All the stamens of a flower are collectively called the androecium (plural androecia) this is sometimes referred to as the male part of the flower although strictly speaking only the gametes are male or female. A stamen consists of a filament and an anther. The anthers consist of four fused chambers called microsporangia. It is in these chambers that the pollen is produced which contains the male gametes and must be transferred to the pistil for fertilisation to take place. Some flowers bear only stamens and are sometimes referred to as male flowers, the correct term however is staminate.
There is considerable variation in the androecium, for example plant species differ with regard to:
The number of stamens
|The number of stamens may differ greatly in the flowers of plants from different families. For example some grasses (Poaceae) have only one stamen, Mexican Blood Trumpet and Jacarandas (Bignoniaceae) have four stamens and Roses have several dozen.|
A rose showing the many stamens clustered in the centre of the flower.
The positions of the stamens within the flower
|The stamens may originate near the base of the pistil or they may be fused at their base with the petals and appear to originate out of the petal.|
Whether the stamens are fused or not
|The filaments or the anthers of the stamens may be fused. Two good examples of common flowers where the filaments are fused are peas and beans (Fabaceae) and the Hibiscus (Malvaceae).|
|A hibiscus flower. Notice how the stamen filaments are fused into a tube around the pistil.|
How the anther is attached to the filament
|On the right are three different ways in which the anther may be attached to the filament in a stamen. In A. the filament is attached to the base of the anther, in B. along the back of the anther and in C. to a point at the back of the anther.|