As mentioned here is the pdf on the history of botanical illustration. The idea is that it will get you interested and you will perhaps research further.
“The ancient Chinese, Indians, Egyptians, Babylonians, and Native Americans were all herbalists. The oldest known list of medicinal herbs is Shen Nung’s Pen Ts’ao or Shennong Ben Cao Jing (c. 3000 B.C.), a Chinese herbal that is probably a compilation of an even older oral tradition.”
University of Virginia