Taters

Taters are a plant with edible tubers cultivated in many areas of Middle-Earth, from the Shire to even Rohan. It is unknown if the plant was native to middle-earth are was perhaps imported by the númenorean Colonists (like Pipeweed and Athelas.

speculations
As Taters are often translated as "Potatoes" it may be possible that Taters were an early relative of the Potato plant (As Pipeweed was a relative of Nicotiana).However it may be possible that Taters were simply different native tubers (perhaps a remote relative to the earth-bread.