Xerophyte

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Xerophyte

A xerophyte or xerophytic organism (xero meaning dry, phyte meaning plant) is a plant

Plant

Plants are Life organisms belonging to the Kingdom Plantae. They include familiar organisms such as trees, herbs, bushes, grasses, vines, ferns, mosses, and green algae....
which is able to survive in an environment with little available water or moisture, usually in environments where potential evapotranspiration

Evapotranspiration

Evapotranspiration is a term used to describe the sum of evaporation and plant transpiration from the earth's land surface to atmosphere. Evaporation accounts for the movement of water to the air from sources such as the soil, canopy interception, and waterbody....
exceeds precipitation for all or part of the growing season. Plants like the cactus

Cactus

A cactus is any member of the spine plant family Cactaceae, native to the Americas. They are often used as ornamental plants, but some are also Crop plants....
and other succulents are typically found in deserts where low rainfall amounts are the norm, but xerophytes such as the bromeliads can also be found in moist habitats such as tropical forests, exploiting niches where water supplies are limited or too intermittent for mesophytic

Mesophyte

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Encyclopedia

A xerophyte or xerophytic organism (xero meaning dry, phyte meaning plant) is a plant

Plant

Evapotranspiration

Cactus

Mesophyte

Mesophytes are terrestrial plants which are adapted to neither a particularly dry nor particularly wet environment. An example of a mesophytic habitat would be a rural temperate meadow, which might contain Solidago, Trifolium, Leucanthemum vulgare, and Rosa multiflora....
plants. Plants that live under arctic conditions may also have a need for xerophytic adaptations, as water is unavailable for uptake when the ground is frozen. Their leaves are covered with silvery hairs (creates wind break & light reflective surface).

Adaptations of xerophytes include reduced permeability of the epidermal

Epidermis (botany)

The epidermis is a single-layered group of cells that covers plants leaf, flowers, roots and Plant stem. It forms a boundary between the plant and the external world....
layer, stomata and cuticle

Plant cuticle

Plant cuticles are a protective waxy covering produced only by the Epidermis of leaf, young shoots and all other aerial plant organs without periderm....
to maintain optimal amounts of water in the tissues by reducing transpiration, adaptations of the root system to acquire water from deep underground sources or directly from humid atmospheres (as in epiphytic orchids), and succulence

Succulent plant

Succulent plants, also known as succulents or fat plants, are water-retaining plants adapted to arid climate or soil conditions. Succulent plants store water in their leaf, Plant stem and/or roots....
, or storage of water in swollen stems, leaves or root tissues. The typical morphological

Morphology (biology)

The term morphology in biology refers to form, structure and configuration of an organism. This includes aspects of the outward appearance as well as the form and structure of the internal parts like bones and organs....
consequences of these adaptations are collectively called xeromorphisms.

Mechanism table

Mechanism	Adaptation	Example
Limit water loss	waxy stomata	prickly pear
	few stomata
	sunken stomata	pine Pine Pines are Pinophyta trees in the genus *Pinus, in the family Pinaceae. They make up the monotypic subfamily Pinoideae*. There are about 115 species of pine, although different authorities accept between 105 and 125 species....
	stomata open at night	tea plant
	CAM Crassulacean acid metabolism Crassulacean acid metabolism, also known as CAM photosynthesis, is an elaborate carbon fixation pathway in some plants. These plants fix carbon dioxide during the night, storing it as the four carbon acid malate.... photosynthesis	cactus Cactus A cactus is any member of the spine plant family Cactaceae, native to the Americas. They are often used as ornamental plants, but some are also Crop plants....
	large hairs on surface	Bromeliads
	curled leaves Leaves Leaves are an Iceland five-piece alternative rock band who formed in 2001. They came to prominence in 2002 with their debut album, Breathe, drawing comparisons to groups such as Coldplay and Doves....	esparto grass
Storage of water	succulent leaves	Bryophyllum Bryophyllum The Bryophyllums are a section in the plant genus Kalanchoe of the Crassulaceae family . There are about twenty to thirty species in the group, native originally of South Africa, Madagascar, and Asia....
	succulent stems Plant stem A stem is one of two main structural axes of a vascular plant. The stem is normally divided into nodes and internodes, the nodes hold buds which grow into one or more leaf, inflorescence , conifer cones or other stems etc....	Euphorbia
	fleshy tuber Tuber Tubers are various types of modified plant structures that are enlarged to store nutrients. They are used by plants to overwinter and regrow the next year and as a means of asexual reproduction....	Raphionacme
Water uptake	deep root system Root In vascular plants, the root is the organ of a plant body that typically lies below the surface of the soil. This is not always the case, however, since a root can also be aerial root or aerating ....	Acacia Acacia *Acacia* is a genus of shrubs and trees belonging to the subfamily Mimosoideae of the family Fabaceae, first described in Africa by the Sweden botanist Carolus Linnaeus in 1773.... ,\|"prosopis Prosopis *Prosopis* is a genus of about 45 species of legume Spine trees and shrubs found in subtropical and tropical regions of the Americas, Africa and southwest Asia.... "\|
	below water table Water table The water table is the level at which the ground water pressure is equal to atmospheric pressure. It may be conveniently visualized as the 'surface' of the Groundwater in a given vicinity....	Nerium oleander
	absorbing surface moisture from leaf hairs or trichomes	Tillandsia Tillandsia The plant genus *Tillandsia*, a member of the Bromeliad family , is found in the deserts, forests and mountains of Central America and South America, and Mexico and the southern United States in North America....

