Download Gymnosperms

Seed-bearing Plants fall into two
major categories
Angiosperms
Gymnosperms
Seed-bearing Vascular Plants fall
into two major categories
• Gymnosperms –
seeds naked on
surface of cone
scale
• Angiosperms –
seeds enclosed in
a ripened ovary
and flowers are
produced
GYMNOSPERM CHARACTERISTICS
• From Greek words gymnos (naked) and
sperma (seed)
• Both Male and Female cones
Land Plants
Bryophytes
Pteridophytes
Angiosperms
Gymnosperms
Pteridophyte
Bryophytes
Seed-bearing plants
also produce pollen
Five Living Seed Plant Phyla
• Cycadophyta
• Ginkgophyta
Gymnosperms
• Pinophyta or
Coniferophyta
• Gnetophyta
Angiosperms • Anthophyta
Living Gymnosperm Phyla
Conifers Pinophyta or
Coniferophyta
Cycadophyta Cycads
Ginkgophyta Ginkgos
Gnetophyta Gnetophytes
Conifers – the most conspicuous
and common gymnosperms
Conifers
About 70 genera with
about 630 species
Conifers
• Conifers are well represented in the fossil record
Sequoia affinis
Conifers are of great
ecological importance
• Conifers are the dominant
members of the vast
Boreal forests (Taiga)
Conifers are of great
ecological importance
• Conifers are very important members of
many types of ecosystems
Conifers are of great
economic importance
• Edible Seeds
• Crates, Boxes,
Matchsticks,
Furniture
• Telephone Poles
• Turpentine and
Rosin (Resin)
• Fuel (Pitch)
• Pulpwood
• Ornamentals
• Pharmaceuticals
(Taxol)
There are Seven
Living Families of
Conifers
Pinaceae - Pine family
Araucariaceae - Araucaria family
Podocarpaceae - Yellow-wood family
Sciadopityaceae - Umbrella-pine family
Cupressaceae - Cypress family
Cephalotaxaceae - Plum-yew family
Taxaceae - Yew family
Five of the Most Familiar
Groups of Conifers
Norfolk Island
Pines
Pines, Firs, Spruces
Sequoias and
Redwoods
Junipers and
Cedars
Yews
The Largest, Tallest,
and the Oldest Plants
are Conifers.
All found in California
• Giant Sequoias of the
California Sierras are
the largest
• Coastal Redwoods are
the tallest
• Bristlecone pines of
the California White
Mountains are the
oldest
Pines - genus Pinus of the
family Pinaceae
• Most familiar of all conifers
• About 90 species
Vegetative Characters of Pine
Pine Stems
• Extensive branching
• Christmas tree shape
• Very woody
Pine Leaves
• Needles
produced in
clusters
(fascicles)
of 1 to 5
Pine – Reproductive Structures
Pines produce pollen and seeds
in cones
Pines are Monecious
Individual plants produce both pollen cones and
seed cones
Seed Cone
C
Pines are Monecious
Individual plants produce both pollen cones and
seed cones
Pollen Cone
C
Pollen cones produce pollen
C
Pine Pollen
• Wind pollination is facilitated by
pollen morphology.
Ovulate or Seed Cones
Produce Seeds
Young seed cone
Cone scale
C
Mature seed cone
Conifer Seed reminder
Conifer
Cones
Yew (aril)
Pine
Giant Sequoia
Juniper
Bald Cypress
Conifer Leaves
Map of Living and Fossil Members of
Taxodiaceae (Redwood Family)
Dawn Redwood Metasequoia glyptostroboides
and Coastal Redwood Sequoia sempervirens
Cycadophyta
the Cycads
Cycads Appeared
on Earth
250 MYA
• Greatest
abundance and
diversity during the
Jurassic
• Declined sharply
during the
Cretaceous
radiation of the
angiosperms.
Cycad seeds are toxic to humans
•
•
•
•
Cyanobacteria in roots of cycads
Flying foxes eat neurotoxic cycad seeds
Humans eat the flying foxes
Humans get sick (neurological disorders)
Cycads
Australian
Mexican
African
Only Cycad Native to the US
In Florida
Zamia integrifolia
Host Plant for
Atala Butterfly
Cycads contain cycasin, a toxic
secondary plant chemical. Cycads
are toxic to humans, dogs and
livestock. Cycasin is found in the
atala butterfly and other
organisms find it distasteful and
avoid eating it.
Gymnosperms
Cycads
Conifers
Ginkgos
Bryophytes
Pteridophytes