22–5 Angiosperms—Flowering Plants Photo credit: ©Dorling Kindersley Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Flowers and Fruits The majority of living plant species are flowering plants, or angiosperms. Angiosperms are members of the phylum Anthophyta. Flowers and Fruits Angiosperms develop unique reproductive organs known as flowers. Flowers are an evolutionary advantage because they attract animals, which then transport pollen from flower to flower. This is much more efficient than wind pollination. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Flowers and Fruits Flowers contain ovaries, which surround and protect the seeds. The presence of an ovary gives angiosperms their name; it means “enclosed seed.” After pollination, the ovary develops into a fruit. A fruit is a wall of tissue that surrounds a seed. A fruit protects the seed and aids in its dispersal. Animals that may eat the fruit, and its seeds, can carry the seeds many kilometers and increase the range of the angiosperm. Copyright Pearson Prentice Hall

Diversity of Angiosperms Angiosperms are categorized in many ways: monocots and dicots woody and herbaceous plants annuals, biennials, and perennials An angiosperm can belong to more than one category. Copyright Pearson Prentice Hall

Diversity of Angiosperms Monocots and Dicots  Monocots and dicots are named for the number of seed leaves, or cotyledons, in the plant embryo. Monocots have one seed leaf, and dicots have two. A cotyledon is the first leaf or the first pair of leaves produced by the embryo of a seed plant. Other differences include the distribution of vascular tissue in stems, roots, and leaves, and the number of petals per flower. Monocots: corn, wheat, lilies, orchids, palms Dicots: roses, clover, tomatoes, oaks, daisies Copyright Pearson Prentice Hall

Diversity of Angiosperms Monocots and dicots are named for the number of seed leaves, or cotyledons, in the plant embryo. The table compares the characteristics of monocots and dicots. Copyright Pearson Prentice Hall

Diversity of Angiosperms Monocots and dicots are named for the number of seed leaves, or cotyledons, in the plant embryo. The table compares the characteristics of monocots and dicots. Copyright Pearson Prentice Hall

Diversity of Angiosperms Woody and Herbaceous Plants Woody plants are made primarily of cells with thick cell walls that support the plant body. Woody plants include trees, shrubs, and vines. Plant stems that are smooth and nonwoody are characteristic of herbaceous plants. Herbaceous plants do not produce wood as they grow. Herbaceous plants include dandelions, zinnias, sunflowers, and petunias. Copyright Pearson Prentice Hall

Diversity of Angiosperms Annuals, Biennials, and Perennials Plant life span is determined by genetic and environmental factors. There are three categories of plant life spans: annual, biennial, and perennial. Annuals are plants that complete a life cycle in one growing season. They grow from seed to maturity, flower, produce seeds, and die all in the course of one growing season. (marigolds, petunias, zinnias, etc) Copyright Pearson Prentice Hall

Diversity of Angiosperms Biennials complete their life cycle in two years. In the first year, they germinate and grow roots, short stems, and sometimes leaves. In the second year, they grow new stems and leaves, produce flowers and seeds, and die. (evening primrose, parsley, celery, foxglove) Perennials live for more than two years. Many have herbaceous stems that die each winter and are replaced in the spring like peonies, asparagus, and many grasses. Most have woody stems like palm trees, sagebrush, maple trees, and honeysuckle. Copyright Pearson Prentice Hall