Question
Hiya. According to my science teacher, potato is a herb, and not a vegetable. Is this really true? He claimed that the leaves qualified it as a herb, and not as a vegetable, and that the potato itself is just a side-product of the herb.

Odd question maybe, but I hope you know the answer!

Yours sincerely,
Andreas Aguila.

Answer
Interesting question. Actually, per definition, it would be both.
A vegetable is an edible plant, or an edible part of a plant, i.e. the root of a potato plant (a tuber) - a potato, as long as it is cooked. Otherwise potatoes are atually slightly toxic, especially the eyes, which should be removed before cooking. Although I have to admit that my father often ate raw, peeled potatoes and gave them to us as children. My siblings and I are still quite alive and well...
A(n) herb is "a plant valued for flavouring food, for medicinal puropses, or for its fragrance... an annual, biennial, or perennial plant (...) with no persistent, woody parts."* That definition (annual with no woody parts) would also apply to a potato.

While it would botanically qualify as a(n) herb, one has to question what use those leaves might have. Are they fragrant? No. Have they at least medicinal value? Not to my knowledge, nor have I found any indication of such in my textbooks. Do we use them to flavour food? Again, no.

But as a vegetable... Is any part of it edible? The cooked roots are, and how! One of the most versatile and nutritional foods known to man.

Were this person my teacher (someone I am dependent upon for good grades), I would politely agree and yet beg to differ at the same time. Honestly. You can both be right at the same time. Kind of like one person claiming lavender is a flower and one claiming it is a(n) herb. Both are right. Any sensible pedagogue will see the logic in that argument.

Hope that helps you further!
*The New Webster's Dictionary and Thesaurus of the English Language, 1991