... with four leaves. Uncommon, occurring about one in ten thousand times, but it happens. More than four leaflets are possible, I have found several specimens with five and one with six. The highest documented count is twenty-one (Shigeo Obara, Japan).
A couple of days after I took the photos of the four-leaf clover I stumbled across a five-leaf. Not in very good shape, it looks like the grasshoppers found it before I did.