also: やちくさ
noun
great variety of plants; many kinds of herbs
Literary or poetic term for a lush, diverse collection of plants or herbs, often evoking a natural, abundant landscape.
野原には八千草が生い茂っていた。
The field was thick with a great variety of plants.
春になると、八千草が一斉に芽吹く。
In spring, many kinds of herbs sprout all at once.
千草 also means 'a great variety of plants' but is more common and less emphatic than 八千草, which implies an even larger, more abundant variety.
Compound of 八千 (yachi, 'eight thousand', meaning 'a great many') and 草 (kusa, 'grass, plant'). The exact historical derivation is uncertain, but the word is conventionally associated with the idea of countless plants.