Download Plant phylogenetic tree

Plant phylogenetic tree
The life cycle of
a moss
Sphagnum, a
common
wetland moss
protoneme
Spongy rhizoid
tissue
http://images.google.ca/imgres?imgurl=http://kentsimmons.uwinnipeg.ca/2152/l8fig4.jpg&imgrefurl=http://kentsimmons.uwinnip
eg.ca/2152/lb8pg1.htm&h=664&w=600&sz=146&hl=en&start=2&tbnid=Jh_EsdcGnUOr6M:&tbnh=138&tbnw=125&prev=/imag
es%3Fq%3DSphagnum%2Blife%2Bcycle%26svnum%3D10%26hl%3Den%26lr%3D%26sa%3DN
antheridium
Antheridia clusters on the
leaf tips of gametophyte
archegonium
Parasitic
sporophyte
Fontilalis antipyretica
Habitat: Water moss is found attached to rocks or logs in swift flowing water, or floating loose or
attached to substrate in still water. It is common in shaded sites and prefers slightly acidic water.
It requires water below pH 8.4 where dissolved carbon dioxide is available.
Most ferns are homosporous—only one kind of spore and gametophyte
bears both sexes at different times
Fig. 29.23
Salvinia spp: a floating aquatic fern: aggressive weeds in shallow standing waters or slow
moving streams
Most species polyploid and sporangia are sterile
Reproduction: Salvinia molesta effectively reproduces through vegetative means. Stems fragment spontaneously
as plants mature. New branches develop from apical and lateral buds. Each node harbors up to five serial lateral
buds (Lemon and Posluszny 1997), adding to the high potential for growth and dormancy. Salvinia molesta will
withstand periods of stress, both low temperature and dewatering, through latent buds.
http://images.google.ca/imgres?imgurl=http://www.botgard.ucla.edu/html/botanytextbooks/lifeforms/images/aquaticplants/Salvinia1
.jpg&imgrefurl=http://www.botgard.ucla.edu/html/botanytextbooks/lifeforms/aquaticplants/a0042tx.html&h=239&w=360&sz=24&hl=en
&start=4&tbnid=Jm4d6m082X6MxM:&tbnh=80&tbnw=121&prev=/images%3Fq%3Daquatic%2Bfern%26svnum%3D10%26hl%3Den
%26lr%3D%26sa%3DG
Azolla, an aquatic fern used in rice culture
Is this plant homo- or
heterosporous?
Phylum Pterophyta—sporophytes are vascular
plants with megaphylls—ferns, horsetails, etc.
Phylum Pterophyta
The sphenophytes
Equisetum—the horsetail
•Upright jointed stems
growing from a rhizome
•Reproductive and
vegetative stems separate
Left—reproductive stems
bearing strobilae
Right—vegetative stems
Strobila of Equisetum with sporophylls
bearing sporangia
The life cycle
of Equisetum
A
homosporous
cycle
Isoetes, the quillwort
Heterospory
Some ferns
Quillwort
Seed plants
Advantages and disadvantages?
Trade-offs?
Homospory
Most ferns
Horsetails
http://www.cartage.org.lb/en/themes/sciences/BotanicalSciences/ClassificationPlants/Cryptogamia/Bryophyta
/NonvascularPlants/NonvascularPlants.htm
Life-cycle stages of a flowering plant
The anther is a
microsporangium, and
the pollen grain is a
microspore that
germinates to form the
male gametophyte (2
cells)
The megaspore is
inside the ovule, and
becomes an 8-celled
gametophyte
Fig. 30.13a
The
development of
angiosperm
gametophytes
Fig. 38.4
Common Cattail
Typha latifolia
Cattail family (Typhaceae)
Spike bearing staminate flowers
Each staminate flower bears 4 grains of pollen; its
petals and sepals are reduced to bristles. After the
pollen is released, the staminate spike quickly
withers away.
Spike or catkin carrying pistillate
flowers
fertile pistillate flower has a stipe at least 1 mm. long,
a single achene, and a single style with a flattened
stigma. The pistillate spike persists into the fall.
The blooming period occurs during early to midsummer. The root system produces thick starchy
rhizomes and fibrous roots. Colonies often grow and
expand vegetatively when new shoots are produced
from the starchy rhizome.
