The "Sweet Potatoes" performed by the Muldaurs (actually, Maria Muldaur, vocals and Jeff Gutcheon, piano) is a slow, sultry, chromatic, bluesy love song - not one of the ones mentioned above. It begins:

I get by without a try
As long as I have you, dear
Don't know just what I would do
If you were ever gone...

and ends:

I've been stuck on my sweet potatoes
Ever since I learned to see,
And you sure have been a
Good old habit to me.

(This is the only mention of sweet potatoes in the lyrics.)

The album cover lists the performers for each track, but doesn't provide attributions of authorship. I got my copy second-hand, so I'm probably missing liner notes. The album is worth hunting down for this song alone, but it also features great renditions of "Blue Railroad Train", "Havana Moon", "Lazybones", "Cordelia", "Dardanella", "Lover Man" and "Hard Time Killin' Floor". Also a rollicker everyone should get to hear at least once, "Kneein' Me":

You're kneein' me in the balls,
You're ballin' me in the knees,
You're doin', doin' whatever you please!