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on the tables where the microscopes are.
Thanks!
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pick one up from the front desk.
Gymnosperms
(non-flowering seed plants)
EKU BIO 131
Gymnosperms
• Phylum Ginkgophyta
Ginkgo – the only species is Ginkgo biloba
• Phylum Cycadophyta
the cycads
• Phylum Coniferophyta (or Pinophyta)
the conifers
• Phylum Gnetophyta
the gnetophytes
Ginkgo
ovule and seed development
Ginkgophyta
microsporangia
on male tree
Leaves and seeds
ripe seeds
cleaned seeds (sometimes
called “Ginkgo nuts”)
germinating seeds
Cycadophyta sporophytes
Two explorers with the only wild
specimen of Encephalartos woodii ever
discovered. It was first discovered
in the early 1700s.
Cycad cones
seed cones
pollen cones
Encephalartos
woodii
Cycad sporangia and coralloid roots
note microsporangium,
tapetum, microspores
coralloid roots
note integuments, megasporangium,
Female gametophyte
root with zone of symbiotic cyanobacteria
Coniferophyta
Pollen cone buds of Japanese Black Pine
(at about meiosis time)
pollen cone
buds
(the dark spots
are the tips of
the microsporophylls)
buds containing
needles
photo by Ross Clark
Coniferophyta
Pine pollen development
be able to identify all structures
Pine ovule development
be able to identify all structures
Coniferophyta
Gnetophyta:
Gnetum
notice stamens and ovules
(plant is monoecious)
seeds
Gnetophyta: Ephedra
female
male
seeds
(Ephedra is dioecious.)
Ephedrine is
potentially
dangerous.
Gnetophyta:
Welwitschia
Welwitschia is definitely one of the world’s most unusual plants!
Here is Welwitschia’s
only habitat: the
Namibian Desert, one
of the driest deserts in
the world.
Welwitschia is one of
The world’s rarest
plants. Most of the
following photos were
taken by Terry Huff,
an EKU graduate
student.
photo by Terry Huff
Gnetophyta:
Welwitschia
Welwitschia has two leaves. They have basal meristems. The leaves eventually
become separated into tattered segments.
Welwitschia is dioecious. This is a
female plant. Note the ovulate (seed)
cones, and compare them with the
pollen cones on the next slide.
photo by Terry Huff
Here is a young plant. Young plants are extremely rare.
Note the two leaves.
photo by Terry Huff
Gnetophyta:
Welwitschia
photo by Terry Huff
Here is a male plant.
Note the smaller pollen cones.
photo by Terry Huff
Gnetophyta:
Welwitschia
photo by Terry Huff
Here are some female (seed)
cones, together with the small
bugs that live on Welwitschia
and may help to pollinate it.
photo by Terry Huff
photo by Terry Huff
Gnetophyta:
Welwitschia
photo by Terry Huff
Here are some female cones,
together with the small bugs
that live on Welwitschia and
may help to pollinate it.
photo by Terry Huff
photo by Terry Huff
Here are some very young seed cones,
at about pollination time.
Gnetophyta:
Welwitschia
photo by Terry Huff
Here is another nice photo
of a plant loaded with seed
cones. Very few of the seeds
germinate, because of the
extreme environmental
conditions in the Namibian
Desert.
photo by Terry Huff
photo by Terry Huff
Why so many photos of Welwitschia?
-- because these photos by Terry Huff are some of the best photos ever
taken of Welwitschia in its native habitat. They are better than any other
photos you will find in any textbooks or on the web.
Terry said he was told there were fewer than 20 Welwitschia plants
remaining in their native habitat.