In 1999, after being disappointed by the poor selection of plants sold at the big garden centers in the United Kingdom, Diane Halligan created The Weird and Wonderful Plant Company in East Lothian, Scotland, to source, produce, and promote plants that are different than the ordinary. She reports solid business.

"Any keen gardener with a bit of rebel in them-including me-is driven mad by the rows upon rows of pastel colored bedding plants offered by garden centers and some nurseries," she said. "In today's society when land is at such a premium, gardeners want to grow something a bit more special in their borders."

Marty Harper, co-owner of the Weird Dude's Plant Zoo in Staunton, Virginia, also reports robust business. He started his company in 1998 to fill a growing niche in the unusual. Many of his clients are recently retired baby boomers who have given up their fancy threads and skyscraper offices for gloves, a trowel, and a garden in the country.

"Some are retired CEOs trying to wind down and enjoy life," he said. "They can afford to spend $50 to $100 on plants."

Weirdness in plants is relative, explained Harper. For people in the United States, the weirdest plants are ones that grow in faraway places like the island of Madagascar off the east coast of Africa, or China's Yunnan Province. As a result, they cost more than the roses and petunias found at big-box home improvement stores.

Strange Plants

Harper said the largest collection of weird plants is found in Madagascar, where plants have evolved for millions of years in isolation from the rest of the world. Succulent palms from the island belonging to the Apocynaceae family are becoming popular with gardeners in hot and dry climates like Arizona.

Borneo, an isolated island in the South Pacific Ocean, is another place to find a collection of strange plants. The weirdest plant Harper has come across there is Raffelesia arnoldii.

"It is a parasitic plant that has the world's largest bloom, over three feet (one meter) across, has a fleshy spotted color, it smells bad, and has a hole in the center that holds six or seven quarts (about six liters) of water," he said.

The parasite has no leaves, stems, or roots. Rather it lives on the Cissus angustifolia vine, a member of the grape family that grows only in primary rain forest. The blossom is pollinated by flies that are attracted by its offensive smell: rotting flesh.

Other plants that smell like rotting flesh to attract pollinators include the Dragon Arum (Dracunculus vulgaris), which has a burgundy leaf-like flower out of which flows a slender, black appendage. The plant is found in the Mediterranean.

"A related plant is the infamous Amorphophalus whose name relates to the rather suggestive shape of the erect black spadix-literally shapeless penis," said Halligan. "However, all these plants which we consider freaks are only freaks because we cannot see any attraction to carrion ourselves."

Douglas Justice, the associate director and curator of collections at the University of British Columbia Botanical Garden and Centre for Plant Research in Vancouver, Canada, said he is not sure what motivates people to grow plants that smell bad. He prefers the ones that smell good.

"These generally make people smile, particularly when they're surprised by the source, the specific aroma, or its power," he said.

Among Justice's favorite smelling plants include the sweet-smelling leaf undersides of the rhododendrons Rhododendron traillianum and Rhododendron wasonii. He also likes the smell of white chocolate from the small Chilean tree Azra microphylla.

Halligan said her personal favorite weird plants are those with black flowers, such as the black hollyhock (Alcea rosea,) which has double blooms of deep maroon-black on tall stems.

"[Black flowers] seem to rebel against nature and draw us to their nonconformity," she said. "In this respect they are perhaps the rock stars of the plant world."

Weird DNA?

According to Harper, plants evolve their seemingly strange shapes, sizes, smells, and actions for one simple reason: procreation. "Competition is stiff among plants. Everyone is trying to get a piece of the pie," he said.

Justice is less certain as to why plants, including the weird ones, look the way they do, but he likes to speculate. One of his favorite weirdoes is the fierce Spaniard (Aciphylla horrida), which is a member of the carrot family and can be found in New Zealand.

"[It] has leaves shaped like long swords-very stiff and extremely sharp. This is pretty cool in itself, but the flowers are surrounded by similarly ferocious bracts," he said. "Obviously this is a defense against grazing animals picking off the tender bits of the plant, but considering that there are no native grazers, the defense probably evolved to protect the flowers from birds, probably really big birds, like the moa (Dinornithidae)."

Another favorite curiosity for Justice is Harpochloa falx, a small southern Africa grass species that looks like nothing special until one gets up close and realizes it has a chain of upside-down flowers growing off the tips. Most grasses are wind pollinated plants, but Justice speculates that Harpochloa might be adapted to brushing pollen onto passing animals.