Knowing the history of the plant helps me connect to it and the people who saved its seed.

Thanks!

There are numerous resources, both modern and old. For instance, among the modern references are Will Weaver's books ("Heirloom Vegetable Gardening" and "100 Vegetables and Where The Came From").

Somewhat older are the "X of New York" volumes, such as "Beans of NY," "Apples of NY," etc.

Reaching way back, we have volumes such as Fearing Burr's "Field & Garden Vegetables of America," first published in 1863. And "Thomas Jefferson's Garden Book" And a whole host of others.

Older agriculural reports, such as the USDA's "Yearbook of Agriculture" often provide insights.

Old seed catalogs are a never ending resource. Unfortunately, they are a big-time collector item, and are sometimes cost prohibative.

Understanding human population dynamics is often an important part of the equation. Without knowing something about that, for instance, there is no way to understand the widespread incidence of bi-color tomatoes in eastern Kentucky.

Don't discount anecdotal evidence. Often it provides the only clues to origination. For example, everything we know about the origins of Cherokee Purple tomatoes is anecdotal in nature until Craig LeHoullier obtained and named it.

Now, a partial answer to your specific question. Deer Tongue lettuce, which dates to at least the 1740s, is also known as "Matchless." The Amish Deer Tongue is a later variety, said to be less prone to bolting. I don't know when it was introduced under that name. There is also a Red Deer Tongue.

That information was obtained in only a couple of minutes from references on hand, most of which were named above.