In free-sporing tracheophytes, the dispersal unit is the spore (e.g., Dryopteris spore above), which germinates into a gametophyte-- so the haploid stage is dispersed for these plants.

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In free-sporing tracheophytes, the dispersal unit
is the spore (e.g., Dryopteris spore above),
which germinates into a gametophyte-- so the
haploid stage is dispersed for these plants.
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In the seed plants the sporophyte (embryo) is
dispersed. So the diploid stage is dispersed for
seed plants as in this rice seed above.
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In this seed (Capsella sp.), note the three main
parts of the embryo The epicotyl will become
all of the above ground parts of the plant. The
hypocotyl will form the transition zone between
the roots and the stem, and the radicle will
form all of the below ground parts of the plant.
http//www.uwinnipeg.ca/simmons/images/embryo3.gi
f
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Coconut Fruit (a drupea fleshy indehiscent fruit
with a seed enclosed in a stony endocarp) with
its single seed in the center. Peaches and
cherries are also drupes. www.botany.hawaii.edu/fa
culty/webb/BOT410/Angiosperm/CoconutDrawFruitsLab.
jpgimgrefurlhttp//www.botany.hawaii.edu/faculty
/webb/BOT410/Angiosperm/FruitCoconut.htm
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Tissue from the megagametophyte
Root End
Cotyledons
Naked seed e.g in this dissected Pinus sp.
seed, note young sporophyte.
http//botit.botany.wisc.edu/courses/Botany_130/Di
v/Phyla/Coniferophyta/Gymnosperm/Embryo.html
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www.pioneer-net.com/psr/wallpaper.html
www.prairiepoint.net/journal/images/P7200015.jpg
Seeds Are Diverse
http//natureproducts.net/Forest_Products/Trees/St
erculia20brevissima20seeds.jpg
http//project.bio.iastate.edu/trees/campustrees/A
cerSaccharu/AcerSacc_fruit.html
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Equisetum and Psilotum are in the fern clade.
(Pryer et al. 2001. Nature
409618-622.)
Leptosporangiate Ferns
Ferns and Fern Allies
True Leaved Plants
Seed Plants
Lycopods
Mosses
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CYCADS The basic growth form of a cycad is a
central trunk with leaves spirally arranged
at the top.
http//www.damer.com/pictures/travels/southafrica/
transvaal2.jpg
helios.bto.ed.ac.uk/bto/microbes/nitrogen.htm
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Cycads are dioecious and heterosporous
Male Cone
Cycas revoluta is dioecious
Female Cone
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The megasporophylls for Cycas is leaf-like with
ovules at the base.
The enlarged one has been fertilized and is
developing into a seed
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Male cones are also simple with each
microsporophyll a modified leaf (forming a
stalked peltate structure).
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In Zamia the megasporophyll is highly reduced to
a stalked, peltate-like structure. They are
organized into a simple cone.
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Cycadaceae
Male cone and Cataphylls (a synapomorphy) of
Cycas taitungensis (native to Taiwan)
www.pacsoa.org.au/cycads/Cycas/taitungcone.jpg
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Cycad Coralloid Roots (a synapomorphy of
cycads) These roots grow up rather than down and
can be seen above ground. They have symbiotic
blue-green algae (see next slide)
www.botany.hawaii.edu/.../LabsHTML-99/
Roots/LABROT12.jpg
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Coralloid roots in Cycads
Cross-section of coralloid root showing layer of
blue-green algae (a nitrogen fixer).
(Dioon
spinulosum) Image from Waynes World
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Ginkgo biloba -Maidenhair Tree Ginkgoaceae Note
the dimorphic shoots-- short spur shoots and the
long shoots bhort.bh.cornell.edu/conservatory/
gingko.jpg
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Ginkgo Male Cone
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Ginkgo ovules
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Ginko sperm Multiflagellated Anterior position of
flagella
Pollination droplet on Ginkgo ovule. The droplet
is repeatedly exuded and retracted.
http//tokyocinema.net/E-ginkgo.htm
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www.salisbury.edu/arboretum/ Ginkgo/GiBi/photos/Gi
BiSD01.JPG
Ginkgos are widely planted in urban areas because
they are resistant to pollution. They also have
deciduous leaves that turn yellow before they
drop. The fruits have an outer soft layer that
has a powerful sewer-like smell. http//images.goo
gle.com/imgres?imgurlana.sote.hu/Gingko.jpg
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www.ucmp.berkeley.edu/seedplants/ginkgoales/ovules
nleavessm2.jpg
http//www.kikkoman.com/contents/cookbook/cook_img
/G2.gif
Once the outer soft layer and the hard layer are
removed, the inner part of the Ginkgo seed can be
eaten.
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Pine Life Cycle - Monoecious, Heterosporous
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Sporophyte, Monoecious
simple male cone
Scales have microsporangia on lower surface
compound female cone
Cells in the microsporangium undergo meiosis to
form microspores (Pollen grains)
Cone scales have 2 ovules on the upper surface.
Microspores germinate into a male
gametophyte
One cell(megaspore mother cell) in the ovule
undergoes meiosis. One meiotic
product (haploid) survives. This is the
megaspore.
The megaspore develops into the female gametophyte
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Pine Ovule sits on top of a cone scale and is a
mix of sporophytic and gametophytic tissues
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Pollen (microspore) lands on the ovule and
germinates into a male gametophyte (pollen tube
and associated cells) which carries the gametes
to the archegonia which contains the egg.
Pine ovule
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Evolution of the female cone in the Pinaceae
Cordaites extinct
Lebachia extinct
Pinus
The ovule flips forward and the shoot, scales and
bract fuse to form the cone scale.
Dwarf shoots (d s) with ovules (o) and sterile
scales (ss) all subtended by a bract (br).
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Our focus is on 3 ( )of the 7 conifer (cone
bearing) families
Conifer Families
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Pinaceae

