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.
When only one of those organs is present the flower is unisexual or diclinous, and is either male (staminate), j, or female (pistillate), ?
Falling pistils mark the end of the developmental cycle of the individual pistillate calyx.
pistillate flowers from which the little red seed-bearing fruits develop.
pistillate plants show only a few pairs of primordial flowers.
In the case of unisexual flowers, whether monoecious, that is, with staminate and pistillate flowers on one and the same plant, such as many of our native trees - oak, beech, birch, alder, &c., or dioecious with staminate and pistillate flowers on different plants, as in willows and poplars, cross pollination only is possible.