Lesson 2 Seedless Plants Lesson 3 Seed Plants Lesson 1 What is a plant? Lesson 2 Seedless Plants Lesson 3 Seed Plants Chapter Menu

Plant Classification Plants Non Vascular Mosses Vascular Seedless (Spores) Ferns Seed Non Flowering Gymnosperms Angiosperms One way to classify plants is: non-vascular and vascular plants. Non-vascular Vascular Lesson 1-3

Plant Classification Plants Non Vascular Mosses Vascular Seedless (Spores) Ferns Seed Non Flowering Gymnosperms Angiosperms Lesson 1-3

Non-vascular Seedless Plants Non-vascular plants are called bryophytes, they have no vascular tissue, no true seeds, roots, stems or leaves. Because they lack vascular tissue, the bryophytes usually live in moist environments, they use diffusion and osmosis for nutrient transport. Non-vascular bryophytes Lesson 2-1

Instead of roots, they have rhizoids. Instead of stems, they have stalks. Lesson 2-1

Non-vascular Seedless Plants (cont.) Examples of non-vascular plants are mosses, liverworts, and hornworts. Mosses, the most common bryophytes, are small, green plants that usually grow in shady, damp environments. Lesson 2-1

Plant Classification Plants Non Vascular Mosses Vascular Seedless (Spores) Ferns Seed Non Flowering Gymnosperms Angiosperms Lesson 1-3

Vascular Seedless Plants Over 90 percent of plant species are vascular plants which contain vascular tissue in their roots, stems and leaves. There are two kinds of vascular plants: seedless and seed plants. Vascular Roots Stems Leaves Seedless seed Lesson 2-2

Plant Classification Plants Non Vascular Mosses Vascular Seedless (Spores) Ferns Seed Non Flowering Gymnosperms Angiosperms Lesson 1-3

Vascular Seedless Plants Examples of vascular seedless plants are ferns, club mosses and horsetails that reproduce using spores. seedless Ferns Spores Lesson 2-2

Vascular Seedless Plants (cont.) The fronds, or leaves of ferns, make up most of a fern. Ferns grow in a variety of habitats, including damp, swampy areas and dry, rocky cliffs. Steven P. Lynch Lesson 2-2

Vascular Seedless Plants (cont.) Unlike mosses, club mosses have roots, stems, and leaves. Steven P. Lynch Lesson 2-2

Vascular Seedless Plants (cont.) Horsetails have small leaves growing in circles around the stems. Horsetail stems are hollow, and the tissues contain silica, a mineral in sand, that makes them abrasive. S. Solum/PhotoLink/Getty Images Lesson 2-2

Plant Classification Plants Non Vascular Mosses Vascular Seedless (Spores) Ferns Seed Non Flowering Gymnosperms Angiosperms Lesson 1-3

Vascular Seed Plants There are two kinds of vascular seed plants: non-flowering gymnosperms and flowering angiosperms. Vascular seed Non-flowering gymnosperms flowering angiosperms Quarto, Inc./Photodisc/Getty Images Steven P. Lynch Lesson 3-1

Plant Classification Plants Non Vascular Mosses Vascular Seedless (Spores) Ferns Seed Non Flowering Gymnosperms Angiosperms Lesson 1-3

Gymnosperms Non-flowering gymnosperms produce seed in a cone. Examples of gymnosperms include conifers, cyads, ginkoes, and gnetophytes. Cone Siede Preis/Getty Images Lesson 3-2

Plant Classification Plants Non Vascular Mosses Vascular Seedless (Spores) Ferns Seed Non Flowering Gymnosperms Angiosperms Lesson 1-3

Angiosperms (cont.) Flowering angiosperms produce seeds in a fruit, fruits grow from flowers. CORBIS Lesson 3-3

Angiosperms There are more than 260,000 species of flowering plants, or angiosperms. Almost all of the food eaten by humans comes from angiosperms or from animals that eat angiosperms. Lesson 3-3

Characteristics of Seed Plants (cont.) All seed plants have vascular tissue, roots, stems, and leaves. Lesson 3-1

Characteristics of Seed Plants (cont.) There are two types of vascular tissue: xylem that carries water and nutrients, from roots to leaves and phloem that carries sugar from leaves to everywhere else. Xylem phloem

Characteristics of Seed Plants (cont.) Roots anchor a plant, either in soil or onto another plant or an object such as a rock. All root systems help a plant absorb water and other substance from the soil. Lesson 3-1

Characteristics of Seed Plants (cont.) The part of a plant that connects its roots to its leaves is the stem. Stems support branches and leaves, and their vascular tissues transport water, minerals, and food. Plant stems are usually classified as either herbaceous, which are usually soft and green, or woody, which are stiff and typically not green. Lesson 3-1

The top and bottom surface of leaves consists of epidermal tissue coated by a layer of cuticle to prevent water loss, and embedded by stomata to allow water evaporation and gas exchange. Dr. Gerald Van Dyke/Visuals Unlimited/Getty Images epidermal cuticle stomata Lesson 3-1

Characteristics of Seed Plants (cont.) Below the upper epidermis are rows of tightly packed cells called palisade mesophyll cells where photosynthesis mainly occurs. Lesson 3-1

Angiosperms (cont.) There are three kinds of growth methods: annual, biennials, and Plants that grow, flower, and produce seeds in one growing season are called annuals. Lesson 3-3

Angiosperms (cont.) Biennials complete their life cycles in two growing seasons. During the first year, the plant grows roots, stems and leaves. In the second growing season the plant produces new stems, leaves, flowers, and seeds. Lesson 3-3

Angiosperms (cont.) Perennial plants, like trees and shrubs, can live for more than two growing seasons. Flowering plants are organized into two groups—monocots and dicots. These groups are based on the number of leaves in early development, or cotyledons, in a seed. Lesson 3-3