• Pinus
• Picea
• Larix
• Abies
• Tsuga

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www.wisc.edu/botit/img/bot/130/Gymnosperms/Conifer
ophyta2520Images/Pinus2520Images/Microsporangiat
e/pine2520pollen2520MC.jpg
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Male cones are Simple.
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Female cones are complex
Pinus sp.
The winged seed and the ovule opening towards
the cone axis are both synapomorphies. The wing
is derived from scale tissue.
http//www.zoobotanica.u-net.com/GIF20files/Botan
ical/pine.GIF
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Close up of 2 ovules which open towards the
cone axis (a synapomorphy)
X-section of young female pine cone
www.science.siu.edu/landplants/Coniferophyta/image
s/Pinus.female.cone.Sect.JPEG
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Pine pollen (Microspore) NoteThe wings are
Actually air bladders which may facilitate wind
dispersal or the pollination process itself.
Tube nucleus Generative nucleus (will divide to
form 2 sperm nuclei)
www.wisc.edu/.../Microsporangiate/
pine20pollen20MC.jpg
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Pine pollen grains viewed with fluorescent
microscopy. You can see the bladders (wings)
more easily than under conventional microscopy.
micro.magnet.fsu.edu/.../gallery/ pinetreepollen.h
tml
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Range map in N.Am. Picea, the genus, is
circumboreal and occurs as a co-dominant with
firs (Abies spp.) in vast expanses of spruce-fir
forests.
Picea glauca White Spruce Pinaceae There are
35-40 species of Picea worldwide. Half are in
China
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Picea rubens Red spruce Pinaceae P. rubens is our
Eastern species. It has small hairs on its
branches. Its range extends south along the tops
of the Appalachians. Locally it occurs on top of
Mt. Greylock and the Dome.
Range Map- note eastern distribution
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Picea abies Norway Spruce Pinaceae An introduced
European spruce widely planted on campus. Note
large cones, upward sweeping branches and and
droopy branchlets. Its profile desingates it as
a 60mph species!
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Abies balsamea Balsam Fir Pinaceae Note Upright
cones with deciduous cone scales leaving upright
candles and triangular profile.
Range Map showing eastern distribution. Note
there are 40 species of Abies worldwide (9 in the
US).
http//wiscinfo.doit.wisc.edu/herbarium/photos/ABI
BAL_KKOHOUT.jpg
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Larix laricina Larch Pinaceae Larix laricina is
our only deciduous conifer. It has dimorphic
shoots-- long and spur shoots.
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Tsuga canadensis Hemlock Pinaceae Note droopy
top (a 60mph characteristic), small
hanging cones, row of leaves parallel to the
stem axis.
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Cupressaceae

• Thuja
• Juniperus

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Juniperus communis, Common Juniper, Cupressaceae,
female plant Junipers are dioecious.
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Juniperus communis Common juniper Cupressaceae Con
es are made up of 3 fleshy scales which give the
appearance of a berry!
Leaves are awl-shaped with a single white
stripe of stomates in the center.
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Juniperus virginiana, Eastern Red Cedar,
Cupressaceae, http//www.csdl.tamu.edu/FLORA/mi06/
mi06012.jpg
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Juniperus virginiana showing scale-like leaves
that are 4-ranked, developing fruits (mature
fruits are blue).
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Close up of branch showing leaf arrangement in
4s-- 2 on each side, one in the middle, and one
behind.
Range map in N.Am.
Thuja occidentalis, Northern White Cedar,
Cupressaceae
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Thuja occidentalis White Cedar Cupressaceae
Note scale-like leaves and flattened Branches.
Leaves also have glands (not visible).
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Thuja occidentalis White Cedar Cupressaceae
Old cones
Young cones
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Taxaceae

• Taxus

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Seeds of Taxus are enclosed in a fleshy aril (an
outgrowth of the stem below).
Taxus canadensis Yew
Leaves are arranged spirally around the stem but
appear 2-ranked. Petioles and the underside of
the leaves are yellow.
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The conifers have the
Most massive Giant Sequoias Sequoiadendron
giganteum (Cupressaceae) ...
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..The Tallest Coastal Redwood (Sequoia
sempervirens) (Cupressaceae) .
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.. And the oldest Bristlecone Pine Pinus
longaeva (Pinaceae).