Spore Shedding Vascular Plants

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Spore Shedding Vascular Plants

• Psilotum
• Lycopodium
• Equisetum

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Psilotum nudum (whisk fern)
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Psilotum nudum (whisk fern)
http//imagenes.infojardin.com/sube/images/cqs1194
212302m.jpg
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Psilotum has a stem doing virtually all the
photosynthesis, with dichotomous branching,
enations without vascular tissue, and yellow
synangia in the axils of the enations. Below
ground, the stem is not photosynthetic but the
epidermis forms rhizoids for anchorage. The plant
thus lacks roots and leaves with underground stem
(rhizome) doing the anchorage functions.
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Psilotum stem cross section
radial
exarch
triarch
actinostele
cutin
guard cells
epidermis
PSN cortex
lignified cortex
respiring cortex
phloem
metaxylem
protoxylem
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Protosteles
haplosteles
actinostele
plectostele
cortex phloem xylem
siphonostele
solenostele
dictyostele
cortex phloem xylem pith
leaf gap
leaf trace
eustele
atactostele
dicot stem
monocot stem
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Psilotum stem specimen more than triarch
http//sols.unlv.edu/Schulte/Anatomy/Stems/Psilotu
mWhole.jpg
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Psilotum rhizomes with rhizoids
http//upload.wikimedia.org/wikipedia/commons/thum
b/3/3b/Psilotum_nudum_Rhizome.jpg/800px-Psilotum_n
udum_Rhizome.jpg
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Psilotum rhizome cross-section
http//www.dipbot.unict.it/sistematica_es/Immagini
/21001.JPG
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Psilotum stem demonstrates dichotomous branching,
enations (no vascular tissue) and two of the
three sporangia in a single synangium
http//www.dipbot.unict.it/sistematica_es/Immagini
/21001.JPG
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Psilotum sporangium (a three-parted
synangium) This specimen has shed its spores into
the wind and so the sterile jackets are empty. At
the bottom of the view is a partial stem
cross-section showing epidermis, cortex and a
portion of the vascular cylinder.
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http//kentsimmons.uwinnipeg.ca/2153/Psilotum_game
tophyte.jpg
antheridia
http//www.siu.edu/perspect/01_sp/pics/psilotum.j
pg
Psilotum gametophyte tissues all haploid
http//kentsimmons.uwinnipeg.ca/2153/psilotAnthLow
Mag.jpg
archegonium
http//kentsimmons.uwinnipeg.ca/2153/psilotoArchig
onium.jpg
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Psilotum gametophyte (SW to NE) and sporophyte
(Y-shape)
1N antheridium
2N rhizome
2N rhizoid
1N rhizoid
1N gametophyte
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Rhynia
Cooksonia
Earliest Land Plants from the Early Devonian
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Huperzia a forest wetlands dwelling
lycophyte These plants are the diploid sporophyte
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Huperzia lucidula a wetlands-dwelling lycophyte
http//www.duke.edu/jspippen/plants/lycopodium-lu
cidulum060727-3857bchmtnz.jpg
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Huperzia root cross-section
epidermis
cortex
protoxylem
xylem
metaxylem
phloem
plectostele
exarch
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microphyll
stem
sporophyll
sporangium
spores
gemma
http//home.manhattan.edu/frances.cardillo/plants
/vascular/lucidum6.jpg
last years sporophylls
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Huperzia root cross-section with branch root
cross sections
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Lycopodium microphyll cross section
mesophyll
cutinized epidermis
vascular bundle
stoma
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Lycopodium obscurum a forest-dwelling lycophyte
The sporophylls are organized into a terminal
strobilus.
http//www.twofrog.com/images/groundpine58.jpg
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Lycopodium obscurum sporophytes demonstrate
dichotomous branching. Microphylls are spirally
arranged with some flattening of the branch
system.
Lycopodium obscurum strobili are not interrupted
by microphylls. Sporophylls are not
photo-synthetic.
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Strobilus Longisection
sporophyll
sterile jacket
spores (1N)
sporangium
stalk
All the spores are the same small size, so
Lycopodium is homosporous. The spores are shed
into the wind.
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Lycopodium gametophytes may be photosynthetic
http//www.cas.vanderbilt.edu/bioimages/l/wlyal5-g
amicro16920.JPG
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The sperm is flagellated and chemotactic
http//www.botany.hawaii.edu/faculty/webb/bot311/b
ot311-00/LycoRepro/Lycopodium_sperm.jpg
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Diphasiastrum complanatum a forest-dwelling
lycophyte
