What's A Mandrake?

There are plants mentioned in the Bible, whether in the original Hebrew, or translated into Engish, which aren't familiar.

Yesterday, when I was in Tel Shiloh for Rosh Chodesh Prayers, a neigbor with lots more horiticulture knowledge than I have, suddenly pointed down and said:

"Here are duda'im, mandrakes."

I took a good look via my camera's viewfinder. These are the plants Rachel and Leah believed would make them more fertile.