PLANT DIVERSITY 2
Plant Kingdom
Vascular
•
•
•
•
Bryophytes
seedless
Ferns
Gymnosperms
Angiosperms
Seed Plants:
-- Have seeds
-- Have pollen (containing sperm)
• PLANT KINGDOM (major groups)
Vascular
– MOSSES (“non-vascular”)
seedless
– FERNS
– GYMNOSPERMS (conifers)
– ANGIOSPERMS (flowering plants)
Seed Plants:
-- Have seeds
-- Have pollen (containing sperm)
Seed Plants Have:
• Vascular Tissue:
– Functions as in ferns
• Pollen: a structure that surrounds/contains sperm
– Allows transport of sperm without water
– Protects the sperm from drying out
– Adaptations to life on dry land, can reproduce w/o water
• SEEDS: a structure surrounding/containing the embryo
– Protects the embryo (from drying out)
– Provides food/nourishment for embryo
– Promotes dispersal of embryo away from established
plants—reduces competition
Pollen and Seeds are adaptations to dry land or help
increase reproductive success.
Pine Trees & firs are Gymnosperms
(specifically conifers)
Other Gymnosperms (specifically conifers):
Junipers (cypress and cedars)
Cycads are Gymnosperms too
And Ginko Trees
Gnetophytes including Ephedra are
also Gymnosperms
Gymnosperm Characteristics
• Vascular Tissue and Roots
• can grow large and in relatively dry places
• POLLEN:
– Allows fertilization/reproduction and
dispersal without water
• SEEDS:
– protects the embryo from drying until it
can germinate and promotes dispersal
We will look closer at pine trees as
examples of typical gymnosperms
Pine Trees have……
male cones
Needles
(leafs)
Cones
Female cone
--reproductive
structures
Reproduction, Pollen, and Seeds in Pines
• Male Cones make pollen
• Pollen is dispersed by wind
wings
Reproduction, Pollen, and Seeds in Pines
• Female cones make ovules containing the egg
scales
ovule
Reproduction, Pollen, and Seeds in Pines
• Ovule w/ egg turns into seed after fertilization
• Pine seeds have wings and are wind dispersed
Wings on pine
seeds
What is an Angiosperm?
A plant with flowers
...even when the flowers aren’t obvious
Angiosperms with non-showy flowers are
typically wind pollinated so large colorful
flowers are not needed to attract pollinators
and would get in way of wind
Conspicuous flowers use animal pollinators:
the key to Angiosperm success
Angiosperm Characteristics
• Vascular Tissue
– Can grow large and in relatively dry places
• Pollen
– Frequently dispersed by animals—pollinators
– But also wind (and occasionally water dispersed)
• Seeds
– Surrounded by fruit  promotes dispersal of embryo
• FLOWERS
– Attract pollinators (color & scent)
– Reward pollinators (nectar & pollen)
– Put sex parts in same place to promote pollinations/fertilization
• FRUIT—structure that surrounds the seed
– Can provide protection to seed
– Disperses the seed (MAIN IDEA BEHIND BENEFIT OF FRUIT)
• Frequently utilizes animals
• Sweet, fragrant, colorful
• Dry and “clingy”
– But also wind (and occasionally water dispersed)
Angiosperm pollen
• Made by anthers, allows sperm to travel to egg w/o water
Sperm nuclei and pollen tube
Fruit With Seed
• After fertilization:
• Ovule  seed
• Ovary of flower  fruit
Fruit with seed
Dry Fruit
Fruit v. Vegetable
Tomato:
fruit or vegetable?
…….would you put it in a fruit salad?
Tomato:
fruit or vegetable
• Botanically it is a fruit
• Typically used as a vegetable for cooking/culinary purposes
• US Supreme court decided that the tomato shall be considered a
vegetable in Nix v. Hedden (1893) for Tariff Act of 1883
• The 1887 a case came before the supreme court.
• John Nix sued the collector of port of New York to recover duty (tax)
paid on imported vegetables, but they argued they should not have
paid because the tomato is a fruit
• The U.S. Supreme Court decided on May 10, 1893 that the tomato
is a vegetable, based on them generally being served with dinner as
was typical for vegetables where as fruit were often used as
desserts and not part of main course.
• the court did not purport to reclassify the tomato for botanical or
other purpose
Flowers:
structure and function
Floral Parts:
• Sepals
• Petals
• Stamen/anthers: (produce pollen w/ sperm)
• Pistil (carpel): ovary (containing egg)
Additional Terms
• Dioecious: separate
male and female
individuals/plants
(organisms)
• Monecious: male
and female parts on
same individual plants
(organism)
Dicots v. Monocot
Monocot
• Seed
– One part/cotyledon
• Leaves
– parallel venation
• Flower parts
– Petals in multiples of
three
Dicot
• Seed
– two parts/cotyledons
• Leaves
– netted venation
• Flower parts
– Petals in 4’s or 5’s
Embryos
Leaf venation
One
cotyledon
Veins usually
parallel
Stems
Roots
Pollen
Flowers
Pollen grain
with one
opening
Floral organs
usually in
multiples
of three
Taproot
Pollen grain
(main root)
with three
usually present
openings
Floral organs
usually in
multiples of
four or five
Monocot
Characteristics
Root system
Vascular tissue usually fibrous
scattered
(no main root)
Eudicot
Characteristics
Vascular tissue
Two
Veins usually usually arranged
cotyledons
netlike
in ring