[Editor’s note: Easter is the second-biggest holiday for candy sales in the U.S., according to the National Confectioners’ Association, with sales of $2.1 billion in 2012. Each year, candy companies produce 90 million chocolate Easter bunnies.]
Chocolate lovers beware! Witches’ broom disease is your worst enemy. This fungal disease attacks Theobroma cacao, the tree from which chocolate is derived, and it has so altered chocolate production that in a generation no one may remember what chocolate as we knew it once tasted like.
T. cacao grows in the tropical rainforests of South America and West Africa. Here at The New York Botanical Garden, several cacao trees can be found in the Lowland Rain Forest Galleries of the Enid A. Haupt Conservatory, and there are preserved, dried specimens in the William and Lynda Steere Herbarium.
Humans unknowingly set the stage for the spread of Moniliophthora perniciosa, the aggressive fungus responsible for witches’ broom disease. To maximize the supply of cacao beans, which are used to make cocoa powder and chocolate, large monocultures of cacao trees were planted in South and Central America in the early 1900s from a selected handful of seeds, chosen for their delectability. This unintentionally placed the trees in a fragile position, since genetically similar populations are more at risk of succumbing to devastating pathogens. The fungus first appeared in Ecuador in the 1920s and has since spread throughout the Neotropics. Ten years after first being spotted in Bahia, Brazil, nearly 75 percent of the native cacao trees have been eradicated.
With 7.4 million specimens, the William and Lynda Steere Herbarium of The New York Botanical Garden is a repository of thousands of scientifically significant, historic, or interesting plant specimens collected from around the world. Among these are specimens of the plants that are used to make curare, or blow-dart poison, which were collected during an intensive investigation of the poison for medicinal use in the late 1930s. That research was the start in the chain of events that revolutionized medical anesthesia.
Curare is extracted from a mixture of varying botanical sources, including species of the Menispermaceae and Loganiaceae families. Indigenous tribes of the Amazon region and elsewhere around the Neotropics have been credited with formulating curare, which induces muscular paralysis upon entering the bloodstream but is not toxic when ingested, making it ideal for hunting. Peter Martyr d’Anghiera, who chronicled Spain’s discoveries during the Age of Exploration, first described the poison in 1516. In 1595, Sir Walter Raleigh of England met the tribesmen of the Amazon region and returned with preparations of the poisonous herbs known by the natives as “ourari,” which later evolved into “curare.”
Elizabeth Kiernan is a project coordinator for the William and Lynda Steere Herbarium at The New York Botanical Garden. She is currently working on a program to document the biodiversity of the Amazonian region of South America. Each Wednesday throughout Women’s History Month, Science Talk will celebrate one of the many women of science to have left a mark on botanical history.
Jeanne Baret risked everything for her love of botany and, in doing so, became the first woman to circumnavigate the globe. This notable feat was even more remarkable because for much of the voyage, her shipmates did not know she was a woman.
Baret was born in France in 1740. Her working-class parents taught her to identify plants for their healing properties, and she became an expert “herb woman,” a peasant schooled in botanical medicine. Her passion for botany drew her to renowned naturalist Philibert Commerson, who shared her fascination with plants.
Through the recommendation of Carl Linnaeus, the Swedish botanist who devised the system for naming species that science still uses today, Commerson was hired as the botanist on Louis de Bougainville’s voyage around the world in search of undiscovered territories, which set sail in 1766.
Commerson wanted Baret to join him in identifying and collecting plant species because of her vast botanical knowledge, but at this time women were strictly prohibited from sailing aboard French ships. Baret and Commerson devised a plan so that she could join the expedition as Commerson’s field assistant: disguise Jeanne as “Jean” by wrapping bandages around her chest and dressing her in loose-fitting clothing to hide her gender.