1. Morphological, Anatomical & Physiological Adaptations of Hydrophytes
Aarif Maqbool Department of Botany
Govt. Degree College
Bijbehara

2. Learning Objectives: What is adaptation?
Plant groups based on adaptations.
Hydrophytes
Classification of Hydrophytes
Adaptations of Hydrophytes
Morphological Adaptations of Hydrophytes
Anatomical Adaptations of Hydrophytes
Physiological Adaptations of Hydrophytes

3. What is an Adaptation?
Any feature of an organism or its part which enables it to exist under conditions of its habitat is called adaptation.
Adaptations are for:
Withstand adverse conditions of an environment.
Utilize maximum benefit of environment.

4. Plant groups based on adaptations
Classification of plants:
On the basis of their water requirement, Warming (1909) primarily recognized three major groups of Plants.
Hydrophytes: Plants which live in water.
Xerophytes: Plants that live in conditions where water is scare.
Mesophytes: Land plants living in environment with moderate amount of moisture.

5. Hydrophytes: Free floating hydrophytes Submerged floating hydrophytes
Hydrophytes are plants that grow in regions, where, there is plenty of water supply or wet soils.
The hydrophytes are generally classified into the following five categories:
Free floating hydrophytes
Submerged floating hydrophytes
Rooted submerged hydrophytes
Rooted hydrophytes with floating leaves
Rooted emergent hydrophytes

6. Free floating hydrophytes: They float freely on the surface of water. e.g., Eichornia, Pistia, Wolffia, and Lemna)
Eichornia
Wolfia
Lemna

7. Submerged floating hydrophytes: These are the plants in contact with only water, being completely submerged & not rooted in mud e.g., Utricularia, Ceratophyllum, Najas, etc.
Najas
Ceratophyllum

8. Rooted submerged hydrophytes: They are submerged in the water but roots are fixed. E.g., Hydrilla, Vallisneria, Potamogeton.
Hydrilla
Vallisneria
Potamogeton

9. Rooted hydrophytes with floating leaves: The roots of the plants are fixed in the soil while leaves are floating on the surface of water. E.g., Nymphaea, Victoria, Trapa.
Nymphaea
Victoria
Trapa

10. Rooted emergent hydrophytes: They grow in marshy areas
Rooted emergent hydrophytes: They grow in marshy areas. Plants that partly in water and partly in air. E.g., Ranunculus, Sagitaria, Typha.
Typha
Sagitaria
Ranunculus

11. Adaptations of Hydrophytes:
Morphological Adaptations
Anatomical Adaptations
Physiological Adaptations

12. Morphological Adaptations of Hydrophytes:
Roots:
Poorly developed or absent in plants
like Wolfia, Ceratophyllum.
Root hairs are absent in certain plants.
Root caps are replaced by root pockets(Eichornia, pistia).
The roots act as a balancing and anchoring organs.
Aerial roots are developed in certain plants like Jussiaea.

13. Stem: It is long, slender & thin. It is green in color so carry
out photosynthesis.
In some floating forms stem
is spongy (Eicchornia).
Stem helps in reproduction by stolons and offsets.
Stem is a rhizome in rooted plants with free floating leaves E.g.,: Nymphaea and Nelumbo.

14. Leaves: are deposited with wax
•In many floating forms leaves
are deposited with wax
(Nymphaea,Victoria regia). •In submerged forms they are
reduced and thin. •In emergent hydrophytes leaves
are of two types dissected leaves
in water and aerial leaves are well developed. •The spongy petiole is observed in Eicchornia which help in
buoyancy. •The leaves are dissected in Ceratophyllum.

15. Anatomical Adaptations:
Cuticle is absent.
Epidermis is single layered made
up of thin walled parenchyma cells.
So they can absorb water.
Cortex is well developed made up of parenchyma cells.
There are large air spaces surrounded by parenchyma cells called aerenchyma cells. They help in gaseous exchange and give buoyancy to plants.

16. Anatomical Adaptations:
Mechanical tissues are absent
to avoid rigidness of stem
Vascular tissues are poorly
developed. Xylem consists of only
tracheids.
In Nympheaea, special type of
star shaped lignified cells are present
which give mechanical support.
In submerged leaves stomata are totally absent so the exchange of gases is carried out by all the cells.
In floating leaves stomata are present on upper epidermis.

17. Physiological adaptations
These plants have low rate of absorption of minerals.
Transpiration is negligible.
Rate of photosynthesis is low.

18. THANK YOU