This oca is a tuberous root, of an oval shape and pale red colour, but white inside.
"Popular Adventure Tales"
Mayne Reid
In this depression there has existed from old time a kind of suburb or separate district of the poorer people known by the name of the Contrada d' oca.
"Sketches and Studies in Italy and Greece, Vol III."
John Symonds
They were going home in triumph when Rodrigo, young as he was, came up with them in the mountains of oca, and put them all to the rout.
"The Boy's Book of Heroes"
Helena Peake