Plants have killed plenty of people. When plants are implicated in the death of a human, we typically think of plant poisonings. Rightly so since their are a slew of poisonous plants with the potential to kill. However, oftentimes plants kill (or seriously injure) people without employing toxic substances. One of the best examples of this is falling plant parts. Gravity couples with sheer coincidence and/or human error, and tragedy ensues. In an episode entitled Killer Plants of the now defunct podcast, Caustic Soda, the hosts present some of these distressing scenarios. What follows is a summary of the plants that made their list.

Branches falling from trees, whether dead or alive, can cause some serious damage. Trees in the genus Eucalyptus, commonly known as gum trees, are one group to be particularly wary of. There are more than 700 species of Eucalyptus, most of which occur in Australia. Not all are large trees, but those that are can be massive, reaching from 100 to 200 feet and taller. Eucalyptus trees regularly shed branches, often unexpectedly, leading to serious injury or death to anyone who may find themselves on the ground below. Shedding branches is likely a strategy for conserving water during hot, dry summers, and it is common enough that Australian parks departments issue safety advisories to avoid parking or camping below the trees. Even arborists don’t take their chances with these unpredictable trees.

River red gum (Eucalyptus camaldulensis) – photo credit: wikimedia commons

Of course, eucalyptus trees are not the only trees that drop their branches without warning. A falling branch in Yosemite National Park claimed two victims last summer, for example; and falling branches have claimed the lives of a great deal of forest workers, wildland firefighters, and other forest visitors. This happens frequently enough that the branches in question have been given the ominous name widowmakers, and the U.S. Department of Labor lists them as one of many “potential hazards” in the logging industry. What are the chances of being killed by a falling tree? The Ranger’s Blog set out to answer that question and, to set your mind at ease, determined that the chances are pretty slim.

What about other falling plants? Saguaro cactus, for example. Carnegiea gigantea is a tree-like, columnar cactus native to the Sonoran Desert. It is a very slow growing and long-lived species that generally reaches around 40 feet tall but can potentially grow much taller. Saguaros are considered tree-like for their tall stature and branching habit, although not all saguaros develop branches. Some saguaro branches (or “arms”) can be quite large and considerably heavy. In 1982, an Arizona man discovered this when he and a friend were out shooting saguaros. Stupidly, the man repeatedly shot at the arm of an enormous cactus. Ultimately the arm split off and landed on the man, crushing him to death. Of course, saguaros don’t have to be shot at to fall on you. Another Arizona man was fixing a water leak in a Yuma subdivision when a sixteen foot tall saguaro toppled over on him. The man was crushed but lived to tell about it.

Saguaro cactus (Carnegiea gigantea) – photo credit: wikimedia commons

Palm trees drop things on people, too. One tragic example involves a man in Los Angeles standing below a Canary Island date palm (Phoenix canariensis) waiting for a ride to a funeral. The 2000 pound crown of the palm tree split and fell, pinning the man to the ground. Bystanders were unable to remove the crown, and the man died.

The coconut palm (Cocos nucifera) has an additional deadly weapon – its fruit. While the number of deaths by coconut are often exaggerated, they do occasionally occur. Injuries by coconut are more frequent, so precaution around the trees should be taken. After all, coconut palms can reach heights of 80 feet or more, and mature coconuts can weigh more than three pounds (considerably more when they are wet). A falling coconut is something to be mindful of, an observation that led Dr. Peter Barss to study coconut related injuries in Papa New Guinea over a period of 4 years. His research was published in 1984 in the Journal of Trauma and was later taken out of context and used to make the claim that coconuts kill significantly more people per year than sharks. Publicity spawned by this urban myth helped Barss earn an Ig Noble Prize in 2001. Concerns about coconut related injuries also led officials in India to order the removal of coconut palms around the Gandhi Museum in preparations for President Barack Obama’s 2010 visit.

Back in Australia, the towering bunya pine (Araucaria bidwillii) has its equivalent to the coconut in its massive cone. Measuring around a foot long and weighing in at 20+ pounds, these cones make living near bunya pines an act that is “not for the faint hearted.” When the cones are falling, they warrant warnings from the Australian government to keep away from these 90 foot tall trees. This harrowing feature puts bunya pines on a list of infamous plants in Australia with the potential to kill.

Seed cone of bunya pine (Araucaria bidwillii) – photo credit: www.eol.org