In 1959, chemist Puzant Torigian was challenged by a colleague to make a nicotine-free cigarette. He became somewhat obsessed by the idea and began systematically testing tobacco substitutes, including kale, grape, cabbage, kohlrabi, spinach, carrot, peanut, tomato leaves, and sugar beet tops. Finally, he determined that the best substitute was Lactuca sativus (or lettuce). When its leaves were properly cured, they burned like tobacco, but had no nicotine, were nonalkaloidal, nontoxic, and had lower tar and ammonia residues than tobacco.
Torigian got together a group of investors in his hometown of Hereford, Texas, and in 1965 they introduced Bravo Smokes, the lettuce cigarette.
St. Louis Post-Dispatch - Oct 4, 1966
Reviews of Bravo Smokes were, in general, not favorable. People said that, "It's like smoking old socks." And that they were "worse than dried buggy whip or coffee grounds in a newspaper wrapper."
The company's director of marketing acknowledged that many found the cigarettes disagreeable at first, but insisted that, "If a person will smoke a carton of these he won't be able to tell the difference."
Nevertheless, the company managed to find a small, niche market selling to smokers trying to quit who wanted something that would replicate the ritual of smoking but without the nicotine.
But finally, in 1972, Bravo Smokes went out of business. Torigian attributed this to a fallout among the business partners — not lack of demand for the product.
Dr. Puzant Torigian - via web archive of bravosmokes.com
In the late 1990s, Torigian relaunched Bravo Smokes, and in its new incarnation the company seems to have lasted for at least a decade, selling a "Smoker's Survival Kit," which was 18 packs of Bravos for $92.50. So about $5.14 a pack. However, I'm assuming that the company must eventually have, once again, gone out of business, because I can't find any evidence that it still exists. Its website, bravosmokes.com, has now been replaced by someone's Hebrew-language blog.
Detroit Free Press - May 15, 1966