Most massive =

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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).
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Welwitschia mirabilis Welwitschiaceae young
plant Note 2 strap-like leaves
http//waynesword.palomar.edu/images/welwit3b.gif
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As Welwitschia grows the 2 leaves split into many
sections. http//www.biosci.ohio-state.edu/plantb
io/images/greenhouseimages/welwitschia2.jpg
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Welwitschia is dioecious with separate male and
female plants.
Plant with female cones
Plant with male cones
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Welwitschia mirabilis can live for up to 2000
years by which time the two leaves have shredded
into multiple straps.
ttp//www.cactusandsucculent.org/riviste/2000/fasc
icolo-4/foto/welwitschia-mirabilis.jpg
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Courtesy of Amy Dieckmann 05
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Escalante National Monument, Ephedra in the
foreground
http//www.ut.blm.gov/monument/Science_and_Researc
h/pictures/ephedra.jpg
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Plant
Male strobili (cones)
Ephedra
Female strobilus (cone)
From Tree of Life Web Site, U. of AZ
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Gnetum, a woody plant with vessels
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Gnetophytes and Angiosperms have vessels.
a. Longitudinal tracheid of pine.
c. Hardwood fiber cell (provides support)
b. Vessel of a hardwood (early wood)
e. Trachied of a hardwood.
c. Vessel of a hardwood (late wood)
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Anthophyte Hypothesis
Gnetifer Hypothesis
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Two trees illustrating the Anthophyte vs Gnetifer
Hypotheses
Anthophytes
(Extinct)
(Extinct)
Gnetifers