The world is in danger of losing the Sun Crest peach. Extravagantly juicy with a nectar that perfectly balances acids and sugars, it boasts a yellow skin with an amber glow. But because it is soft and easily bruised, it is unattractive to supermarkets, which prefer hearty produce bred to travel well and languish indefinitely. Grown in California's San Joaquin Valley, the Sun Crest is picked only in midsummer and sold primarily at roadside stands.
A similar fate awaits the Limbertwig apple, the red abalone and the Southern field pea, but their plight, happily, has not gone unnoticed. They are among...