What did Lewis and Clark mean by "white apples?"

One of the foods that Sacagawea provided the Corp of Discovery while gathering plant food was a root Lewis and Clark called in their journals, "white apples."

They were referring to the little-known prairie turnip, psoralea esculenta, and it grows mainly in the plains of North America. (See map below.)

Indians and pioneers relied on the prairie turnip in times of famine.

State Historical Society of North Dakota (00086-0391)

Sacagawea dug them out of the ground and ate them raw shortly after she recovered from her illness while on the journey with Lewis and Clark and made herself sick again. 

Here is a picture of roasted prairie turnips. They look delicious.

http://skipthepie.org/ethnic-foods/prairie-turnips-raw-northern-plains-indians/

Usually the turnips are gathered, cleaned and then braided to dry. To rehydrate them they place them in water.

http://learnwithpictures4betterunderstanding.blogspot.com/2009/11/prairie-turnip.html

http://learnwithpictures4betterunderstanding.blogspot.com/2009/11/prairie-turnip.html

Learn more about prairie turnips by clinking on the links below.

http://tangled-me.blogspot.com/2009/06/getting-in-touch-with-my-roots.html

http://en.wikipedia.org/wiki/Psoralea_esculenta

http://www.sd4history.com/unit2/prairie_turnip.htm

http://www.manataka.org/page827.html