species of fragrant orchid
蕙 refers to a specific type of fragrant orchid, valued for its scent. The meaning is narrow and botanical, without broader abstract extensions.
蕙 combines the plant radical 艹 with 惠, which likely contributes the sound and possibly the idea of grace or benefit, fitting a prized fragrant orchid. The exact historical development is uncertain.
The grass top 艹 sits over 惠, which suggests something beneficial or graceful. Picture a graceful, fragrant orchid growing among common grass, its scent a hidden benefit.
For ケイ, imagine a fragrant orchid named Kay, blooming in a quiet garden: Kay -> ケイ, and its scent fills the air.