition, which only occurs with hornworm herbivory, tripled predator foraging efficiency. In addition to the ability to call for help, Nicotiana will also change pollinator strategy when faced with hornworm invasion. Researchers from the Max Planck Institute for Chemical Ecology observed that infested tobacco plants were able to change the time of day at which their flowers opened and also drastically reduce fragrance production. The flowers, now opening at dawn, began to be pollinated by hummingbirds reducing the risk of further hornworm infestation.
In Full Bloom is a weekly feature from Allissa Bunner that focuses on sustainable gardening, environmental stewardship and related community news and initiatives. Bunner is a Norfolk resident who is passionate about plants — especially natives — and enjoys growing things from seed. She admits to a botany bias (blame the biology degree from Old Dominion University) and is working on becoming a well-rounded naturalist as she also teaches her two children to have a love for nature. She can be reached at firstname.lastname@example.org.