这是因为当时茶叶经常由野生茶树制成。

That's because the tea then was often made from wild tea leaves.

youdao

碧螺春茶叶用春季从茶树采摘下的细嫩芽头炒制而成；

Biluochun is made by fried tender bud which is picked off in the spring.

youdao

碧螺春茶叶用春季从茶树采摘下的细嫩芽头炒制而成；

Biluochun is made by fried tender bud which is picked off in the spring.

youdao