Wicked Plants

by Amy Stewart

  RUBBER TREE

  Hevea brasiliensis

  An Amazon jungle native that made its way to Europe courtesy of enterprising British plant explorers. Although uses for the sticky latex were not immediately apparent, chemists working in the 1800s quickly realized that the substance could be used to erase pencil lines, coat clothing to make them waterproof, and—thanks to some experimentation by an American named Goodyear—could even be used to make tires. In the wild the tree has another trick: its ripe fruits explode in the fall with a loud crack, sending cyanide-laden seeds several yards in all directions.

  WITCH HAZEL

  Hamamelis virginiana

  A beloved North American native that produces star-shaped yellow flowers in late autumn. The extract of the bark and leaves is used as an astringent to treat bites and bruises. The branches have been employed as divining rods to find underground sources of water or mines. In the fall, the dry, brown, acornlike seed capsules snap open and throw seeds up to thirty feet away.

  DWARF MISTLETOE

  Arceuthobium spp.

  A relative of the popular Christmastime mistletoe, is a parasite that sucks the life out of conifers in North America and Europe. Its fruit take over a year and a half to ripen, and when they do, the seeds blast off at the astonishing rate of sixty miles per hour—so fast that you might not even be able to see them fly by.

  The rubber tree’s ripe fruits explode in the fall with a loud crack, sending cyanide-laden seeds several yards in all directions.

  DEADLY

  Water Hemlock

  CICUTA SPP.

  Widely regarded as one of the most dangerous plants in the United States, water hemlock flourishes in ditches, swamps, and meadows across the country, and its flat, umbrella-shaped clusters of white flowers and lacy foliage resemble that of its more edible relatives like coriander, parsnips, and carrots. In fact, most accidental poisonings from water hemlock come about because people mistakenly believe the roots are edible. Unfortunately, the roots have a slightly sweet taste that might encourage someone to take a second bite.

  FAMILY:

  Apiaceae

  HABITAT:

  Temperate climates, usually near rivers and wetlands

  NATIVE TO:

  North America

  COMMON NAMES:

  Cowbane, wild carrot, snakeweed, poison parsnip, false parsley, children’s bane, death-of-man

  It only takes a nibble or two to get a lethal dose of the plant’s toxin, cicutoxin. It disrupts the central nervous system, and quickly brings on nausea, vomiting, and seizures. One small bite of the plant’s root, which is its most toxic part, could kill a child.

  In the early 1990s two brothers on a hike mistook the plant for wild ginseng. One man took three bites and was dead within a few hours; the other took only one bite and suffered seizures and delirium but recovered after a trip to the emergency room. In the 1930s a number of children were killed after making whistles or blow darts out of the plant’s hollow stems. Children have also mistaken the roots for carrots and gone into convulsions after a few bites.

  In the 1930s, a number of children were killed after making whistles or blow darts out of the hollow stems of water hemlock.

  There were about a hundred cases of water hemlock fatalities in the United States during the twentieth century, although experts believe the actual number is probably much higher because the victims don’t usually survive to report on what they ate.

  Water hemlock also poses a threat to pets and livestock. Because the plant’s fragrance is not as unpleasant as other poisonous plants, animals are more tempted to graze on it. When mature water hemlock plants are uprooted by tractors, the exposed tap roots can be tempting to hungry animals. Usually the poison works so quickly that animals are near death by the time they’re discovered. A single root is toxic enough to kill a sixteen-hundred-pound cow.

  The weed grows to seven feet tall and sports purple splotches on the stem. The fleshy roots produce copious amounts of the poison in the form of a thick, yellowish liquid that oozes out when the roots are cut. The most widespread species is Cicuta maculata.

  In the western United States and Canada, C. douglasii thrives in pastures and swamps. It produces unusually thick stems and its flowers are so large and sturdy that they are sometimes picked as cut flowers. This is a very dangerous decorating idea; even a small amount of toxic juice on the hands could find its way into the bloodstream.

  Meet the Relatives Poison hemlock, Conium maculatum, which killed Socrates is one relative; others include parsley, carrots, parsnips, and dill.

  DESTRUCTIVE

  Water Hyacinth

  EICHHORNIA CRASSIPES

  This South American native is not hard to recognize. It grows to about three feet tall in water and sports luscious lavender blooms with a distinctive yellow spot on just one of its six petals. Although it is beautiful, the crimes that this aquatic plant has committed are so great that it should be locked away forever—if only that worked.

  FAMILY:

  Pontederiaceae

  HABITAT:

  Tropical and subtropical lakes and rivers

  NATIVE TO:

  South America

  COMMON NAMES:

  Floating water hyacinth, jacinthe d’eau, jacinto de aqua

  Water hyacinth forms dense, sprawling mats on the water’s surface that even commercial boats can’t penetrate. Those mats become islands of their own, providing the perfect environment for other semiaquatic plants and grasses to sprout. It is freakishly prolific, doubling its population every two weeks. While natural predators kept the plant from taking over its native Amazon, it has gone on a crime spree in Asia, Australia, the Americas, and other parts of Africa. The plant is so horrible that it has earned its own Guinness World Record as the world’s worst aquatic weed.

