Classification of Angiosperms The Flowering Plants By : Dr. M S Patil for 5th semester

Two Major Groups Monocots Dicots Single cotyledon Parallel veins Flowers in multiples of 3’s Dicots Two cotyledons Netted veins Flowers in multiples of 2, 4 or 5

Monocot and Dicot plant

FRUITS SIMPLE AGGREGRATE MULTIPLE Dry (poppy seed, milkweed, wheat) Fleshy (peach, plumb, apple, tomato, grape) AGGREGRATE Flowers with several carpels Raspberry, strawberry MULTIPLE Cluster of flowers Pineapple

Simple, aggregrate and multiple fruit

SEED STRUCTURES Micropyle Plumule Hypocotyl Opening through which the pollen tube grows to deliver pollen to the ovary (ovules) Plumule Epicotyl + embryonic leaves First leaves to emerge during germination Hypocotyl Stem like area between radicle and cotyledon

SEED STRUCTURES (2) Radicle Cotyledon Hilum Seed Coat Embryonic root First to emerge from the seed during germination Cotyledon Fleshy part of the seed; food storage for plant embryo until germination Hilum Seed scar; where seed was attached to the ovary wall Seed Coat Covers and protects the seed during dormancy

Typical Seed

Germination Dormancy How do you know germination has occurred? Leaves Allows seed to germinate when conditions are favorable How do you know germination has occurred? Radicle emerges Leaves Photosynthesis begins Cotyledons no longer needed

Factors that Trigger Germination Water Oxygen Temperature Light Fire Freezing temps. Animal digestive tract Hormones

Plant Hormones Auxins Regulate plant growth

Hormones (2) Cytokinins Gibberellins Abscisic Acid Ethylene Promotes cell division (roots and stems) Gibberellins Promote growth Stimulate germination Abscisic Acid Inhibits growth of buds and germination Ethylene Gas that stimulates ripening of fruits

Hormones (3) Oligosaccharins Regulate growth and development Defense against disease

TROPISM Plant movement towards or away from a stimuli EXAMPLES Phototropism (light) Thigmotropism (touch) Gravitropism (gravity) Chemotropism (chemical/hormones) Hydrotropism (water)

THE FLOWER The reproductive structure for the flowering plant Perfect Flowers Both stamens and carpels present Self or cross pollination Imperfect Flowers Either stamens or carpels present Cross pollination only

Female Reproductive Parts Essential Carpel Pistil (fused carpels) Stigma, style, ovary Stigma Sticky to trap pollen Style Tube from stigma to ovary Ovary Holds the ovules

Female Flower Parts C A R P E L

Male Reproductive Parts Essential Stamen Male reproductive part Anther and filament Anther Produces pollen Filament Supports the anther

Male Flower Parts

Nonessential Flower Parts Petal Attract pollinators Top whorl Sepal Protect developing flower Bottom whorl Corolla Both whorls

Nonessential Flower Parts

Flowers