Much as so-called eco-designers trumpet them, plant-based alternatives to cotton are a minuscule piece of the fashion puzzle.

Dwarfed by cotton and synthetics such as polyester, spandex and rayon, textiles made from flax, wood pulp, hemp and bamboo make up less than 2 percent of the market. But that percentage is growing because of consumer and corporate demand as well as technological advancements that make natural fibers easier to transform into wearable fabrics.

One of the more promising developments in sustainable textiles is flax, a stalky and fibrous plant that can be grown with far less water and fewer pesticides than cotton and produced at a lower price.

While cotton is cultivated on 12.6 million U.S. acres, flax is grown on only 2 million acres of U.S. and Canadian farmland. Most flax is produced for its grain, which is turned into food.

But its fiber can be transformed into materials that look and feel similar to cotton. As a textile, it's most commonly used in linen in the U.S.

Vancouver, British Columbia-based Naturally Advanced Technologies, in collaboration with the National Research Council of Canada, created a version of flax fabric, Crailar flax. In the works for almost four years, it isn't yet commercially available.

Hanes, in North Carolina, has been working with the Technologies group for more than three years. The company might introduce some products incorporating flax late this year "on a pretty small scale," a spokesman said.

A Naturally Advanced Technologies spokesman said Crailar flax is produced with a naturally occurring proprietary enzyme that transforms fibers from the flax plant stalk into a soft yet strong textile suited for knit garments.

Processing agents for Crailar flax meet Global Organic Textile Standards, according to chief executive Kenneth Barker.

Bamboo, once the darling of eco-designers who prized its silky feel and drape, largely has been discredited as an alternative source. While bamboo grows without irrigation, processing its fiber into textiles requires chemical solvents that can harm human health and the environment.

Hemp, an industrial, nonpsychoactive plant that is part of the cannabis family, has been growing in popularity among clothing makers.

Stella McCartney, Calvin Klein and others use the fiber, which, like bamboo and flax, requires far less water and fewer pesticides to grow than cotton. Because hemp is not legal to grow in the U.S., American clothing designers import most materials from China. As a result, few U.S. garments incorporate hemp.

Tencel, a textile made from the pulp of eucalyptus trees imported mostly from South Africa, is rising in popularity because of its rayonlike feel and sustainable origins. It requires fewer pesticides and far less acreage and water to grow than cotton.

Tencel is the brand name for lyocell, a fabric made from wood pulp. The pulp may be a mix of hardwood trees, although Tencel-branded lyocell is made from eucalyptus.

Patagonia, Banana Republic and L.L.Bean are among the manufacturers that use Tencel.