翁草

Literally, “old man grass”, 翁(おきな) (okina, “old man”) + 草(くさ) (kusa, “grass”). The kusa changes to gusa as an instance of rendaku (連濁).

翁(おきな)草(ぐさ) or 翁草(オキナグサ) • (okinagusa) 

1. narrow-leaf pasque-flower, Pulsatilla cernua

   Synonyms: 桂仙花 (keisenka), 白頭翁 (hakutōō)

2. synonym of 松 (matsu, “pine”)
3. synonym of 菊 (kiku, “chrysanthemum”)

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