The leaves on the stems and branches are arranged in certain patterns. Phyllotaxy is the term for the non-random arrangement of leaves that helps classify and identify plants.
Alternate, whorled, and opposite phyllotaxy are the three forms of phyllotaxy.
Alternate phyllotaxy:
Individual leaves emerge from each node on the plant's stem in alternate phyllotaxy, and they are arranged in a spiral pattern from node to node down the stem.
Sunflowers, china rose, and mustard plants all have this type of phyllotaxy.