靫草

Literally, “quiver grass”, 靫(うつぼ) (utsubo, “quiver”) + 草(くさ) (kusa, “grass, plant”). The kusa changes to gusa as an instance of rendaku (連濁).

靫(うつぼ)草(ぐさ) or 靫草(ウツボグサ) • (utsubogusa) 

1. common self-heal, Prunella vulgaris subsp. asiatica

   Synonyms: 夏枯草 (kakosō), 死人の枕 (shibito no makura)

As with many terms that name organisms, this term is often spelled in katakana, especially in biological contexts (where katakana is customary).