Typha latifolia
Scirpus microcarpus: panicled bulrush
http://www.tva.gov/river/landandshore/stabilization/plants/images/scirpus_americanus.jpg
http://cricket.biol.sc.edu/herb/SS/Scirpus_americanus1.jpg
Sagittaria latifolia, broad-leafed arrowhead
http://www.uwgb.edu/BIODIVERSITY/herbarium/wetland_plants
The white water lily Nymphaea
http://images.google.ca/imgres?imgurl=http://www.ontariowildflower.com/images/bulrushhardstem.jpg&imgrefurl=http://ww
w.ontariowildflower.com/lakes.htm&h=483&w=370&sz=11&hl=en&start=5&tbnid=fPRsJ194C3ZH3M:&tbnh=129&tbnw=99
&prev=/images%3Fq%3Dbulrush%2Bflower%26svnum%3D10%26hl%3Den%26lr%3D%26sa%3DG
Nuphar variegata: bull-head pond lily
http://www.uwgb.edu/BIODIVERSITY/herbarium/wetland_plants
The smartweed Polygonum
Common duckweed: Lemma minor
http://images.google.ca/imgres?imgurl=http://www.mobot.org/jwcross/duckweed/graphics/frog_in_duckweed.gif&imgrefurl=http://
www.mobot.org/jwcross/duckweed/duckweedcharms.htm&h=291&w=432&sz=122&hl=en&start=1&tbnid=SyVvY42awRVryM:&tbnh=85&tbnw=126&prev=/images%3Fq%3DD
uckweed%26svnum%3D10%26hl%3Den%26lr%3D%26sa%3DG
Floating leaved Pondweed, Potamogeton natans
Water milfoil, Myriophyllum exalbescens
Potamogeton filiformis
Potamogeton praelongus
http://images.google.ca/imgres?imgurl=http://www.uwgb.edu/BIODIVERSITY/herbarium/wetland_plants/potpra_FlowersAndFruit01gf
400.jpg&imgrefurl=http://www.uwgb.edu/BIODIVERSITY/herbarium/wetland_plants/potpra01.htm&h=400&w=224&sz=17&hl=en&star
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D10%26hl%3Den%26lr%3D%26sa%3DN
Vallisneria americana
http://www.uwgb.edu/BIODIVERSITY/herbarium/wetland_plants/valame_aspect01_web400gf.jpg
Vallisneria americana: a dioecious species, sexes on separate plants
Staminate plant
Flowers open at the water’s surface—wind pollinated
Pistillate plant
Also capable of asexual reproduction through vegetative “suckering”
Utricularia vulgaris: common bladderwort
http://www.uwgb.edu/BIODIVERSITY/herbarium/wetland_plants
Potamogeton richardsoni
http://www.uwgb.edu/BIODIVERSITY/herbarium/wetland_plants
Potamogeton amplifolius, big-leafed pondweed
http://www.uwgb.edu/BIODIVERSITY/herbarium/wetland_plants
Elodea canadensis
http://www.uwgb.edu/BIODIVERSITY/herbarium/wetland_plants
Ceratophyllum demersum: coonstail
http://www.uwgb.edu/BIODIVERSITY/herbarium/wetland_plants
Algae
•essentially weightless and lack supporting tissue
•no water or nutrient transport,
•Take up nutrients through the body surface from the surrounding water
•Use only holdfast cells for anchorage
•Most cells can photosynthesize and they have no need for stomates or an
impermeable cuticle
•Gametes swim through water
Terrestrial plants have gradually evolved
•roots for anchorage, water and nutrient uptake
•vascular tissue for water and nutrient transport, and tensile strength
•Leaves with concentrated photosynthetic tissue, a waxy cuticle and stomates to
regulate gas intake and water loss
•Mechanisms to protect gametes from drying,
•Pollination mechanisms to bring gametes together
With the exception of brypohytes which have always been heavily dependent on water
Most aquatic plants evolved from terrestrial plants and retain many of their features
•most have roots or rhizomes that take anchor the plant and take up nutrients
•most have true leaves, supplied by vascular tissue (veins)
•most reproduce sexually with flowers that produce pollen and seeds
•most have vasuclar tissue in their roots (or rhizomes) stems and leaves
Aquatic plants, escpecially the flowering plants, have evolved many modifications that
better adapt them for life in water.
•Reduction of xylem tissue—less need for support or water transport
•Increased flexibility, substituting tensile strength for rigidity
•Lacunate tissue—spongy air-filled tissue
•Tolerance of hypoxia—pumping O2 to rhizomes and tolerating elevated EtOH or lactate
•Thin or finely dissected leaves, to provide high surface/mass
•Stomata greatly reduced or absent, cuticle very much reduced
•Epidermis well supplied with chlorophyll
•Reduction in roots, since water uptake is not necessary, some lack roots or rhizomes
•Adaptive plasticity—different morphology depending on environment
•Flower reduction--pollination by wind or water, and rarely insects
•Fruit modification--spongy tissue (floating) for dispersal by water
•Increased reliance on vegetative propagation—fragmentation (winter buds) or suckering