This paper reviews detailed methods and approaches in relation to the complex machine learning system of automatic ramification (branching) pattern extraction. First, we will introduce plant topological and geometrical description, encode database or structure used for storage of measured plant structure. And then, the most important part of this paper, we will discuss recent methods and theories used for plant topology and geometry acquisition, statistical and structural analysis as well as branching rule extraction for any species of plant. Finally, some unsolved problems and challenges need to be addressed in future research are outlined.

Key words: Pattern extraction, automatic approaches, plant ramification, machine learning, artificial intelligence.