The words plantar, planter sound the same but have different meanings and spellings. Why do plantar, planter sound the same even though they are completely different words?
The answer is simple: plantar, planter are homophones of the English language.
Of, relating to, or occurring on the sole of the foot: plantar warts.
One who plants.
A machine or tool for planting seeds.
The owner or manager of a plantation: cotton and rice planters.
An early settler or colonist.
Definitions from The American Heritage® Dictionary of the English Language, 4th Edition and Wordnik.
Homophones (literally "same sound") are usually defined as words that share the same pronunciation, regardless of how they are spelled.