From creepy to dangerous, some plants are a perfect Halloween fit

Even plants can get into the spirit of Halloween.

Kyle Martin sees it all the time. He’s a doctoral candidate in plant biology at Cornell University whose specialty is brood-site deception. That’s when a plant masks itself, sending misleading signals to fool a pollinator.

In other words, when you can’t say it with flowers, say it with stench.

“The flowers I study usually smell like rotting substrates, like fruit or carrion, to attract insects,” he says.

It’s a horticultural twist on trick or treat.

“A lot of flowers provide a treat, like a sweet-smelling treat or a nectar reward for the service of pollination,” Martin says. “But all the flowers I study are tricksters. They trick their pollinators and don’t give a treat back.”

For example, Dracula orchids. Native to South America, they tend to be purple or maroon and hairy, Martin says. “They mimic fungal fruiting bodies. They smell like mushrooms or other fruiting fungi. … They attract flies looking for a spot to lay their eggs.”

Once pollination is achieved, the rendezvous is over. The pollinator gets no treat, no sweet nectar as a reward.

Many plants are a nice fit with Halloween — not to put in your yard but rather to shudder at and ogle from afar. Some are scary-looking. Some are ugly. Still others are just, well, ewww.

Here’s a rundown of some of what’s out there:

Scary-looking

Titan arum: Also known as the corpse flower, the titan arum (Amorphophallus titanum) has it all: It’s gigantic (up to 10 feet tall), it grows quickly, and it exudes a foul odor. Martin says it’s the scariest plant he has ever encountered. “Just looking at it; it’s this massive plant, taller than a lot of us. (When it blooms) it smells like rotting meat. When I’m showing the flower to the public, even adults are wary to look into it. They don’t want to touch it.”

Doll’s eyes: How’d you like to be in the woods and find a bush full of these watching you? Doll’s eyes (Actaea pachypoda), also known as white baneberry, is a native plant found in eastern North America. It grows up to 2 feet tall and produces the small, white, poisonous fruit that gives it its name.

Nepenthes rajah: This endangered plant from Borneo boasts traps nearly the size of a football, says Devin Dotson, public affairs and exhibits specialist at the U.S. Botanic Garden in Washington. “The lurid traps entice insects to a watery death, along with the occasional lizard or rat,” Dotson says. Interestingly, the same liquid welcomes an array of creatures resistant to the digestive juices, including mosquito larvae.

Dangerous

Poison ivy: Jacob Burns, curator of herbaceous perennial plants at the Chicago Botanic Garden, says Toxicodendron radicans gets his vote for scariest plant. “Every part of the plant is toxic,” Burns says. “Urushiol is the oil on it. It causes a long-lasting rash on most humans. You don’t even have to touch the plant to get the rash, because that oil is so easy to get on your boots, your dog, the lawn mower. And that oil can remain on items for years.” Because it’s everywhere — dry areas, wet areas, roadsides, riverbanks, woods — it’s easy to come in contact with. Burns recalls the old rhyme “Leaves of three, let it be” to help identify this foliage fiend.

Apples: Well, not what you’ll find in the store today. “The really, really old varieties of apples — I’m talking from 100 years ago — the seeds are laced with cyanide,” says Karl Niklas, the Liberty Hyde Bailey professor in the section of plant biology at Cornell University. “They can kill you. Of course, people don’t eat the core of the apple, but still. (In) the new cultivars, what we find today in grocery stores, that intensity of poison has been bred out.”

Stinging nettle: Found in North and South America, Europe and Asia, the nettles plant (Urtica dioica) has hollow stinging hairs on its leaves and stems. On contact, they inject chemicals that produce a stinging sensation. “Anyone who has walked through a patch of stinging nettles doesn’t do it again,” says Niklas.

Creepy

Bat flower: Niklas has been teaching for 37 years, and when he says something is “really creepy looking,” you listen. This plant is native to Southeast Asia. Its bloom is black — unusual for a flower — and up to a foot across, with “whiskers” as long as 2 feet. And the flower seems to hover almost menacingly above the plant’s green leaves.

Aristolochia: This plant, which has 500 varieties (its members are often called Dutchman’s pipe and pipevine), captures and imprisons pollinators before releasing them. “They tend to be very large, and they have this surface that looks like rotting meat, really,” Martin says. “Once the pollinators are attracted to Aristolochia flowers, by a combination of scent and visual display, they are directed through a tube into the chamber which houses the plant’s reproductive organs. Downward facing hairs line the tube, which prevents the insects from leaving once they have entered the chamber. Any Aristolochia pollen that was on the insect body is passively deposited on the female parts of the flower on the first day while the female parts are receptive. The insect is held captive overnight until the male part of the flower matures and showers pollen on the captured insects. Once this happens, the hairs on the inside of the tube wilt and the insects are released. If the insects are tricked again by another Aristolochia flower, then cross-pollination will occur.”

Ewwww

Prairie dodder: This parasitic vine (Cuscuta) has a “creepy, alien look,” Burns says. Like most other parasitic plants, it doesn’t have foliage. “They don’t need leaves, don’t need chlorophyll, because they’re sucking the life out of other plants. It’s an orange twining vine that lacks leaves, thus needing zero water.” The vine can grow to 7 feet before it strangles and smothers the host plants. It’s also known as devil’s guts, strangleweed and witch’s hair.

Cobra lily: Darlingtonia californica puts up tall green pitchers with hollow, inflated tops, each bearing a striking resemblance to a cobra poised to strike, Dotson says. “A maroon landing pad shaped like a forked tongue completes the picture and offers a place for its insect victims to perch before they fall to their deaths,” he says. The carnivorous plant lives only in the wet meadows of coastal California and Oregon.

Bleeding tooth fungus: The name says it all. The fruit secretes a red liquid that resembles blood. With spikes and a bitter taste that makes it inedible, this fungus (Hydnellum peckii) belongs on any scary plant (or fungus) list. It is found in North America and Europe, though in recent years it has been discovered in Iran and Korea. Its goal is to take over the world.