Chapter 21
Lecture Outline
Flowering Plants
and Civilization
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Outline

Origin of Cultivated Plants

Selected Families of Flowering Plants
Dicots
Monocots
–
The Buttercup Family (Ranunculaceae)
–
The Grass Family (Poaceae)
–
The Laurel Family (Lauraceae)
–
The Lily Family (Liliaceae)
–
The Poppy Family (Papaveraceae)
–
The Orchid Family (Orchidaceae)
–
The Mustard Family (Brassicaceae)
–
The Rose Family (Rosaceae)
–
The Legume Family (Fabaceae)
–
The Spurge Family (Euphorbiaceae)
–
The Cactus Family (Cactaceae)
–
The Mint Family (Lamiaceae)
–
The Nightshade Family (Solanaceae)
–
The Carrot Family (Apiaceae)
–
The Pumpkin Family (Cucurbitaceae)
–
The Sunflower Family (Asteraceae)
Origin of Cultivated Plants

1880’s - Alphonse de Candolle, Origin of
Cultivated Plants
•


Cultivated plants originated in areas where wild relatives
grow.
1916 - N. I. Vavilov
•
Plants were domesticated in geographic regions with high
genetic diversity of wild relatives.
•
Majority of domesticated plants originated from mountain
regions.
1950’s - Jack Harlan and students
•
Associated crop origins with regions
Origin of Cultivated Plants

Cultivated plants appear to have originated in
six major regions:
•
Near-eastern region - Mediterranean, northern
Europe
–
•
Chinese region - Temperate and southern China
–
•
Barley, wheat, peas, lentils, asparagus, beets, carrots,
turnips, olives, cherries, plums, apricots, apples, onions,
garlic, broccoli, lettuce, flax, pistachios
Bamboo, peach, walnut, ginger, gourds, camphor, tea,
soybean, buckwheat, horseradish, cucumber
African continent - Mostly Ethiopia and West Africa
–
Yams, sorghum, okra, sweet melons, coffee, some cotton
Origin of Cultivated Plants

Cultivated plants appear to have originated in
six major regions:
•
South Asia and Pacific Islands
–
•
North America
–
•
Sugar cane, eggplant, mango, banana, citrus, safflower,
nutmeg, clove, cardamon, turmeric, black pepper,
coconut, taro, rice, sesame, onion
Sunflower, cranberry, blueberry, tobacco
South and Central America
–
Garden beans, corn, peanut, white potato, lima beans,
cashew, pineapple, avocado, red pepper, tomato, cotton,
cocaine, cacao (chocolate), sweet potato, pumpkin,
squash, rubber, vanilla, cassava
Selected Families of Flowering Plants

Dicots (now recognized in
two groups)
•
The buttercup family
(Ranunculaceae)
–
Nearly all 1,500 species are
herbaceous.
–
Petals vary in number.
–
Numerous stamens
–
Several to many pistils with
superior ovaries
–
Concentrated in north temperate and arctic regions
–
Most at least slightly poisonous.
Buttercup
Dicots – The Buttercup Family
Columbine
Hepatica
• Five spurred petals
Monkshood or wolfsbane
• Yields aconite - Drug once used to treat rheumatism and neuralgia.
• Very poisonous
• Wolf hunters used juice from roots to poison wolves.
Dicots – The Laurel Family (Lauraceae)

About 1,000 species of tropical evergreen shrubs and trees

No petals, but sepals sometimes petal-like.

Stamens in three or four whorls.
•
Anthers open by flaps that lift up.

Cinnamon - Pulverized
bark of small tree

Cassia

Camphor - Cold
remedies, insecticides

Sassafras trees - Native
to eastern U.S.

Sweet bay - Flavoring in
meat dishes

Avocado
California bay
Dicots – The Poppy Family (Papaveraceae)

Herbs of temperate and
subtropical regions

Numerous stamens, but
single pistil

Milky or colored sap

All species produce
alkaloidal drugs.

Opium poppies
•
•
•
•
Opium - White fluid from
capsules
Morphine and codeine
– Heroin
Papaverine and noscapine
Poppy seeds
Prickly
poppy flower
Dicots – The Mustard Family (Brassicaceae)

Nearly all 2,500 species in
temperate and cooler regions of
North America.

