Plant Reproduction
Introduction
• A flower has a set of adaptations– Petals have modified leaves– Entire flower is a highly modified branch
• Flower shape, scent, color attracts insects, thereby ensuring the reproduction of the plant
Flower
• Function– To produce seeds for reproduction
Terminology
• Whorl– Arrangement of three or more leaves,
petals, or other organs radiating from the plant
• Non-essential flower parts – Not directly involved in reproduction
• Essential flower parts– Directly involved in reproduction
Parts of the Flower
• Receptacle– Base of the flower
Parts of the Flower
• Sepals– Non-essential parts of the flower– Compose the first whorl– Collectively
known as the calyx
Parts of the Flower
• Petals– Non-essential parts of the flower
• Compose the second whorl• Collectively known as the corolla
Parts of the Flower
• Stamen– Essential flower parts
• Compose the third whorl• Male reproductive organ
–Anther : Produces pollen (contains sperm cells)
–Filament : Supports the anther
Parts of the Flower
• Carpels– Essential flower parts– Compose the last, fourth whorl– Usually fused to make a single pistil– Female reproductive organ
Carpels vs. Pistils
• (A) shows a single pistil consisting of several fused carpels
• (B) shows several pistils, each consisting of a single carpel
Parts of the flower
• Female reproductive organ– Ovary : Swollen base of the pistil (contains
ovules, which contain egg cells)– Style: Stalk of the pistil– Stigma: Tip of the pistil, sticky to capture falling
pollen
Types of Flowers
• Perfect– Has both pistils and
stamens in the same flower– Have all 4 whorls of modified leaves
• Imperfect– Has either pistil or stamens in the same flower– Missing one or more flower parts – Two types
• Monoecious• Dioecious
Imperfect Flowers
• Monoecious– “Same house”– Separate male and female flowers on the
same plant– Example
• Corn
Imperfect Flowers
• Dioecious– “Two houses”– Flowers are all male or all female on the
same plant– Example
• Ginko tree–Most are male–Female produces seeds with foul odor
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