生い茂る

1. Origins, structure, and basic meaning

• Structure: 生い茂る (おいしげる) is an intransitive verb meaning for grass or trees to grow thick and luxuriant.
• Basic usage: 草が生い茂る states that plants grow densely, while 生い茂る森 modifies a place characterized by such growth.
  • 道の両側には背の高い草が生い茂っています。 — Tall grass grows thick on both sides of the road.
  • 木々が生い茂る森の中は昼でも薄暗いです。 — The forest is dark even during the day because the trees are so dense.

2. Common pitfalls and similar expressions

• Grow and grow densely
  • 育つ covers growth broadly, whereas 生い茂る specifically emphasizes vegetation becoming thick enough to cover an area densely.