Marine Flowering Plants
Marine flowering plants (MFP’s) are similar
to terrestrial (land) plants because they have
roots, stems and leaves, have xylem and
phloem tissues to transport nutrients up and
down the plant, and reproduce using flowers
and seeds!!! Some, the sea grasses, have
adapted to living totally submerged.
All MFP’s produce oxygen, take in CO2,
provide sediments controls for water ways,
and provide food, habitat and shelter for a
variety of organisms.
There are three types of Marine Flowering
Plants: sea grasses, salt marsh grasses, and
mangroves.
SEA GRASSES:
 Have roots, stems and leaves. Roots are
thickened into rope-like structures called
rhizomes which anchor the grasses on
the bottom.
 They grow totally submerged, found in
shallow waters in order to reach sunlight.
These are known as Submerged Aquatic
Vegetation, or SAV’s.
 Reproduce sexually by production of
seeds, and asexually by vegetative
reproduction – sending off runners or
shoots that develop roots and a new
plant.
 Have specialized cells called
aerenchyme which are air filled to
provide buoyancy (like the
pneumatocysts of the brown algae) to lift
the leaves of the plant toward the surface
and sunlight.
 Photosynthesis occurs primarily in the
leaves, xylem tissues transport minerals
from the roots throughout the plant,
phloem tissues transport sugars (the
product of photosynthesis) throughout
the plant.
 Salt marsh grasses form submerged
meadows which are grazed by
herbivores.
 Produce oxygen, take in CO2, provide
sediment control, provide food, shelter
and habitat for a variety of organisms.
 Examples include eel grass, turtle grass,
paddle grass and manatee grass.
SALT MARSH GRASSES:
 Have roots, stems and leaves. Are found
in shallow marshes bordering larger
bodies of water. Marsh grasses anchor
sediments, and filter runoff water as it
flows into the larger body of water.
Most of the marsh grasses structures are
above the water with only the roots and
lower stems below the surface.
 Reproduce sexually by flowers and
seeds, and asexually by vegetative
reproduction.
 Have specialized cells called salt glands
which remove excess salt taken in by the
plant.
 Marsh grasses concentrate salt around
the roots which promotes osmotic
movement of freshwater from the
surrounding waters into the roots.
 Have thick, waxy leaves which reduces
water loss due to transpiration.
 Provide habitat, food and shelter for
many organisms, including Maryland
terrapins, as well as many immature
species. Produce oxygen, and take in
CO2. They form lush green meadows in
shallow waterways.
 Examples include cordgrass, sawgrass,
and spartina grass.
MANGROVES:
 Hove roots, stems and leaves.
Mangroves have three specialized root
systems:
o Anchor root – large central root that
secures the mangrove deep into the
sediments.
o Stilt roots – stalk-like roots that raise
the main portion of the mangrove
above the water.
o Nutritive roots – surround the stilt
and anchor root and take in nutrients
from the soils and sediments
 These roots trap sediments extensively
which can result in island building
 Mangroves are either trees or shrubs
which grow only in warm, tropical
climates along shorelines and in shallow
waters.
 Reproduce sexually by flowers and
seeds. These specialized seeds are
called propagules. Propagules begin to
germinate before dropping from the
branches, therefore when they drop into
the sediments they have a head start on
growth. Propagules have a thickened
portion at the top of the seed and an
elongated “germinating” tap root
extending from the top. They can be
many inches long prior to dropping and
taking root in the bottom.
 Mangroves have thick, waxy leaves to
reduce water loss.
 Mangroves provide sediment control,
produce oxygen and take in CO2, and
provide habitat, food and shelter for
many organisms. They provide a
nursery environment for many smaller
and immature species and prevent
erosion of soils due to runoff.
 Examples include red mangroves, white
mangroves and black mangroves.