edible mushrooms
藦 refers specifically to edible mushrooms, a type of fungus used as food.
藦 is a phono-semantic compound: the grass radical 艹 indicates a plant or fungus, while 摩 likely provides the sound. The exact historical development is uncertain.
Under the grass 艹, the complex shape 摩 looks like a dense cluster of mushrooms growing in a shaded, sheltered spot.
For バ, imagine a basket of edible mushrooms at a bazaar: bazaar -> バ, and the mushrooms are the star of the stall.
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