Four flower petals arranged in a
cross.

Six stamen: 2 short, 4 long

Fruits = siliques or silicles

All produce pungent watery juice.

Many cultivated edible plants:
•
•
Cauliflower, brussels sprouts,
broccoli, radish, turnip, horseradish,
watercress, rutabaga
Mustard - Ground seeds of two
species of Brassica
Shepherd’s purse
Dicots – The Rose Family (Rosaceae)

More than 3,000 species of trees, shrubs and herbs

Flowers have basal parts fused into cup, with petals,
sepals and numerous stamens attached to cup’s rim.

Family subdivided into subfamilies on basis of flower
structure and fruits.
Dicots – The Rose Family (Rosaceae)

Enormous economic impact:
•
Stone fruits: cherries, apricots, peaches, plums
•
Pome fruits: apples, pears
•
Aggregate fruits: strawberries, blackberries, raspberries
•
Garden ornamentals - Roses
•
Fragrances
•
Fruits of roses = hips - Vitamin C
Raspberry
Rose hips
Dicots – The Legume Family (Fabaceae)

Third largest of flowering plant families with 13,000
species

Cosmopolitan

Flowers radial to bilateral.

Stamens fused into tube around ovary.
Bilateral flower
showing stamen
tube
Inflorescence of radial flowers
Dicots – The Legume Family (Fabaceae)

Fruit is a legume.

Many important crop
plants:
•
Peas
•
Beans
•
Soybeans
•
Peanuts
•
Alfalfa
•
Sweet clover
•
Licorice
•
Carob
Winged bean
Dicots – The Spurge Family (Euphorbiaceae)

In tropical and temperate regions

Several economically important plants
•
•
Cassava - Staple food in tropical regions
Para rubber tree - Crude rubber from latex of inner bark

Stamens and pistils produced in separate flowers.

Flowers often inconspicuous and lack corolla.
Poinsettia
Dicots – The Spurge Family (Euphorbiaceae)

Inflorescence = cyathium
•
Female flower elevated on stalk called gynophore and surrounded by
several male flowers that each consist of little more than an anther.
•
Male and female flowers inserted on a cup composed of fused bracts,
usually with glands on rim.
•
Sometimes surrounded by colored bracts (poinsettia)
Dicots – The Cactus Family (Cactaceae)

More than 1,500
species native
only to Americas
in dry,
subtropical
regions.

Leaves reduced
in size, often
spines.

Fleshy stems
Dicots – The Cactus Family (Cactaceae)


Flowers showy.
•
Numerous stamens,
petals and sepals
•
Inferior ovary
develops into berry.
Most have edible
fruit.
•
Prickly pear fruits
Dicots – The Mint Family (Lamiaceae)

3,000 species

Unique combination
of angular stems that
are square in cross
section, opposite
leaves, and bilaterally
symmetrical flowers

Ovary superior and
four-parted,
developing into four
nutlets.
Lamb’s ear mint
Dicots – The Mint Family (Lamiaceae)

Plants produce mint oils
•
Used medicinally and as
antiseptic in different parts
of the world.
•
Menthol used in
toothpaste, candies, gum,
liqueurs, and cigarettes.
•
Rosemary, thyme, sage,
oregano, marjoram, basil,
lavender, catnip,
peppermint, spearmint
Peppermint
Dicots – The Nightshade Family (Solanaceae)

3,000 species concentrated in tropics of Central and
South America.

Flowers have fused petals with stamens fused to corolla.

Superior ovary develops into berry or capsule.
Dicots – The Nightshade Family (Solanaceae)

Tomato, white potato, eggplant, peppers, tobacco, petunia

Many nightshades poisonous and some have drug uses.
•
Belladonna drug
complex:
–
Atropine - Shock
treatment, pain
relief
–
Scopolamine Tranquilizer
•
Capsicum from red
pepper - Gastric
stimulant
•
Jimson weed Asthma
•
Tobacco
Tomato harvester
Dicots – The Carrot Family (Apiaceae)

Approximately 2,000 members widely distributed in
Northern Hemisphere.

