Wicked Plants (22 page)

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.

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.

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:

C
HOKING 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.

C
LOGGING 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.

S
TARVING 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.

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

S
TEALING 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.

B
REEDING 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.

P
ROVIDING 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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.”

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.

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.

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.