When Shakespeare wrote his famous line "That which we call a rose/By any other name would smell as sweet/," roses were one of the most popular nose-pleasing flowers around.

However, this was 1595, long before commercial growing and genetic experimentation shaped the ornamental flower industry into an estimated 18,000-rose variety, thirty-billion dollar industry. In 1595, each rose likely did smell as sweet as the next, but now, fans of the mantra "stop and smell the roses" won't find much to smell. Roses are literally losing their scent.

Rose breeders want colorful, long living, disease-resistant flowers, so fragrance is often a disregarded trait, because odor is genetically tough to manipulate. All roses contain the chemical 2-phenylethanol, but an aromatic cocktail with 50-100 unique chemicals individualizes each rose variety. Since good-looking, long-lasting flowers trump smelly ones, many new varieties are strictly eye candy.

Today laboratories are beginning to identify the compounds involved in scent production and considering ways to restore these lost smells to favorite flowers. Ideally, our noses won't be the sole benefactors. It's possible that through scent engineering, growers will be able to choose and control which pollinators or pests are attracted to each plant, which could reduce the need for chemical pesticides.

Floral-fragrance biochemistry won't happen overnight, though, the chemical choreography of scent production is simply too complex. Scientists are only now beginning to identify the genes, corresponding enzymes, and chemical reactions that create a flower's unique scent. Rest assured, potential new flower scents and the possible re-emergence of old ones will titillate your nose for years.