Savory-aromatic herbs, with dissected leaves, and petiole
bases that form sheaths around stem

Flowers small, numerous and
arranged in umbels.

Inferior ovary and two-lobed
stigma

Dill, celery, carrot, parsley,
caraway, coriander, fennel,
anise, parsnip

Some members poisonous.
•
Water hemlock - Socrates believed
to have died from ingestion.
Water hemlock
Dicots – The Pumpkin Family (Cucurbitaceae)

700 species of
prostrate or climbing
herbaceous vines

Flowers unisexual with
fused petals.

Male
flower
Female flowers with
inferior ovary of three
carpels
Female flower with inferior ovary
Dicots – The Pumpkin Family (Cucurbitaceae)

Includes many
important edible plants
•
Many have been
cultivated for so long
they are unknown in a
wild state.
•
Pumpkins, squashes,
cucumbers,
cantaloupes, gourds
Dicots – The Sunflower Family (Asteraceae)

Second largest flowering plant family with
about 20,000 species

Dandelions, lettuce, endive, chicory,
artichoke, dahlia, chrysanthemum, marigold,
sunflower, thistle

Tarragon - Spice in meat and pickle
Dicots – The Sunflower Family (Asteraceae)

Individual
flowers =
florets

Florets
arranged in
compact
inflorescence
that
resembles a
single flower.
Selected Families of Flowering Plants

Monocots - The grass family (Poaceae)
•
Flowers windpollinated and
highly specialized.
•
Calyx and corolla
are tiny scales.
•
Flowers protected
in boat-shaped
bracts.
•
Stigmas exposed
and feathery.
•
Leaf bases sheath
stems.
Monocots – The Grass Family (Poaceae)

Contains nearly all cereals
•

Wheat, barley, rye, oats, rice,
corn
Sugar cane - Six meters tall
•
Juice squeezed from cane,
then centrifuged.
–
Solids crystallized into table
sugar.
–
Dark remnant = molasses

Baskets, fibers, thatching
for huts

Citronella Oil
Sugar cane
Monocots – The Lily Family (Liliaceae)

Approximately 4,550
members that occur
in almost any area
supporting
vegetation

Flowers often large
and their parts are in
multiples of three,
with sepals and
petals often
resembling each
other.
Monocots – The Lily Family (Liliaceae)

Lilies, daffodils,
asparagus, sarsaparilla,
Aloe, onions, garlic

Meadow saffron Source of colchicine
used to treat
rheumatism

Bowstring hemps
(sansevierias) - House
plants; long fibers for
string, rope, bowstrings
Sansevieria
Monocots – The Orchid Family (Orchidaceae)

Very large family with > 35,000 species,
especially abundant in tropics

Widely distributed with diverse habitats

Flowers exceptionally varied in size and form.

Many epiphytic on bark of trees.

Others aquatic or terrestrial and saprophytic.

Specific adaptations between orchid flowers and
pollinators are extraordinary and sometimes
bizarre.

Vanilla from vanilla orchid.
Monocots – The Orchid Family (Orchidaceae)

Three sepals and petals,
with one of petals (lip petal)
differing from other two

Stamens and pistil united in
single structure = column.
•

Anthers contain sacs of
pollen called pollinia.
Minute seeds produced in
prodigious numbers.
•
•
Each seed consists of only a
few cells.
Seed must become
associated with specific
mycorrhizal fungus to
germinate.
Review

Origin of Cultivated Plants

Selected Families of Flowering Plants
Dicots
Monocots
–
The Buttercup Family (Ranunculaceae)
–
The Grass Family (Poaceae)
–
The Laurel Family (Lauraceae)
–
The Lily Family (Liliaceae)
–
The Poppy Family (Papaveraceae)
–
The Orchid Family (Orchidaceae)
–
The Mustard Family (Brassicaceae)
–
The Rose Family (Rosaceae)
–
The Legume Family (Fabaceae)
–
The Spurge Family (Euphorbiaceae)
–
The Cactus Family (Cactaceae)
–
The Mint Family (Lamiaceae)
–
The Nightshade Family (Solanaceae)
–
The Carrot Family (Apiaceae)
–
The Pumpkin Family (Cucurbitaceae)
–
The Sunflower Family (Asteraceae)