Classification of Plants CHAPTER 28

Plant Kingdom Non-flowering Plants Flowering Plants

Non - flowering Plants Do NOT produce flowers . 3 groups Non - flowering Plants Mosses Ferns Gymnosperms Do NOT produce flowers

A plant can be divided into 3 parts

Examples of Mosses

Spore-producing capsule Moss spores

Characteristics of Mosses .Simplest plants .No true roots, No vascular tissues (no transport) .Simple stems & leaves .Spores from capsules (wind-dispersal) .Have rhizoids for anchorage .Damp terrestrial land

Fern

A leaf (finely divided into small parts) Fern A leaf (finely divided into small parts) underground stem root

spore-producing organs (circinate) young leaf

Characteristics of Ferns .roots, feathery leaves & underground stems .have vascular tissues (transport & support) .Spore-producing organ on the underside of leaves (reproduction) .Damp & shady places

Gymnosperms Pine tree

needle-shaped leaves

Male cones (in clusters) Female cones (scattered)

Characteristics of Gymnosperms .tall evergreen trees .roots, woody stems .needle-shaped leaves .vascular tissues (transport) .cones with reproductive structures .naked seeds in female cones .dry places

Flowering Plants . 2 groups Monocotyledons Dicotyledons . roots, stems, leaves . vascular tissues (transport) . flowers, fruits (contain seeds)

Monocotyledons Parallel veins

Characteristics of Monocotyledons . one seed-leaf leaves have parallel veins . herbaceous plants . e.g. grass, maize

Dicotyledons Veins in network

Characteristics of Dicotyledons . two seed-leaves . leaves have veins in network . e.g. trees, sunflower, rose

Plant Classification Plants Non-flowering Flowering 1 seed-leaf 2 seed-leaves Spore-bearing Naked seeds Monocots Dicots Gymnosperms No roots with roots Mosses Ferns

Plant Structure and Function CHAPTER 29

Stem The main body of the portion above ground of a tree, shrub or herb. The ascending plant axis. Have buds.

Stem Functions Support of other plant organs. Ps. Storage (water and food).

Modified Stems 1. Rhizomes 2. Stolons 3. Tubers 4. Tendrils

Rhizome An elongated underground horizontal stem. Ex: Iris, many grasses

Stolon An elongated above-ground horizontal stem. Ex: Strawberries Airplane Plant

Tuber A much-enlarged, short, fleshy underground stem tip. Ex: Dahlia, Potato

Leaf Lateral outgrowths of the stem axis. Primary photosynthetic organs. Function: Photosynthesis Storage

Leaf Modifications 1. Tendrils: for support 2. Bulbs: for food storage Ex: Peas 2. Bulbs: for food storage Ex: Onion 3. Insect Catching Ex: Carnivorous Plants 4. Flowers: thought to be modified leaves.

Other Modifications of Leaves Tendrils Spines Succulent Leaves Bracts

Root The descending axis of a plant, normally below ground. Functions: Anchorage. Absorption of water and minerals. Storage.

Root Types Taproot - one main root. Ex: carrot Fibrous Roots - many small roots of equal size. Ex: grass roots

Other Root Types

Sexual Organs 1. Flowers 2. Fruits 3. Seeds

Flowers Modified leaves grouped together on a stem. Sexual reproductive organs. Function: Sexual Reproduction

Fruit A mature ovary, sometimes including other floral parts. Function: Seed dispersal Seed protection

Fruits

Seed Mature ovule containing the embryo and nutrient tissues. Function: Dispersal unit in sexual reproduction.

Main Tissue Systems 1. Dermal 2. Vascular 3. Ground

Dermal Tissue Epidermis or "skin" of the plant. Often has a cuticle, a waxy coating to prevent water loss. Functions: Prevent water loss. Water absorption (root hairs).

Vascular Tissue Made of Xylem and Phloem. Functions: Transport and support Xylem - Water Phloem - Food

Phloem

Phloem Sieve Cell – alive when functioning, but lacks a nucleus. Companion Cell – alive, controls itself and the sieve cell.

Root Hairs Extensions of the epidermis to increase surface area for water absorption. Not a true tissue. Comment - root hairs are very delicate and must be continually replaced.

Root Hairs

Leaves Stem outgrowths for Ps. Leaf Morphology: 1. Gross 2. Fine

Gross Morphology Blade - the flattened portion of a leaf. Petiole - stalk of a leaf.

Axillary Buds Blade Petiole

Blade/Leaf Types Simple - 1 blade. Compound - Several blades.

Nodes and Internodes Node - stem area where a leaf and bud are attached. Internode - stem area between nodes.

Nodes } Internode

Fine Morphology The tissues within a leaf. 1. Upper Epidermis 2. Mesophyll 3. Lower Epidermis 4. Veins

Upper Epidermis Cuticle present. Usually 1 cell layer thick. Cells w/o chloroplasts . Function: protects the mesophyll.

Mesophyll 1. Palisade upright cells. 2. Spongy loosely organized cells with air spaces. Function: major sites for Ps. Epidermis Epidermis

Lower Epidermis Cuticle present. Usually 1 cell layer. Cells w/o chloroplasts. Stomata present for gas exchange.

Stomata (mouth) Regulated by Guard Cells which have chloroplasts.