Scientific Identification & Classification

Scientific Identification & Classification

Plant Parts

• Leaves• Stems• Roots• Flowers

Leaves-External

• Petiole-leaf stalk or part that connects the leaf to the stem

• Blade-the large, flat part of the leaf• Midrib-the large center vein• Veins-the structural framework of

the leaf• Margin-the edge of the leaf

Leaves-External

Leaf Retention

• Evergreen-Leaves stay on the plant all year long

• Deciduous-Leaves will fall off during the dormant periods

• Herbaceous-leaves and stems die back at the end of the season

Leaf Type

Leaf Type

AwlsScales

Needles

Leaf Shapes

Cordate Elliptical Ovate Spatulate Deltoid

Lanceolate Liner

Leaf Margin

Leaf Arrangement

Alternate Opposite Whorled

Vein Pattern

Bracts – modified leaves to attract pollinators

Sessile – leaves without a petiole

bract

Real Flower

What are the functions of

leaves?• Capture light• Exchange gases through respiration• Provide a site for photosynthesis

• Some leaves store food and water• Release water through transpiration

cooling the plant

Stems• Movement of Materials

• Support of the leaves and reproductive structures

• Food storages

• Reproduction with stem cuttings or grafting

Stems-External• Lenticels

• Bud scale scars

• Leaf Scars

• Terminal bud

• Axillary or lateral bud

Thorns & Prickles

ThornPrickle

Modified Stems

Stolon

Tuber

Cladophyll

Root Functions

• Anchor the plant and hold it upright

• Absorb water and minerals from the soil and conduct them to the stem

• Store large quantities of plant food• Propagate or reproduce some

plants

Roots-External

• Root cap-indicates growth of new cells

• Root hairs-absorb moisture (water) and minerals

Root images from a rice plant

Root Types

Fibrous Roots

Tap Root

Taproots• Advantages• Penetrates

deeper• Obtain water

from other levels

• Anchor plant

• Disadvantages• Difficult to

remove or harvest

• do not stabilize well

Primary Roots• Grow down into the soil

and may branch repeatedly into lateral roots

• Taproot is a primary root

Fibrous• Advantages• Shallower,

better for fertilization & Water

• Stabilize in soil better

• Disadvantage• Less drought resistant• Tend to get exposed during

cultivation

Fibrous Root• Root structures in which the

primary and lateral roots develop equally so there is not a definite taproot.

Adventitious• Came from stems

or leaves instead of another root

• Prop root of corn and grapes are examples that give support

Storage Roots• Are structures such as those

of carrots and sweet potatoes which are used for food storage.

What do stems and roots have in

common?• Both have xylem and

phloem cells for transport.

Flowers

• Sepals-Green parts that cover and protect flower bud before it opens

• Petals-are really leaves that are modified to attract insects for flower pollination, the pretty part that we call flowers

• Stamen-male part of the flower• Pistil-female part of the flower

Flowers

Parts of the Stamen

• Filament-short stalk that holds up the anther

• Anther-a sac-like structure that contains pollen, the male sex cells

Parts of the Pistil

• Stigma-sticky part on top of style where insects leave pollen

• Style-holds up the stigma and connects it to the ovary

• Ovary-if fertilized becomes a fruit or seed coat

• Ovules-the eggs or female sex cells that become seeds if fertilized

Complete-vs-Incomplete

• Complete flowers have both male and female parts

• Incomplete flowers have only male or female parts

Monoeciuos• All male or all female flowers on

plant• Examples: Hollies or Ginkgo

Male Female

Dioecious• Male and female, imperfect flowers

on same plant• Examples: Squash & Pumpkin

Flower Types

Corymbs Panicle

Spike

Flower Types

UmbelHead

Plant Parts-Fruit

• Cones• Nut (acorn)• Clusters or drupes (raspberry)• Capsules (willow)• Samara (maple)

Fruits and Nuts

Cones Acorns

ClusterDrupe

Fruits and Nuts

SamaraCapsule

Pome

Life Cycle• Annual-a plant that lives for only 1

year or less

• Biennial-a plant that lives for 2 years, usually flowering in the second year

• Perennial-a plant that lives for more than 2 years

Growth Habits• Trees: greater than 12 feet tall

• Shrubs: less than 12 feet tall

• Vines: a plant that climbs & spreads

Growth Habits• House Plant: plant grown indoors

• Bedding Plant: a plant used in flowering beds

Forms of Plants:Growth Pattern

Spreading

Weeping

Columnar

Growth Forms

Round Oval Pyramidal