Fetching details from the dictionary...

leaf; blade (of grass); (pine) needle
「葉」 has another reading with different meanings.
秋になると葉が落ちます。
Leaves fall when it becomes autumn.
秋になると葉が落ち始める。
Leaves are falling.
秋になると、木の葉が黄色くなります。
When autumn comes, the tree leaves turn yellow.