kind of legendary tree
莆 refers to a specific kind of legendary or mythical tree. Its meaning is narrow and tied to that single concept.
莆 combines the grass radical 艹 with 甫, which likely contributes a phonetic element. The character is used for a legendary tree name, but the exact historical development is uncertain.
The grass top 艹 suggests a plant, and the bottom 甫 looks like a sturdy trunk with branches. Picture a mythical tree growing from the grass, its shape like 甫.
For フ, imagine a legendary tree that makes a soft 'foo' sound when the wind blows through its leaves: foo -> フ.
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