花瓣
huā bàn · HSK 7
petal
🌸 花瓣 = 花 flower + 瓣 segment/clove; the flower's segments are its petals
瓣 is the same word used for a clove of garlic or a segment of an orange, the natural divisions of a whole. Attach it to 花 (flower) and you get the flower's divisions: petals.
花 — grass radical 艹 + 化 (change/phonetic)
花 is a semantic-phonetic compound. The top 艹 (grass) signals the plant meaning, while 化 ('change, transform') gives the sound and hints at how buds change into blossoms. It originally meant 'flower' or 'blossom' and later extended to 'flowery, patterned, to spend.'