Have you ever found a pepper inside a pepper?

When a gardener finds a little pepper inside a bigger pepper, she wonders: Why does that happen and what's it called?

Even the experts can't explain fully why we sometimes find a small pepper inside a larger pepper.

Karan Davis Cutler

April 1, 2010

Gardeners, much like Blanche DuBois in "A Streetcar Named Desire," can count on the kindness of strangers. The strangers in this case were a half-dozen botanists. The kindness was answering a question: What is the term for the small pepper that sometimes grows inside a bell pepper? And what causes it?

I searched the library and the Web before I sought help, so it made me feel better when most of the experts came up empty-handed.

The answer eventually came from John Stommel, a researcher in the Genetic Improvement of Fruits and Vegetables Laboratory of the USDA’s Agricultural Research Service.

Dr. Stommel is located in Beltsville, Md,, the mother ship of the ARS, but the service has units located from coast to coast that carry out thousands of research projects about everything agricultural, both floral and faunal.

Readable summaries of their technical research appear in the monthly Agricultural Research magazine, which you can access online.

Bur back to peppers in peppers. There appears to be nothing published on the subject in the past 50 years other than an article written by three University of California scientists in 1966.

That little pepper inside a bigger pepper is called an “internal proliferation.” Its form can vary from irregular and contorted to a near-perfect but sterile fruit.

A pepper growing inside a pepper is a type of parthenocarpy, which is the formation of fruits without fertilization or the formation of seeds. No one is sure what causes them, but temperature and nutrient levels have been ruled out.

Plant breeders, who consider this anomaly undesirable, keep an eye out for it when selecting for new cultivars, because the trait is inheritable.

So I received no definitive answers about why there are peppers in peppers, but had one definitive discovery: Busy scientists are willing to pause while fine mapping the tomato beta-modifier gene, as Dr. Stommel did, and answer oddball questions from the public.

For the record, an internal proliferation is as edible as its Capsicum container. I think of it as getting a second pepper for free.

Karan Davis Cutler is one of nine garden writers who blog regularly at Diggin’ It. She's a former magazine editor and newspaper columnist and the author of scores of garden articles and more than a dozen books, including “Burpee - The Complete Flower Gardener” and “Herb Gardening for Dummies.” She now struggles to garden in the unyieldingly dense clay of Addison County, Vt., on the shore of Lake Champlain, where she is working on a book about gardening to attract birds and other wildlife.To read more by Karan, click here.

EDITOR'S NOTE: This article has been translated into Estonian. Click here to read it.