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i.) Xerophytes.
- Leaves are modified into thorns to reduce the surface area for transpiration.
- The plants may shed their leaves during dry season to reduce surface area dir transpiration.
- The plants have leaves with thick waxy cuticle to reduce the rate of transpiration.
- They have curled leaves hence exposing few stomata, thereby reducing transpiration.
- They have sunken stomata with moisture accumulation within the substomatal this causes less transpiration rate.
- Some have reversed stomatal rhythm to reduce transpiration rate.
- Some have succulent stems or leaves which store water.
ii.)Mesophytes.
- They have ability to loose excess water due to presence of stomata on both upper and lower side.
- They have shallow root system to absorb superficial water.
- They have waxy leaves which are glossy to reflect light.
- They have support devices to reach out for light.
- They exhibit fast growth rates in order to compete for light.
iii.) Halophytes.
- Presence of breathing roots known as pneumatophores which emerge above the water surface for gaseous exchange.
- Have root cells with ability to trap and concentrate salts so that the hypertonic level developed enables them to draw water by osmosis from their environment.
- They emerge above the water so as to carry out photosynthesis.
- Have prop roots for support.
- Have developed aerenchyma tissue for buoyancy.
iv.) Hydrophytes.
- Leaves emerge, float and have maximum number of stomata on the upper surface to provide a large surface area for gaseous exchange and transpiration.
- When submerged the plants have thinly divided structures which are threadlike to give a large surface area for maximum absorption of light.
- Have chloroplasts which are sensitive to low light intensity enabling them to synthesize food under low light intensity.
- The plants develop aerencyma tissue which reduce density for buoyancy and gaseous exchange.
- Leaves are covered by a waxy substance to reduce excessive water absorption.
- Floating species have long fibrous roots for absorption of mineral salts.
eddynightsy answered the question on April 30, 2018 at 09:55
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