Dear Thomas,

Every few years, a smell like a rotting corpse wafts around a stairwell at Washington State University Vancouver. But it’s not really a dead body. It’s the bloom of the corpse flower plant.

There are fewer than 1,000 corpse flower plants left in the wild. It’s one of the rarest plants in the world.

But the list of rare plants is massive. If you look at all the plants we know about in the world, there are about 435,000 different kinds of plants—and many more we don’t know about. Some scientists say that more one-third of all plants are “exceedingly rare.”

I asked my friend Dawn Freeman what makes a plant rare. She’s responsible for the WSU corpse flower.

“What makes the corpse flower rare is that it has a very, very small native habitat,” Freeman said. “Its habitat is one side of one mountain range on the island Sumatra in Indonesia.”

That habitat is being destroyed to farm palm oil. Habitat destruction is one reason the corpse flower and other rare plants are in danger of going extinct.

The corpse flower is also rare because it takes so long to bloom. If you dig underneath a corpse flower plant, you’ll find a swollen root kind of like a potato. It’s called a corm. It can weigh up to 200 pounds!

The corm sends up a giant leaf. The leaf uses the sun’s light to make sugar and stores it in the corm. After about a year, the leaf dies, and the plant is dormant for a few months. The plant does this seven to ten times before it has enough energy to make its first bloom. That means it can take 10 years to make one bloom.

The maroon bloom looks like a flower, but it’s really a flower holder. Inside is a tall green spike with yellow flowers and red flowers on it. That spike makes heat and a smell like rotting meat. It’s an enticing smell for flesh flies, carrion beetles and other insects that eat or nest in dead things. They zoom toward the bloom and dive in to look for tasty rotten flesh—but it’s a trick.

As the disappointed flies and beetles climb out, pollen from the yellow flowers sticks to them. If they visit another blooming corpse flower, that pollen will fall off onto the red flowers and make fruit. Then a rhinoceros hornbill bird eats the fruit and poops out the seeds to make baby plants.

“So, it’s rare because its habitat is small and being degraded and because it only opens after 10 years and stays open for just a day or two,” Freeman said. “The fact that this plant persists at all in the wild is amazing.”

The corpse flower and many other rare plants are on the Red List of Threatened Species compiled by the International Union for the Conservation of Nature. You can use their database to investigate nearly 25,000 plants that are critically endangered, endangered or vulnerable. That means they’re at risk of becoming extinct unless we do something to protect them and their homes.

If you find one rarer—or more stinky—than the corpse flower, I’d love to hear about it.


Dr. Universe

P.S. Want to know what endangered plant matches your vibe?