benzene, luxuriant
苯 centers on a specific chemical compound, benzene, and a separate older sense of lush plant growth. The two meanings do not share one clear conceptual center; the benzene sense is a modern scientific usage, while luxuriant describes thick vegetation.
苯 combines 艹 (grass) with 本 (root/origin). The luxuriant plant sense likely derives from this grass-root combination. The modern chemical meaning 'benzene' is a later borrowing unrelated to the original structure.
Grass 艹 growing thickly from its roots 本 creates a luxuriant, overgrown scene. For the benzene sense, picture a lush field of grass being processed into a chemical compound.
For ホン, imagine a thick, luxuriant hedge of honeysuckle: hone -> ホン, and the lush growth is the kanji's original meaning.
—