http//www.duke.edu/jspippen/plants/lycopodium-di
gitatum060709-8672alamancez.jpg
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Lycopodiella alopecuroides a grassland dwelling
lycophyte
http//128.253.177.181/users/robbin/9_7_05/upload9
0/Lycopodiella_X_gilmanii_ME48.JPG
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Lycopodium innundatum a bog-dwelling lycophyte
http//farm2.static.flickr.com/1270/1048564007_47a
cf0621a.jpg?v0
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Rhynia was a Psilotum-like swamp dwelling
organism living with Protolepidodendron, the
herbaceous ancestor of woody Lepidodendron in
swamps during the Devonian period.
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Lepidodendron was a large lycophyte tree living
in marshes. Dead plants and spores built up in
the peat of the marshes, were later overrun with
sediments, and by heat and pressure were
converted to coal.
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Equisetum hyemale the perennial (evergreen)
horsetail
http//www.sbs.utexas.edu/bio406d/images/pics/equ/
Equisetum20hyemale20habit1.jpg
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Equisetum hyemale produces strobili at the end of
the stem. The stem does all of the
photosynthesis. Below ground are rhizomes and
roots. Note how the strobili open to shed spores.
http//www.missouriplants.com/Ferns/Equisetum_hyme
nale_plant.jpg
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Equisetum hyemale leaves are whorled microphylls
The microphylls are fused laterally and extend
over the internode above. Lateral branches appear
from lateral buds at the axils of the
microphylls, but puncture through the fused
microphylls. The stem surface is loaded with
silicates giving these plants their other common
name scouring rush.
http//www.missouriplants.com/Ferns/Equisetum_hyme
nale_stems.jpg
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Equisetum hyemale stem cross section
epidermis stomata and hypodermis with silicates
photosyn-thetic cortex
hollow pith region
ring of vascular bundles
air canal
http//botit.botany.wisc.edu/courses/img/bot/401/S
phenophyta_(Arthrophyta)/Equisetum/Equisetum/Stem
20Cross20Section20MC20.jpg
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protoxylem
endarch
radial
xylem phloem xylem
http//protist.biology.washington.edu/Biol441/Lab
20Images/CIMG0829.jpg
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Equisetum arvense the annual horsetail
http//bellquel.bo.cnr.it/scuole/serpieri/erbario/
immagini20erbacee20spontanee/Equisetacee/Equiset
um20arvense202.jpg
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Equisetum arvense stems also do all of the
photosynthesis, and the microphylls are whorled
and fused as well. The annual scouring rush does
much of its photosynthesis in the lateral branch
stems that develop from each microphyll
axil. This is the plant that looks most like a
horse tail.
http//k43.pbase.com/u26/elsnab/upload/43254952.18
1_8187_RJ_small.jpg
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Pink E. arvense fertile shoots emerge in early
spring
http//www.chirinka.com/catalog/images/equisetum2
0arvense.jpg
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Each strobilus scale has a central stalk and
several sporangia hanging beneath it.
sporangia
sporangiophore
sporangiophore cap
spores
http//www1.fccj.edu/dbyres/David/equi40.jpg
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The sporangiophore elongates to open the
strobilus. The sporangia open and shed
spores. Elaters help the spores push-off each
other.
http//www.msrosenthal.com/Ferns/images/New_Jersey
_and_New_York_Images/Equisetum_arvense1.jpg
http//www.essencesonline.com/Horsetail-big.jpg
http//www.snv.jussieu.fr/bmedia/mouvements/img-ph
oto/equi854.jpg
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The Equisetum gametophyte growing from a spore is
autotrophic and similar to a thallose liverwort
in form
http//www.cas.vanderbilt.edu/bioimages/biohires/e
/heqhya-gadw431.jpg
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Antheridia on the gametophyte thallus shed
multiflagellate sperm
http//www.cavehill.uwi.edu/FPAS/bcs/bl14apl/Equis
etum_arv_sperm.JPEG
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Archegonia on the gametophyte produce an
egg. After syngamy, the zygote grows into a young
sporophyte.
http//www.puc.edu/Faculty/Gilbert_Muth/phot0160.j
pg
44
Play here, the movie clips from the files on the
hard drive.
http//www.iwf.de/iwf/do/mkat/listing.aspx?Action
QuicklinkSearchprothalliumSearchInKeywords
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Calamites swamp forest (30 ft tall)
http//www.arcadiastreet.com/cgvistas/images/earth
_calamites__dreps_600.jpg
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Equisetum giganteum growing in Chile can grow to
be fairly tallperhaps 20 feet. Without wood,
that is still amazing for an herbaceous plant.
http//w3.fiu.edu/husby/Chad20with20Equisetum20
Lluta20valley.jpg
http//www.fiu.edu/chusb001/GiantEquisetum/Images
/NorthernChile/LlutaConingSessile.html