1. Polyandrous: Polyandrous androecium is that in which stamens of flower are free and not fused with each other.
2. Monadelphous: When the filaments of stamens are fused to form one cluster, that type of androecium is known as monadelphous androecium. Anthers present on tip are not fused.
3. Diadelphous: When the filaments of stamens are fused in two clusters, that type of androecium is known as diadelphous androecium.
4. Polyadelphous: In polyadelphous androecium, numerous filaments are fused to form multiple groups