The word "梧桐" is formed by combining two phono-semantic characters: "梧" integrates the semantic radical "木" (tree) with the phonetic component "吾" (wú) for pronunciation, and "桐" similarly uses "木" for meaning with "同" (tóng) for sound; together they create a compound word specifically denoting the phoenix tree, where the repeated "木" radical reinforces its botanical nature.