Importance of water conservation

If the water potential

Water potential

Water potential is the potential energy of water relative to pure free water in reference conditions. It quantifies the tendency of water to move from one area to another due to osmosis, gravity, mechanical pressure, or matrix effects including surface tension....
inside the leaf is higher than outside the leaf, the water vapour will diffuse

Diffusion

Molecular diffusion, often called simply diffusion, is a net transport of molecules from a region of higher concentration to one of lower concentration by random molecular motion....
out of the leaf down this gradient. This loss of water vapour from the leaves is called transpiration

Transpiration

Transpiration is the evaporation of water from the aerial parts of plants, especially leaf but also Plant stems, flowers and roots. Leaf surfaces are dotted with openings called stoma that are bordered by guard cells....
, and the water vapour diffuses through open stomata in the leaf. Although this is a normal and important process in all plants, it is vital that plants living in dry conditions have adaptations that decrease this water potential gradient, and decrease the size of open stomata, in order to reduce water loss from the plant. It is important for a plant living in these conditions to conserve water because without enough water, plant cells lose turgor and the plant tissue wilts. If the plant loses too much water, it will pass its permanent wilting point

Permanent wilting point

Permanent wilting point or wilting point is defined as the minimal point of soil moisture the plant requires not to wilt. If moisture decreases to this or any lower point a plant wilts and can no longer recover its turgidity when placed in a saturated atmosphere for 12 hours....
, where the plant will die.

Types of xerophytic plants are:

Succulent plant
Succulent plant

Succulent plants, also known as succulents or fat plants, are water-retaining plants adapted to arid climate or soil conditions. Succulent plants store water in their leaf, Plant stem and/or roots....
s - typically store water in stems or leaves. They include the Cactaceae family which typically have stems that are round and store a lot of water. Often, as in cacti where the leaves are reduced to spines, their leaves are vestigial, or they do not have leaves.
Bulb
Bulb

A bulb is an underground vertical shoot that has modified leaf that are used as food storage organs by a dormancy plant.A bulb's leaf bases generally do not support leaves, but contain food reserves to enable the plant to survive adverse conditions....
s - water is stored in their bulbs, at or below ground level. They may spend a period of dormancy during drought conditions underground, and are therefore known as drought evaders.
Short-lived annuals can often germinate following rainfall. An example of this is the California poppy
California poppy

The California poppy is native to grassy and open areas from sea level to 2,000m altitude in the western United States throughout California, extending to Oregon, southern Washington, Nevada, Arizona, New Mexico, and in Mexico in Sonora and northwest Baja California....
whose seeds lie dormant during drought and then, flower
Flower

A flower, sometimes known as a bloom or blossom, is the reproduction structure found in flowering plants . The biological function of a flower is to mediate the union of male sperm with female ovum in order to produce seeds....
and form seeds within four weeks of rainfall.

Xerophyte

Mechanism table

Importance of water conservation

See also