In most species, two or more carpels are fused into a single structure; the result is an ovary with two or more chambers, each containing one or more ovules. The term pistil is sometimes used to refer to a single carpel or two or more fused carpels. A stamen con-sists of a stalk called the filament and a terminal structure called the
anther; within the anther are chambers called microsporangia (pollen sacs) that produce pollen