Counting stamens

In this Key a single stamen is assumed to have a single anther, made up of two pollen compartments, and a single filament:

Sometimes it is easier to count anthers or pollen compartments instead of stamens. For example, in some flowers the stamen filaments may be completely fused:

Pollen compartments often open by longitudinal or transverse slits, or by pores, to release the pollen contained inside. Open compartments can be more difficult to count than unopened compartments.