Xerophyte

A xerophyte species Euphorbia virosa

Xerophytes are plants which are adapted to dry/desert areas. They are a type of succulent plant. To survive these harsh conditions they have special features. For example, a cactus has white hairs which help to prevent water loss. Another example is manzanita plants, which have a thick waxy coating and keep their leaves vertical to the sun.

Adaptions

Some Xerophytic plants sit out a drought. They can still extract water from soil. They may have very salty cell sap and therefore a very low water potential in the roots; they may have very extensive or deep roots or may pick up the slightest dew and survive on that.

Others have special features about their shape or structure (xeromorphs). Thick waxy cuticle (Aloe); hairy surfaces (Edelweiss); dense packing of leaves, reduced leaf size (species of cypress); reduced density of stomata (many cacti); pitted and grooved position of stomata (Ammophila) Water storage in stem and tubers, etc. (baobab). They may also protect this water store from animals by spines and chemicals.

Mechanism table

Mechanism	Adaptation	Example
Limit water loss	waxy stomata	prickly pear
	few stomata
	sunken stomata	pine
	stomata open at night	tea plant
	CAM photosynthesis provides CO2 during day when stomata are closed	cactus
	large hairs on surface	bromeliads
	curled leaves	esparto grass
Storage of water	succulent leaves	Kalanchoe
	succulent Plant stem	Euphorbia
	fleshy tuber	Raphionacme
Water uptake	deep root system	Acacia, Prosopis
	below water table	Nerium oleander
	absorbing surface moisture from leaf hairs or trichomes	Tillandsia

Xerophyte Media

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  Cistus albidus is a xerophyte which grows in European countries such as France, and Italy and North African countries like Morocco.

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  The succulent leaves of Dudleya brittonii are visibly coated with a 'powdery' white which is the epicuticular wax.

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  Dudleya pulverulenta is called 'chalk lettuce' for its obvious structures. This xerophyte has fleshy succulent leaves and is coated with chalky wax.

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  Line 1 represents typical mesophytic plants and line 2 represents xerophytes. The stomata of xerophytes are nocturnal and have inverted stomatal rhythm.

• A Rose of Jericho plant in dormancy re-flourishes when its roots are placed in a bowl of water.

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  A Geoffroea decorticans tree is both a winter and drought deciduous tree.

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  Agave americana is a versatile xerophyte. All parts of the plant can be used either for aesthetics, for consumption, or in traditional medicine.