This document summarizes the key adaptations that allow plants to survive in aquatic environments. It discusses the different types of aquatic plants including submerged, floating, and emergent plants. Submerged plants are completely underwater and have highly dissected leaves and no stomata. Floating plants either have roots fixed to the bottom or are free floating, and have spongy, buoyant tissues. Emergent plants have stems and leaves that emerge from the water but have underwater basal portions. A key adaptation is aerenchyma tissue, which forms air spaces that transport oxygen throughout the plant. These adaptations allow aquatic plants to exchange gases, absorb minerals, and produce food through photosynthesis in water.

1. Plant adaptation
to aquatic
Environment
Student name: Afsana Chowdhury
Student id: 20585101

2. What is Aquatic
Plants?
• Adapted to growing in or under water (salt
or fresh water)
• Hydrophytes or macrophytes.
• Serve an important job : Provide food and
oxygen for aquatic ecosystem.
• Needs special adaptive features to exchange
gases, reproduce, and for maintaining salt
and water balance.

3. What aquatic plants
need to survive?
• Sunlight - Use sunlight energy to carry out
photosynthesis
• Water and minerals – Need for growth.
• Gas exchange - Oxygen required for Supporting
cellular respiration and Carrying 𝑪𝑶 𝟐 for
photosynthesis.
• Movement of water and mineral
- Absorb water and mineral through their roots but
prepare food in leaves.
- Have to have specialized tissues for carrying water
to the leaves and distributed prepared food to other
part of the body.

4. How Aquatic Plants Produce Energy ?
• Needs oxygen to produce energy.
• Make their own food through
process of photosynthesis.
• Have chlorophyll that is needed
for photosynthesis.
• In the day light, plants use sun
energy, water and 𝑪𝑶 𝟐 to make
their own food.
• Plants release oxygen into the
water and aquatic animal use the
oxygen to breathe.

5. Aerenchyma tissue
• photosynthesis activity can be
curtailed at the cloudy days or at
murky water and turbidity.
• Evolved some strategies to solve
these problems.
• Aerenchyma tissue
• Spongy network of cell.
• Creates air space in plant.
• That air space act like a tunnel
which allowing plants in
transporting oxygen from the
surface to other parts of the plants.

6. Buoyancy ( how plants float?)
• Aerenchyma tissue also help in the
Buoyancy.
• The amount of gas in plant stem and
leaves act like flotation device
• Give them structure and support with
the absence of tough bark or wood
like the terrestrial plants

7. Types of Aquatic plants
• 3 types
• Submerged
plants
• Floating plants
-Free floating
plants
- Fixed aquatic
plants
• Emergent plants
Fig: Types of aquatic plants

8. Submerged plants
• They are completely submerged
in water
• The highly dissected leaf of plants
help for photosynthesis by
creating notable surface area.
• Presence of no stomata in the
leaves.
• Roots act like an anchor.
- main role is to absorb nutrient
from water.
• Example: Hydrilla, Pondweed
Fig : Hydrilla
Fig: Pondweed

9. Floating Plants
• Fibrous root system
• Some floating plants Roots
are fixed to the bottom and
some are not.
• Photosynthesis is
performed on the floating
leaves.
• They are light in weight
and spongy.
• Example: Water hyacinth,
Duckweed.
Fig: Water hyacinth
Fig : Duckweed

10. Free floating plants
• Roots are not connected
to the sediments.
• Floats freely on the water
surface.
• Leaves and stem has air-filled
cavities
• Cavities - Make them light in weight
-Help them to float in water
• Example: Water lettuce, water
hyacinth, Duckweed.
Fig : Water lettuce

11. Fixed aquatic plants
• Plants, which root is
connected to the
sediment.
• Stem with holes
• Leaves are broad
• Waxy coating on
leaves prevent rotting
• Example : Lotus and
waterlily
Fig: Water lily

12. Emergent Plants
• Their basal portion remains
under the surface of the water,
but stem and leaves can be seen
in the air.
• Narrow leaves, tall in height
• The hollow structure and presence
of hard fibers in the stem help the
plants surviving in winds
• Example: Reed, Wild rice etc.
Fig : Reed plants
Fig: Wild rice plants

13. At the end..
Aquatic plants increases oxygen
content of water and remove 𝑪𝑶 𝟐
from it, making the water suitable
for fish and other aquatic animals
and help them to get enough
oxygen.

14. References
• Beentje, Henk; Hickey, Michael; King, Clive (2001). "The Cambridge Illustrated Glossary of Botanical Terms".
Kew Bulletin. 56 (2): 505. doi:10.2307/4110976.
• Chambers, Patricia A. (September 1987). “Light and Nutrients in the control of aquatic plant Community
Structure. II. Insitu observations”. The journal of Ecology. 75(3): 621-628. Doi:10.2307/2260194. JSTOR
2260194.
• Pedersen, Ole; Colmer, Timothy David; Sand-Jensen, Kaj (2013). "Underwater Photosynthesis of Submerged
Plants–Recent Advances and Methods". Frontiers in Plant Science. doi:10.3389/fpls.2013.00140.
• Shtein, Ilana; Popper, Zoë A.; Harpaz-Saad, Smadar (2017). "Permanently open stomata of aquatic
angiosperms display modified cellulose crystallinity patterns". Plant Signaling & Behavior. 12 (7): e1339858.
doi:10.1080/15592324.2017.1339858.
• Vymazal, Jan (December 2013). "Emergent plants used in free water surface constructed wetlands: A
review". Ecological Engineering. 61: 582–592

15. That’s all…..
Thank
you