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

1. 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 OFANTHER
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 OFANTHERS
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