birch

In Finland purists insist that only birch bark should be added.

在芬兰，纯化论者坚持说只能加白桦树皮。

After a lovely stretch running right along the edge of Lake Baikal we moved away from birch and pine tree territory into lusher pastures.

在沿着贝加尔湖的一段美妙行程之后，我们离开了桦树和松树的地域，进入了令人迷醉的大草原。

This also explains why some migrants from east Asia to northern Europe suddenly develop an allergic reaction to jackfruit once they have come into contact with birch pollen.

这也解释了为什么来自东亚的某些移民，到了北欧后，一旦接触到桦树花粉，会突然出现菠萝蜜过敏反应的现象。