PLANTSTheir Forms and Functions

Plant as an

ORGANISM

Plant Kingdom

Vascular Plants

Spore-bearing Plants

Pteridophyta [Ferns and Horsetails]

Seed-bearing Plants

Gymnosper

ms

Angiosperms

Monocotyledons

Dicotyledons

Nonvascular Plants

Bryophytes [liverworts and mosses]

Algae

PLANTAE Kingdom

Parts of a

PLANT

Two Major Systems

Shoot System – plant parts above the ground, that are grouped into two:

• Vegetative Parts – consist of the stems and leaves

• Reproductive Parts – includes flowers, fruits and seeds

Root System – plant parts that are primarily found below the grounds .

Roots are usually an underground part of a plant. They anchor the plant and absorb water and minerals from the soil, acts as an important storage for some plants.

The root is distinguished from the stem by its structure, by the manner in which it is formed, and by the lack of such appendages as buds and leaves.

The ROOTS

External Parts of the Roots

Secondary roots – these are roots that branch from the primary root.

Root hairs – these are epidermal cells grow long projections into the surrounding soil.

Primary root – elongates during germination of the seed.

Root cap – it is a thimble like cluster of cell that covers and protects the root tip.

Internal Parts of the Plant Root

Region of Maturation – cell mature and differentiate into special tissue

Region of Cell Division - The Root Aparical Maritem is the area of cell division found in the root tip

Region of Elongation - cells become two to three times longer and a little longer than the original size.

Xylem PhloemRoot hair

Vascular Cylinder

Cortex

Endodermis

Epidermis

Apical Maristem Root Cap

Two Root Systems

Fibrous Root Taproot

Fibrous Root System - It has many slender roots of about the same size that spread out in all directions

Taproot System - A plant with a taproot system has one root that is larger than the rest. Taproots grow straight down, some as deep as 15 feet.

The

STEM A plant organ that typically grows above ground and bears leaves, buds, and flowers. Stems conduct water and minerals from the roots to the leaves and also transport food made in the leaves to all other parts of the plant. In addition, stems give support to the plant and may also store food and water, act as reproductive structures, and may themselves manufacture food.

Main Kinds of Stem

Herbaceous StemHerbaceous

plants are usually green and pliant and are covered by a thin epidermis instead of by the bark of woody plants.

Woody StemA woody plant is

a vascular plant that has a perennial stem that is above ground and covered by a layer of thickened bark. The diameter of a woody stem id dramatically larger than the woody stem and can sustain life longer than the herbaceous stem

Internal Parts of the Stem

Pith

Cortex

Outer Skin

Cambium

Xylem

PhloemPith

Outer Skin

Vascular Bundle containing Xylem and Phloem Tissue

External Parts of the Stem

Node

Axillary Bud

Lateral Buds

Terminal Bud Bud Scale

Internode

• Lenticels

• Leaf Scar

Specialized Stems

Runners – these allow the stem to develop new roots and leaves wherein a node of the stem touches the soil.

Rhizomes – these are underground, horizontal stem where new shoots develop.

Bulbs – these are consisting of small piece of stem that bears fleshy leaves.

Tendrils – these are long, thin, coiling structures that attach the plant for support or adhere to surfaces and enable it to climb.

Tubers – have a short terminal portion of an underground that develop buds at the nodes.

Corms – these are short, bulky, vertical stem that bears fleshy leaves.

The LEAFLeaf, part of a plant that serves primarily as the plant's

food-making organ in a process called photosynthesis. Leaves take part in other plant functions as well, including transpiration, of which plants remove excess water from itself, and respiration, the process by which a plant obtains oxygen and energy. Leaves also may store food and water and provide structural support.

Small Netted Vein

Vein

Stipule

Blade

Midrib

Petiole

External Parts of the Leaf

Epidermis

Palisade Mesophyll

Guard Cells

Spongy Mesophyll

Veins

Stomata

Internal Parts of the Leaf

Variations in LeafArrangement on Stem

Alternate – Only one leaf is attached to a node and the Leaves are attached alternately.

Opposite - Two leaves are attached to one node. The leaves are opposite each other.

Whorled – Three or more leaves are attached to one node.

Variations in LeafArrangement on Stem

Alternate – Only one leaf is attached to a node and the Leaves are attached alternately.

Opposite - Two leaves are attached to one node. The leaves are opposite each other.

Whorled – Three or more leaves are attached to one node.

Compound Leaf - A compound leaf is deeply divided into separate parts called leaflets.

Simple Leaf - A simple leaf has only one blade and one petiole. The blade may be lobed, but it is not completely divided into separate parts.

Divisions in Leaves

Different Kinds of Compound Leaves

Palmately Compound Leaf - A palmately compound leaf has leaflets attached to one petiole. The leaflets spread from the base of the leaf like fingers on a hand.

Pinnately Compound Leaf - Pinnately compound leaf such as those of hickory and walnut has leaflets that are attached along both sides of the petiole.

Shape of LeafRound Shape

Heart Shaped

Straight

Elliptical

Leaf MarginSmooth

Toothed

CiliatedCrenate

Crenulate

Serrated

Revolve Undulate

Lobed

Netted Venation

• Palmately Netted Venation• Pinnately Netted Venation

Parallel Venation

• Palmately Parallel Venation• Pinnately Parallel Venation

Venation

The FLOWER

A A flower grows from a receptacle, which is the swollen tip of a flower stalk. All flower parts are actually modified leaves. Flowers are the reproductive organ of most seed-bearing plants. Flowers carry out the multiple roles of sexual reproduction, seed development, and fruit production. Many plants produce highly visible flowers that have a distinctive size, color, or fragrance.

Major Parts of the Flower

Corolla

Calyx

Petal

Sepal

Stigma

Style

Ovary

Anther

Filament

Pistil

Stamen