I cooked parsnips for the first time this week (glad I did - delicious). When the produce clerk pointed them out, I asked if he had baby parsnips instead (as the recipe called for them).
He pointed out parsley root, which looked very similar. I did a search while in the store (and got in many shoppers' way), but could not find whether they were the same thing definitively.
A follow up question would be, if they aren't in fact the same thing, had I chosen to make this dish (roast veggies and chicken), how would the taste have differed for the parsley roots?