The Master Gardener’s Bookshelf
50 Plants that Changed the World by Stephen A. Harris
Review by Sandy K. Johnson, Extension Master Gardener
A new book, 50 Plants that Changed the World, is a fascinating look at the history of plants critical to the development of civilization.
Of the 35,000 (at least!) plant species across the world, author Stephen A. Harris identifies 50 that he deems crucial to the evolution of the Western world. He then explores them through trade, imperialism, politics, medicine, travel, and chemistry.
“The discovery of crop origins is more than an intellectual exercise,” Harris writes. “As we begin to understand how crops evolved, we can increase the precision with which we are able to breed and improve them. These skills will be essential if 9.7 billion people are to be fed by 2050.”
He describes foods that built empires: rice from China, sugarcane and bananas from South Asia, maize from Mexico, and potatoes from the Andes. As explorers ventured across the globe, new territories were conquered—and new plants “discovered” and transported to their home base. People became rich trafficking newly discovered plants, and popular crazes erupted over plants like pepper, nutmeg, and tea.
To help explain his 50 choices—which he admits is a highly personal selection—Harris utilizes a chronological approach defined by when they first became influential in Western civilization.
His first entry is Hordeum vulgare (barley), first domesticated up to 8,000 years ago in the Fertile Crescent, which extends from modern-day Syria to Iran. Barley is primarily associated with making bread, beer, and spirits, and even though its popularity was subsequently eclipsed by wheat, more than 150 million tons of barley are still produced each year.
I won’t attempt to detail each of Harris’s 50 choices but will instead focus on a few that are dear to Extension Master Gardeners.
Beta vulgaris (beet). The beet in its earliest form dates back 8,000 years in the Near East and was at first favored for its leaves. Europeans cultivated the swollen underground beetroot, which Harris says was initially called the whimsical “fodder mangelwurzel.” The sugar beet turned the vegetable from a garden staple to an industrial crop, especially after an early chemist demonstrated that sucrose in beets was the same as cane sugar. In an example of the global politics of a plant, Napoleon ordered French farmers to plant sugar beets and banned the import of sugarcane from the Caribbean.
Brassica oleracea (brassicas). This family is one of the most diverse, Harris writes, and includes cabbages, kale, broccoli, cauliflower, kohlrabi, turnips, Brussels sprouts, horseradish, arugula, and mustard. Brassicas evolved pungent oils as a way to defend against insects, and they were weaponized a century ago as mustard gas. Harris argues that generations of evolutions of the brassicas make them an ideal food to adapt with climate change.
The Farmstrs via Wikimedia Commons
Allium (onions). Onions and their cousins—leeks, garlic, and chives—date to Mesopotamia 6 millennia ago, where instructions for cultivation and use were painstakingly baked into bricks. Harris says Near Eastern superstition claims that onion and garlic sprang from Satan’s right and left footprints in the Garden of Eden. The unmistakable flavor and smell of alliums are essential to many cuisines, resulting in the annual production of 115 million tons of onion and 29 million tons of garlic.
Solanum lycopersicum (tomato). Harris says the first domestication of tomatoes occurred in Ecuador and Peru, morphing a tiny weedy fruit into today’s hardy plant that can bear individual fruits as big as a softball. Spanish conquerors brought tomato seeds to Europe centuries later where the red fruit earned its “love apple” nickname.
50 Plants that Changed the World (University of Chicago Press, 2025) is richly illustrated with 55 historical color sketches, most from the 1700s, a few even older. It is available at the Arlington Public Library.
Harris is the Druce curator of the Oxford University Herbaria and a researcher who concentrates on the use of molecular markers in evolutionary and conservation biology.