Cohesion of Stamens:
Stamens of a flower may remain united among themselves. It is called the cohesion of stamens. The union may involve only the filaments or only in the anthers or along their length including both filaments and anthers. The cohesion of stamens may be of three types-
1. Adelphous: The stamens are fused by their filaments only, the anthers are free.
2. Syngenesious: When the stamens are united by their anthers only, the filaments are free.
Example: Helianthus annuus, Tagetes patula, etc.
3. Synandrous: When the stamens are united both by their filaments and by their anthers.
Example: Cucurbita maxima.
Adhesion of Stamens:
When the stamens remain united with members of different floral whorls, stamens with petals, stamens with carpels, etc, the phenomenon is called adhesion of stamens. Adhesion of stamens may be of three types-
1. Epipetalous: When the stamens are united with petals the condition is known as epipetalous. Generally, the filaments remain united with the petals and anthers remain free.
Example: Daturia metel, Ocimum sanctum, etc.
2. Epiphyllous: In this type, the stamens are united with the perianth as in tuberose.
3. Gynandrous: In this type, the stamens adhere to the carpels. When the union between stamens and carpels is complete, the condition is called gynostegium or gynostemium.