Alnus

例句：

1. 1. The white pine trees stand tall in the forest.
   森林里的白松树高耸入云。
2. 2. Alnus trees are known for their strong branches and beautiful leaves.
   白杨树因其强壮的树枝和美丽的叶子而闻名。
3. 3. In ancient times, alnus was used to make paper by boiling down the wood of the tree.
   在古代，白杨木被用来造纸，通过煮沸树木的木材制成。