Shepherd's purse is common and very nutritious. (Barbara Damrosch/BARBARA DAMROSCH)

They’re called poor people’s foods. Plants foraged by starving folk and scavenged when crops succumb to drought: They’re what you eat just to get by. Many are unusually rich in nutrients, have medicinal value and may even taste good. But because they’re free for the taking they get little respect.

Scientists in fields such as ethnobotany study them and the ways they are eaten. But the true experts are indigenous people all over the world who’ve inherited them as part of their culture.

To the rest of us, who rely for our food on an alarmingly few species of plants grown on an industrial scale, these wild edibles are a gardener’s curiosity that may hold the key to a more sustainable way of feeding the world in the years to come.

A treasure house of knowledge about survival plants can be found on the Famine Foods Web site , sponsored by the horticulture department of Purdue University. Browsing through its database, you might be surprised to see a number of foods that are in your yard, such as the leaves of forsythia — eaten in China with oil and salt — or a garden narcissus that the French turn into flour. Will times ever be so bad that you’ll need to nibble the edible leaves of your expensive Japanese maple? Unlikely. But it’s useful to know that a pesky species like shepherd’s purse, a common weed, is a nutritional powerhouse, and that roots from the evil, tree-smothering kudzu vine, steamed and eaten, could someday save your life.

For the most part, though, these names are mysterious and surprising in their numbers. There are well over 1,000 listed, and many more could be discovered by searching beyond the world’s standard fare. It seems that all parts of a plant are tried — leaves, stems, root, seeds, bark — until someone who is as indomitable as the plant itself finds a way to consume it.

In one entry after another, these foods are made tastier by the addition of salt, oils, chile peppers and other condiments. At times they’re blended with staples such as common flours to stretch the supply. Some must be repeatedly soaked and drained, or boiled, to reduce bitterness.

Even more important are the tricks to reduce the toxicity that some foods possess, knowledge that’s in danger of being lost as these plants lose their habitats or fall further into obscurity. As the world’s population expands, we’ll need crops that grow when nothing else will.

Robert L. Freedman, who created and compiled the database and whose “Notes on the Famine Foods Website” gives a fine account of the subject, writes that there is no time to be lost in studying and rescuing both the plants and their lore. “Among these, known famine plant species may provide alternatives to costly Green Revolution approaches to providing staple crops for areas of the world in greatest need of food production self-sufficiency.”

And who knows which among them might someday be culinary darlings? I recall a native poverty food of ours, the eating of which was once so shameful that its remains were quickly buried. It was called the lobster.

Damrosch is a freelance writer and the author of “The Garden Primer.”

Tip of the week

Provide a decorative and useful edge to the vegetable garden with a row of okra plants. Sow seeds now and thin after germination so plants are spaced 18 inches apart. Plants can grow as high as seven feet, depending on variety. Soak seeds overnight before planting to speed germination. Apart from local garden centers, a good source of okra seeds is Southern Exposure Seed Exchange (540-894-9480,

— Adrian Higgins