[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.]
Moniliophthora perniciosa mushrooms on a cacao pod. (Photo: Google Images)
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.
Ynes Mexia, a Mexican-American botanical collector and explorer who began her career in 1925, became the most accomplished female botanical collector of her time both in terms of the number of plant specimens she collected and the miles she traveled on her expeditions. Although she began in her mid-50s and her career was relatively short, she was able to collect an incredible 145,000 specimens. Of those, 500 were new species, and 50 were named in her honor. The William and Lynda Steere Herbarium is fortunate to have many of her specimens.
Mexia was born on May 24, 1870, in Washington, D.C. There are varying accounts of Mexia’s early life, but it is agreed that it was somewhat tumultuous. When she was very young, her parents divorced. Her father returned to his native Mexico, and her mother moved the family to Texas. She was married twice: her first marriage ended abruptly with her husband’s death, and her second marriage ended in divorce. After her divorce, she moved from Mexico City to San Francisco and became involved in social work. She also became an active member of the Sierra Club, which motivated her to attend the University of California, Berkeley.
Her interest in botanical collecting began in 1922 when she joined an expedition led by E. L. Furlong, a Berkeley paleontologist. She enrolled in a course on flowering plants at the Hopkins Marine Station in Pacific Grove, California, and soon after embarked on her first botanical exploration trip to Mexico with Stanford botanist Roxana Ferris. Once in Mexico, Mexia decided that she could accomplish more on her own and abandoned the group, traveling the country for two years and collecting more than 1,500 specimens. She made three additional expeditions to Mexico and collected throughout South America in remote areas of Argentina, Brazil, Bolivia, Ecuador, and Peru. She also collected in Alaska and other areas of the United States.
One of the highlights of her explorations was canoeing the Amazon River from its delta to its source in the Andes, covering nearly 3,000 miles in two and a half years. Her specimens were widely distributed to herbaria throughout the U.S. and Western Europe. In addition to collecting, Mexia wrote articles and gave lectures describing her adventures and travels. She died of lung cancer in 1938.
Credit is due to Nina Floy Bracelin, affectionately known as Bracie, who prepared Mexia’s specimens for herbaria. She worked diligently to label the specimens, sending sets to specialists so their species could be determined and distributing the duplicates. Mexia was said to be more interested in exploration and discovery rather than preparing her specimens, but her legacy lives on through those preserved botanical collections, including those that can be found today in the Steere Herbarium.
This specimen of Saurauia mexiae in the Steere Herbarium was collected by Mexia and named in her honor. It is a “type specimen,” which is a specimen selected to serve as a reference point when a plant species is first named.
A curare specimen originally collected by Richard C. Gill
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.
An engraving of Jeanne Baret portrays her in loose-fitting clothing. (Credit: Leemage/Getty Images/Universal Images Gr.)
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.
