autumn foliage, birch, maple, (kokuji)
椛 centers on trees with striking seasonal foliage, especially birch and maple, which are known for their autumn colors. The meaning extends to the colorful leaves themselves.
椛 is a Japanese kokuji (国字) created by combining 木 (tree) and 花 (flower/blossom) to represent trees known for their beautiful foliage, such as birch and maple. It does not have a Chinese origin.
A tree 木 with flowers 花, but here the 'flowers' are the brilliant autumn leaves of birch and maple trees.
For かば, imagine a birch tree with bark peeling like a caba (a made-up word that sounds like かば). The caba tree's colorful leaves make it easy to remember.
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