Plant Anatomy

Definitions Anatomy

Study of form and basic organization. Morphology

Study of tissue organization. Physiology

Study of normal organism function.

Life Cycle Juvenile Adult Reproductive

Vegetative

Plant Structure Two main organ systems: shoot

and root Shoot

Above ground Leaves, buds, stems, flowers, fruits

Root Below ground roots, tubers, rhizomes

Plant Cells Formed at meristems.

Mitosis in meristem produces new cells.

Two types of meristems. Apical – produces primary growth, ex.

tip of root or shoot. Lateral – produces secondary growth,

ex. cambium.

Apical Meristem

Lateral Meristem

Cells are grouped into tissues. Dermal Ground Vascular

Cell Types

Epidermal

Ground

Vascular

Zea mays L. leaf cross section

Dermal Tissue Covers outer surface of

herbaceous plants. Composed of epidermal cells that

secrete the waxy cuticle. Waxy cuticle protects against

water loss.

Ground Tissue Bulk of the primary plant body. Composed of parenchyma,

collenchyma, and sclerenchyma.

Parenchyma

Parenchyma

pineapple

Collenchyma

Celery

Schlerenchyma

used to make rope

Vascular Tissue Transports food, water, hormone,

and minerals. Composed of xylem, phloem,

parenchyma, and cambium.

Vascular tissue

Xylem

Dutchmens pipe

Dicot stem

Vegetative Structures Roots Stem Leaf

Roots Tap root Fibrous root Adventitious root Tuberous root Aerial root

Roots

TaprootTaproots

Tuberous Fiberous

Stem Anatomy Bud – undeveloped shoot. Node – Location of leaf or bud on

stem. Internode – Space between nodes. Pith – Spongy tissue in the center of

the stem. Lenticel – Pore in the outer layer of

the stem.

Stem

Stem Modifications Tuber – underground stem with nodes Rhizome – underground stem with

buds Stolon – aboveground stem with shoot

buds Bulb – underground stem with fleshy

leaves Corm – underground stem with papery

leaves

Modified Stem

Thorn

Tendril

Onion set Rhizome

Modified Stem II

Asparagus Stolon

Growth Form Herb Shrub Tree Vine

Growth Cycle Annual – single season Biennial – two seasons Perennial – multiple seasons Evergreen – leaves persist > 2

seasons Deciduous – leaves die in cold or

dry

Leaf Parts Petiole Blade Stipule Axillary bud

Leaf Structure

Blade

PetioleAxillary Bud

Stipule

Leaf Arrangement Alternate Opposite Whorled

Leaf form Simple Compound

Pinnate Palmate

Vein Arrangement Pinnate Palmate Parallel Dichotomous

Dichotomous

Leaf Shape Ovate Elliptic Oblong Lanceolate Linear Orbicular

Cordate Hastate Sagittate Peltate Perfoliate Terete

Leaf Margins Entire Serrate Doubly serrate Dentate Crenate

Undulate Revolute Crisped Lobed

Misc. Vegetative Structures Thorns

modified stems (Honey Locust) Spines

modified leaves (Cactus) Prickles

epidermal outgrowth (Rose)

Reproductive Structures Flowers Fruits

Floral Parts Pedicel Sepal Petal Perianth Stamen Carpel Pistil

Flower

Floral Symmetry Actinomorphic (regular)

Many axes of symmetry,i.e.. the same wherever you cut it.

Zygomorphic One axis of symmetry, i.e.. can only cut one way.

Inflorescence Types

Solitary Spike Spadix Spikelet

RacemeUmbel

Whorl

CompoundUmbel

Panicle

Fruit Types Dry, indehiscent fruit Dry, dehiscent fruit Fleshy fruit Other

Dry, indehiscent fruits Achene (lettuce) Samara (maple) Caryposis (wheat) Nut (almond)

Dry, Dehiscent Fruit Legume (soybean) Capsule (tobacco) Silique (Arabidopsis) Schizocarp (maple)

Fleshy Fruits Drupe (peach, nectarine) Berry (tomato) Pepo (cucumber) Hesperidium (citrus) Hip (rose) Pome (apple, pear)

Other Fruit Types Aggregate

mature ovaries from separate pistils of one flower (ex. raspberry)

Multiple mature ovaries from separate pistils of

several flowers (ex. pineapple) Accessory

fruit is something other than ovary tissue (ex. strawberry is a swollen receptacle, seeds are achenes)

Placentation

Marginal Axile Parietal

Free central Apical Basal

Ovary Position

Hypogynous(above calyx)

Perigynous(within the floral cup)

Epigynous(below calyx)

Monocots vs. Dicots One cotyledon Parallel leaf veins Flower parts often

in multiples of three

Vascular bundles scattered in stem

Two cotyledons Netlike leaf veins Flower parts often

in multiples of 4 or 5

Vascular bundles in a ring in the stem

Other Anatomy Terms

Cell sketch

Roots

Leaf section

Other TermsGrape Cane Section