These sunflowers in San Diego National Wildlife Refuge are wild relatives of sunflowers that farmers around the world grow to produce oil. Lisa Cox/USFWS

Thanks to National Public Radio (USA) for this summary of a recent scientific study:

Distant Cousins Of Food Crops Deserve Respect And Protection

Hundreds of native North American plants, often dismissed as weeds, deserve a lot more respect, according to a new study. These plants, distant cousins of foods like cranberries and pumpkins, actually represent a botanical treasure now facing increased threat from climate change, habitat loss and invasive species.

The crops that the human race now depends on, including grains like wheat and tree fruit like peaches, originally were selected or bred from plants that grew wild hundreds or thousands of years ago. And those ancestral plants, like the small wild sunflowers that can be found across the United States, still exist. “If you see them growing along roadsides, those are the ancestors,” says Colin Khoury, a research scientist at the International Center for Tropical Agriculture.

In the U.S., there are wild ancestors of blueberries, sweet potatoes, onions, potatoes, and many other food crops. Some of them are quite common. Khoury says wild lettuce plants grow along sidewalks, or in backyards, but go unrecognized. “They look nothing like lettuce,” he says. “They’re scratchy and thorny and little and ugly.”

Other crop relatives are rare and threatened. One of Khoury’s favorites is called the paradoxical sunflower. It “grows just in wetlands of the deserts of New Mexico and Texas. Little salty seeps where there’s a little bit of water beneath the soil,” he says.

Khoury loves these wild relatives of food crops, and not just for sentimental reasons. “These wild plants are valuable,” he says.

That paradoxical sunflower, for instance, can survive in a salty environment that would kill most plants. So plant breeders cross-pollinated it with commercial sunflowers and created new varieties that can grow in places where the soil contains more salt…

Read the whole story here.