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First teaching 2023

First exams 2025

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Xerophytic Plant Leaf Adaptations (CIE AS Biology)

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Cara Head

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Cara Head

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Xerophytic Plant Leaf Adaptations

  • Xerophytes (from the Greek xero for ‘dry’) are plants that are adapted to dry and arid conditions
  • Xerophytes have physiological and structural (xeromorphic) adaptations to maximise water conservation

Xeromorphic features table

Xerophytic Adaptations of Leaves Effect of Adaptation Example
Fleshy succulent leaves Store of water for times of low availability  Bryophyllum
"Hinge cells" shrink when flaccid Causes leaves to roll, exposing thick cuticle to the air and creating a humid space in the middle of the rolled leaf Marram Grass (Ammophila arenaria

Leaves reduced to scales, spines, needles.

Leaves curled, rolled or folded when flaccid

Reduced transpiration due to reduced surface area exposed

Cactus (Opuntia)

Marram Grass (Ammophila arenaria)

Stomata closed during light

Stomata open during night

Daytime water loss minimised

Carbon dioxide fixed at night

Pineapple, Yucca, American Aloe
Sunken stomata and leaf surface covered in fine hairs Water loss minimised as moist air is trapped and diffusion gradient reduced Pine, Nerium 
Reduced numbers of stomata Less water loss as fewer pores Nerium, Prickly pear
Thick waxy cuticles Water loss reduced via cuticle distance Pine, Prickly pear

Drawing Xerophytes Diagram

Xerophytic plant leaf adaptations, downloadable AS & A Level Biology revision notes

Photomicrograph and annotated drawing showing the xeromorphic features of a leaf of Ammophilia arenaria (Marram grass)

Examiner Tip

You will be expected to make annotated drawings of transverse sections of leaves from xerophytic plants to explain how they are adapted.

Remember not all leaves will have every feature listed above so if you are looking at an unfamiliar image consider whether the adaptations you can see will help reduce water being lost from the leaf.

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Cara Head

Author: Cara Head

Expertise: Biology

Cara graduated from the University of Exeter in 2005 with a degree in Biological Sciences. She has fifteen years of experience teaching the Sciences at KS3 to KS5, and Psychology at A-Level. Cara has taught in a range of secondary schools across the South West of England before joining the team at SME. Cara is passionate about Biology and creating resources that bring the subject alive and deepen students' understanding