  Its offenses include:

  CHOKING WATERWAYS. The plant will quickly take over a lake, pond, or river, slowing the flow of water, sucking up all the oxygen, and strangling native plants.

  CLOGGING POWER PLANTS. A vigorous infestation of water hyacinth can shut down a hydroelectric power plant or dam, making the lights go out for thousands of unsuspecting homeowners.

  STARVING THE LOCALS. In parts of Africa, fishermen have seen their catches decline by half because of water hyacinth. The people of Papua New Guinea were unable to fish, get to their farms, or go to market because this floating menace stood in their way.

  STEALING WATER. Clean drinking water is actually in short supply in some parts of Africa because the greedy water hyacinth slurps it up.

  STEALING NUTRIENTS. Although water hyacinth has received cautious praise for its ability to absorb pollutants such as heavy metals, its voracious appetite makes it hard for other tiny water-dwelling creatures to get enough to eat. It devours nitrogen, phosphorus, and other critical plant nutrients until there’s nothing left for the others.

  BREEDING NASTY PESTS. Water hyacinth can be a breeding ground for mosquitoes, which are a vector for transmission of malaria and West Nile virus. It also provides food and shelter for a particular species of water snail that, in turn, is a particularly friendly host for a few different species of parasitic flatworms. Those flatworms emerge from their snail hosts and swim around until they find a human to infest. The disease, widespread in developing countries, is called schistosomiasis, or snail fever. The little worms travel freely in the body, laying eggs in the brain, around the spinal column, and on any organ that looks inviting. Over one hundred million people are infected worldwide.

  The people of Papua New Guinea were unable to fish, get to their farms, or go to market because this floating menace—water hyacinth—stood in their way.

  PROVIDING COVER FOR SEA MONSTERS. One report blames water hyacinth for offering convenient hiding places for snakes and crocodiles, giving it an unfair advantage over unsuspecting boaters, bathers, and tourists.

  Scientists are looking at the possibility of introducing insects to eat the wicked weed, but
they fear they might just be introducing another environmental thug into the mix. Stay tuned—and stay away from water hyacinth.

  Meet the Relatives There are seven different species of water hyacinth, most of which are invasive.

  OFFENSIVE

  SOCIAL MISFITS

  The way some plants behave is disgusting and downright embarrassing. There are the arsonists—plants that use fire as a weapon to clear the way for their offspring and kill off their competition. Some even require a good hot fire for their seeds to germinate. Some cities in drought-prone areas even publish lists of flammable plants to avoid.

  Other offenders stink, slobber, and even bleed. Don’t invite any of these horticultural misfits to your next garden party.

  Pyromaniacs

  GAS PLANT OR BURNING BUSH

  Dictamnus albus

  A flowering perennial native to Europe and parts of Africa. On a hot summer night, the plant produces enough volatile oil that lighting a match nearby can set it on fire.

  EUCALYPTUS TREES

  Eucalyptus spp.

  Native to Australia but naturalized in California; the highly volatile oil produced by the trees helped spread the deadly Oakland fire that killed twenty-five people and destroyed thousands of homes.

  PAMPAS GRASS

  Cortaderia selloana

  A South American native that has become a much-hated invasive plant in the western United States. Each clump can reach over ten feet tall and produce so much dry, brittle biomass that it can accelerate and redirect wildfires.

  On a hot summer night, the gas plant produces enough volatile oil that lighting a match nearby can set it on fire.

  CHAMISE

  Adenostoma fasciculatum

  A flowering chaparral shrub that produces a flammable resin; the plant is also rejuvenated by fire and is one of the first plants to sprout out of the blackened earth.

  Stinkers

  CORPSE FLOWER OR TITAN ARUM

  Amorphophallus titanium

  Resembles an enormous burgundy calla lily. It usually goes several years without blooming, but when it does, it produces a single flowering stalk that can reach up to ten feet tall and weigh over a hundred pounds. When a corpse flower blooms in a botanical garden, visitors line up to see it, but they are warned to enter the conservatory carefully as the stink can be overpowering.

  RAFFLESIA

  Rafflesia arnoldii

  Produces the largest single flower in the world at over forty inches across. (The enormous corpse flower is actually a cluster of many small flowers on a stalk, knocking it out of the running.) This squatty, speckled, orange plant parasite is truly a flower that only a botanist could love. The flowers last only a few days and stink of rotting meat while they bloom, attracting flies that feed off dead animals in the Indonesian jungle where it lives.

  The flowers last only a few days and stink of rotting meat while they bloom, attracting flies that feed off dead animals in the Indonesian jungle.

  WHITE PLUMED GREVILLEA

  Grevillea leucopteris

  An Australian plant in the protea family that produces gorgeous stalks of yellowish white blooms. Unfortunately, most people won’t go near it because of the stink, which is reminiscent of smelly old socks.

