Androecium

Androecium, flower parts, Male reproductive organ of the flower, stamen and filament

1. ANDROECIUM R. NITHYA M. Sc., M. Phil ., (Ph. D) ASSISTANT PROFESSOR DEPARTMENT OF BIOTECHNOLOGY SRI ADI CHUNCHANAGIRI WOMENS COLLEGE, CUMBUM, THENI DT, TAMILNADU

2. ANDROECIUM - Third whorl of flower - Male reproductive part - stamens or microsporophylls - stamen consists anther and filament

3. ANTHER Anther with single lobes- monothecous Anther with two lobes - dithecous

4. ATTACHMENT OF ANTHER Four types BASIFIXED The tip of the filament is attached to the base of the anther. E . g. Mustard

5. DORSIFIXED The filament is fixed at one position to the back of the anther. E.g. Nymphaea

6. VERSATILE The filament is attached in the middle of the anther. E.g . Grasses

7. ADNATE The filament is attached throughout the whole length of the back of the anther. E. g. Tobacco

8. DEHISCENCE OF ANTHERS Anthers lobes open to liberate the pollen grains Transverse dehiscence Longitudinal dehiscence Porous or Apical dehiscence Valvular dehiscence

9. TRANSVERSE DEHISCENCE The anther splits open transversely and the pollen grains are liberated

10. LONGITUDINAL DEHISCENCE Each lobe of the anther dehisces by a longitudinal slit

11. POROUS OR APICAL DEHISCENCE Lobe of the anther opens at the tip

12. VALVULAR DEHISCENCE - wall of anther opens like a lid or valve

13. UNION OF STAMENS OR COHESION OR ADNATION OF STAMENS Filaments or anthers are united by following ways Monadelphous Diadelphous Polyadelphous Syngenesious Synandrium

14. Monoadelphous Filaments united to form single bundle.

15. Diadelphous Stamens are united to form two bundles In these plants there are 10 stamens (9 + 1), (5+5)

16. Polyadelphous Filaments are united to form more than two bundles.

17. Syngenesious Filaments - free Anthers - united to form a tube

18. Synandrium Filaments united - column Anthers united - ring

19. ARRANGEMENT OF STAMENS Haplostemonous Stamens in one whorl opposite to sepals.

20. Diplostemonous Two whorls of stamens outer whorl - opposite sepals ( antisepalous ) inner whorl – opposite petals ( antipetalous )

21. Obdiplostemonous stamens in two whorls outer whorl - antipetalous inner whorl - antisepalous

22. LENGTH OF STAMENS Didynamous Four stamens - two longer and the two are shorter. E.g. Leucas

23. Tetradynomous Six stamens – two shorter and four are longer. E.g . Brassica

24. NATURE OF STAMENS Epipetalous Stamens are attached with the petals

25. Epiphyllous Stamens are attached with the perianth lobes

26. Staminodes Sterile stamens

27. POLLEN Pollen grains or microspores - pollen sacs All Pollen in a sac- pollen mass - pollinium

28. Thank you