Wild animals tend to avoid poisonous plants. That, says Lisa Murphy V’97, is because they are familiar with their native habitat and instinctively know what’s safe and what isn’t. But Murphy, an associate professor of toxicology based at Penn’s New Bolton Center, says domesticated and companion animals lack that sixth sense. Their owners often lack it, too, and that’s why Murphy is so anxious to raise awareness about toxic plants.
At the New Bolton Center, Murphy is in charge of a small fenced garden designed to teach students about poisonous plants in the most tangible way possible—by growing live specimens. “We debated about the name of the garden,” says Murphy, who also teaches, conducts research and is a consultant at New Bolton, “and decided that Teaching Garden was less off-putting than Poisonous Plant Garden.”
Some of the plants in the garden, like the handsome evergreen yew tree, are “drop-down-dead” poisonous. Others may cause nothing more severe than a temporary bout of malaise. “There’s a wide variety of toxic effects,” says Murphy, “death being the most dramatic. Others include vomiting, diarrhea, kidney problems, reproductive problems, seizures.” Some plants are poisonous only to certain animals. Daylilies, for example, are dangerous mostly to cats, for whom they can cause kidney failure. Lupines cause problems for sheep. Much depends on an animal’s natural curiosity, too. “Goats like getting into things,” says Murphy. If they’ll eat the washing off the line, they’ll also forage plants that can make them ill.
The garden contains some surprises, too, such as a benevolent looking cherry tree. It’s not the fruit that causes problems, says Murphy, it’s the pit, the stem and the branches, which can be sources of cyanide toxicity. Wilted red maples leaves, laying on the ground after a storm, can make horses ill, says Murphy, though the precise chemical that causes the poisoning is still unknown. Similarly, the toxic component in white snakeroot, which passes into the milk of cattle that eat it—and killed Abraham Lincoln’s mother—has yet to be identified. “But from what we do know we can prevent problems,” says Murphy.
Many poisonous plants are “really gorgeous” says Murphy, pointing out a clump of vivid pink azalea, known—along with rhododendron, mountain laurel and Japanese laurel—to cause vomiting, as well as neurological and cardiovascular problems. “Now, with people bringing in exotic, non-native species,” she says, “we need to teach people about the balance between attractive landscaping and safety.”
Murphy is working with the Master Gardeners of Chester County to get the garden ready for the summer season. She also hopes, if enough funding becomes available, to install a pergola and benches to encourage students, faculty and staff to stop awhile, as well as raised beds with annuals and medicinal plants that showcase alternative medicine. “Lots of pharmaceuticals come from poisonous plants,” says Murphy. “Just think of digitalis. That comes from foxgloves.”
If you would like to share your gardening talents to help prepare the New Bolton Teaching Garden for the summer season, or are interested in making a financial contribution, please contact Lisa Murphy at 610-925-6217 or New Bolton Center’s director of development Jane Simone at 610-925-6500.
Originally published on May 12, 2005