  STINKING IRIS

  Iris foetidissima

  A lovely English woodland iris whose purple and white blossoms fill the air with the scent of roast beef. Some gardeners believe it more closely resembles burning rubber, garlic, or raw meat gone bad.

  STINKING HELLEBORE

  Helleborus foetidus

  Popular in England for its lime green flowers and dark, dramatic foliage. When crushed, the leaves give off an odor that has been described as “catty” or “skunky” or simply “acrid and unpleasant.”

  SKUNK CABBAGE

  Symplocarpus foetidus

  Grows in wetlands throughout eastern North America and in parts of Asia. Known for its ability to give off heat; in winter, skunk cabbage can break through frozen ground and melt the snow around it, allowing it to bloom and attract pollinators ahead of spring flowers. Crushed skunk cabbage leaves give off an unpleasant scent similar to a skunk’s spray.

  VOODOO LILY

  Dracunculus vulgaris

  Popular among gardeners despite its rotting meat scent. The flowers, which bloom every spring, resemble purplish black calla lilies. The plant grows to three feet tall, making it a striking feature in the garden. Fortunately, the flowers only stink for a few days while they are in full bloom.

  STINKING BENJAMIN

  Trillium erectum

  A lovely red or purple trillium that thrives in moist woodland conditions in eastern North America. This is one of the milder stinking plants—botanists have described it as having a musky scent or smelling like a wet dog.

  Just Disgusting

  SLOBBER WEED

  Pilocarpus pennatifolius

  Actually, you’re the one who will drool. The 1898 King’s American Dispensatory reported on the plant’s powerful effect on the salivary glands, stating that “the secretion of saliva increases to such an extent as to greatly embarrass speech, the person being often obliged to assume an inclined position that the escape of the saliva may be facilitated. During its salivary action one or two pints of saliva, and even more, may be secreted.”

  Don’t try this as a party trick, however. The drooling is often followed by hours of nausea, dizziness, and other unpleasant symptoms. Other plants that make you drool include the betel nut, which produces bright red saliva, as well as the Calabar bean and pencil tree, both of which also bring on unpleasant and sometimes fatal side effects.

  SANGRE DE DRAGO

  Croton lechleri

  A shrub in the Euphoribiaceae family that oozes a thick red sap. The “blood” is used by some Amazon tribes to stop bleeding and treat other medical ailments.

  PTEROCARPUS TREE

  Pterocarpus erinaceus

  Secretes a dark red resin that is used as a dye. The wood can be used to produce fine wood products; its leaves make good feed for cattle; and it may have some medicinal qualities.

  DRACO

  Daemonorops draco

  Grows in southeast Asia; the reddish brown resin it excretes has been collected and sold in small, solid chunks as “red rock opium.” Poison control centers and law enforcement agencies in the United States started seeing the substance on the streets in the late 1990s. However, laboratory tests confirmed that it has no hallucinogenic properties and certainly contains no opium.

  During slobber weed’s salivary action one or two pints of saliva, and even more, may be secreted.

  PAINFUL

  Whistling Thorn Acacia

  ACACIA DREPANOLOBIUM

  One of the most wicked of the hundreds of acacias found throughout the world, this scrubby East African tree employs painful, three-inch thorns to keep browsers away from its lacy leaves. It is also host to a band of aggressive, stinging ants.

  FAMILY:

  Fabaceae or Leguminosae

  HABITAT:

  Dry tropics, Kenya

  NATIVE TO:

  Africa

  COMMON NAME:

  Whistling thorn

  Four different species of ants have taken up residence in these trees, although they can’t occupy the same tree without going to war with each other. They live in the swollen bases of acacia thorns, which they enter by chewing a hole through the thorn. That small hole creates the strange whistling sound that the tree makes in the wind.

  The ants are not only ferocious; they’re organized, too. Small militias patrol the branches looking for predators. They will swarm over a giraffe or other grazing animal to keep it from destroying their home. Other ants selectively prune the tree, allowing new growth only near their colonies so that they can enjoy the tree’s nectar. The ants will also chew climbing vines and other invasive plants down to stumps. If a tree occupied by a rival colony stretches its branches too close, the ants will decimate half of their own tree
to keep the canopies from touching and creating a bridge to enemy territory.

  The little zombies carry the acacia seeds around as if they were their own dead, helping to disperse the seeds and start the next generation.

  And when the tribes do fight, they fight to the death. Researchers once tied the branches of neighboring trees together to provoke a conflict, and the ant corpses were piled a half-inch deep on the ground the next morning.

  Meet the Relatives Some species, including Acacia verticillata, secrete a chemical that induces necrophoresis, or corpse-carrying behavior, in ants. The little zombies carry the acacia seeds around as if they were their own dead, helping to disperse the seeds and start the next generation. Many also have thorns; the cat claw acacia, A. greggii, is sometimes called the wait-a-minute bush because its prickles will grab hold of a hiker and refuse to let go.