The pistillate whorl is very liable to changes.
p, Pistillate, s, staminate flowers; h, sterile flowers forming a circlet of stiff hairs closing the mouth of the chamber formed by the lower part of the spathe.
1), which are on one tree male (staminate) only, on another female (pistillate).
The flowers, which appear in early summer, are in pendulous, slender yellowish catkins, which bear a number of staminate flowers with a few pistillate flowers at the base.
The staminate contain 8 to 20 stamens which produce an enormous amount of dusty yellow pollen, some of which gets carried by wind to the protruding stigmas of the pistillate flowers.