Flower Anatomy: Androecium & Gynoecium

• Thalamus is the uppermost terminal swollen part of the pedicel.
• It may be flat, convex, concave, or cup-shaped.
• It holds the four whorls of the flower.

Androecium

• The stamen is the male part of a flower.
• Stamen structure consists of a thin stalk or filament and a bilobed anther.
• The anther and filament are connected by connective tissue.
• Each anther lobe contains two pollen sacs which contain pollen grains.
• Androecium Function: It acts as a male part of the flower and produces pollen grains.
• Pollen grains take part in reproduction.
• The collective term for all the stamens is androecium.

Gynoecium

• The gynoecium is the fourth and central whorl of the flower.
• The individual segments or units that make it up are carpels or pistils.
• Structure: Its individual segments can include one or more carpels in a flower.
• The collective term for the carpels is gynoecium.
• The pistil is differentiated into the stigma which is the terminal receptive part, the style which is the middle tubular part, and the ovary, which is the basal swollen part.
• The ovary contains ovules
• Ovules fuse with pollen grains during fertilization and give rise to fruit and seeds.
• Gynoecium Function: Acts as a female part of the flower, produces ovules that ripen into seed, and helps in reproduction.

Calyx

• The calyx, the outermost whorl of a flower
• Its individual segments are called sepals and are green leaf-like structures.
• The collective term for all sepals is calyx.
• Calyx Function: It protects the inner floral whorls during the bud formation and takes part in photosynthesis.
• In some flowers, sepals become colored and are called petaloid.

Corolla

• Corolla is the second whorl of the flower
• Its individual segments or units are called petals.
• The collective term for the petals is Corolla.
• Petals are brightly colored with nectar to attract insects.
• These insects act as agents of pollination.

Parts and Whorls

• Flowers do not have all four whorls.
• Flowers with androecium or gynoecium only are called unisexual flowers
• Examples of unisexual flowers include papaya, palm, and gourd
• Flowers with both androecium and gynoecium are bisexual or hermaphrodite flowers
• Examples of hermaphrodite flowers include China rose, petunia, mustard, and pea

Activity 1 Conclusion

• The main parts of a flower are sepals, petals, stamen, and carpel
• Stamen and carpel are the reproductive parts.

This section discusses the androecium and gynoecium, which are the male and female reproductive parts of a flower. It describes the structure and function of the stamen (male) and pistil (female) including their roles in pollen production and reproduction.