Crazier things have made it, even made it big, in the American marketplace, but fungal furniture - furniture made from mushroom roots - may be a little too "out there" for most people.

Yet "out there" - in the marketplace - is where Brian McClellan, 23, and Merjan Tara Sisman, 21, aspire to be with the mushroom chair and pendant lights they created for their senior project at Philadelphia University this year.

"I hate mushrooms, sadly. The texture is too funky. But I love their growing capabilities," says McClellan, who graduated in May and is working part time as a bartender while he refines the design of his pendants.

Mycelium, a cobwebby network of microscopic filaments or hyphae, grows underground, absorbing nutrients, decomposing, making soil, and "producing mushrooms in the same way an apple tree makes fruit," says Lauraine Hawkins, an assistant biology professor at Penn State Mont Alto in Franklin County, Pa., who studies fungi.

What about putting that renewable, biodegradable, nontoxic network to entrepreneurial use? "That's interesting," she says.

To put it mildly.

From the get-go, McClellan and Sisman were "blown away by the idea" of designing with a living material, Sisman says in an e-mail from Istanbul, where she is visiting her family before returning to school to finish up some course work.

But which material? It took a month and a half to decide.

The pair checked out British fashion designer Suzanne Lee, who makes cloth out of green tea, yeast, and bacteria. They explored pressed leaves and seaweed at the Material ConneXion library in New York. They considered moss. And they read Mycelium Running: How Mushrooms Can Help Save the World by Paul Stamets.

Mushrooms won the toss. "We finally felt confident we could get the product we wanted," says McClellan, a Marlboro, N.J., native who lives in Port Richmond.

And so the experimentation began.

McClellan and Sisman found a California farm that sells "bricks" of agricultural waste (wood chips, sawdust, and other stuff) inoculated with fast-growing oyster mushrooms. Inside plastic containers and grow bags, the pair broke up the bricks, kept them moist, and molded the concoction into the shapes they needed.

Everything was kept dry and sanitary in a cool, darkened room at school.

The students picked off any mushrooms that sprouted and waited for the mycelium to grow and bind the mixture together. The lights took two weeks, the chair more than three, and surprisingly, there was no 'shroomy odor.

Finally, the shapes were removed from the molds, air-dried, and baked, which stopped the growing process - the lights in a convection oven, the chair in a pizza oven commandeered for the occasion.

McClellan says he chose to design a pendant "knowing for most of its life span it would be out of human contact . . . . That said, it is still very durable. It can be handled and moved around," albeit gently.

Sisman intended her chair for indoor use, but it's not ready to be sat on just yet. "With different organic finishes, it could be durable enough for outdoor use. The fact that it is low-cost, biodegradable, and a low-energy process is very exciting but mostly promising," she says.

And the chair needed no hardware. As Sisman says, "the legs are consumed into the seating surface . . . the mycelium grabs on and grows around it."

Worth repeating: By the time this process is complete, the mycelium is dead. No chance the chair will turn into The Blob, and the light will never rain fungal spores.

"What I loved about mycelium was the fact that its act of growth became the design itself," Sisman says. "It is actually beautiful. It is a pretty little smart thing that holds great potential."

Some have already discovered that.

Philip Ross, a San Francisco artist, has been experimenting with fungi for two decades, making footstools, chairs, and bricks that could be used instead of concrete in construction. Ecovative Design of Green Island, N.Y., founded in 2007, makes mycelium packaging for clients that include Dell, the computer company.

The brainchild of two product design and engineering students at Rensselaer Polytechnic Institute, Ecovative is now developing mycelium furniture, building materials, and automotive products. (Its packaging line will be exhibited at the EastPack trade show at the Convention Center, June 18 to 20.)

"We think the future for mycelium is huge," says marketing director Sam Harrington, a Doylestown native.

Clint Springer, assistant professor of plant biology at St. Joseph's University, sees the possibilities, too. "Knowing what mycelium is made of, it makes you wonder. Why didn't we think of this before?" he says.

Citing the intense interest in sustainability at every level of American society, Springer notes that biological organisms are the epitome of sustainable design. "Industry and other firms are increasingly looking to them for solutions because basically, the engineering is done for you," he says.

McClellan and Sisman continue to reengineer their designs and hope to find a mycelium source in mushroom-rich Kennett Square. Sisman is also thinking of getting a master's degree in architecture and pursuing a career in furniture and store design.

Meanwhile, Götz Unger, director of Philadelphia University's industrial design program, is encouraging them to continue their experiments with form, shape, and material - and, regardless of what happens, to consider the industrial design process its own reward.

"You get to dream stuff up and find a way to make it happen," he says.