
An epiphyte is a
plant
Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with c ...
or
plant-like organism that grows on the surface of another plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphytes grow are called
phorophytes. Epiphytes take part in
nutrient cycles and add to both the diversity and biomass of the ecosystem in which they occur, like any other organism. In some cases, a rainforest tree's epiphytes may total "several tonnes" (several long tons). They are an important source of food for many species. Typically, the older parts of a plant will have more epiphytes growing on them. Epiphytes differ from
parasites in that they grow on other plants for physical support and do not necessarily affect the host negatively. An organism that grows on another organism that is not a plant may be called an
epibiont. Epiphytes are usually found in the
temperate zone
In geography, the temperate climates of Earth occur in the middle latitudes (approximately 23.5° to 66.5° N/S of the Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ra ...
(e.g., many
moss
Mosses are small, non-vascular plant, non-vascular flowerless plants in the taxonomic phylum, division Bryophyta (, ) ''sensu stricto''. Bryophyta (''sensu lato'', Wilhelm Philippe Schimper, Schimp. 1879) may also refer to the parent group bryo ...
es,
liverworts
Liverworts are a group of non-vascular plant, non-vascular embryophyte, land plants forming the division Marchantiophyta (). They may also be referred to as hepatics. Like mosses and hornworts, they have a gametophyte-dominant life cycle, in wh ...
,
lichen
A lichen ( , ) is a hybrid colony (biology), colony of algae or cyanobacteria living symbiotically among hypha, filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualism (biology), m ...
s, and
algae) or in the tropics (e.g., many
ferns,
cacti,
orchid
Orchids are plants that belong to the family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant. Orchids are cosmopolitan plants that are found in almost every habitat on Eart ...
s, and
bromeliads). Epiphyte species make good
houseplants due to their minimal water and soil requirements. Epiphytes provide a rich and diverse habitat for other organisms including animals, fungi, bacteria, and
myxomycetes.
Epiphyte is one of the subdivisions of the
Raunkiær system.
The term ''epiphytic'' derives . Epiphytic plants are sometimes called "air plants" because they do not root in soil. However, that term is inaccurate, as there are many aquatic species of
algae
Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...
that are epiphytes on other aquatic plants (seaweeds or aquatic
angiosperms).
Terrestrial epiphytes
The best-known epiphytic plants include
moss
Mosses are small, non-vascular plant, non-vascular flowerless plants in the taxonomic phylum, division Bryophyta (, ) ''sensu stricto''. Bryophyta (''sensu lato'', Wilhelm Philippe Schimper, Schimp. 1879) may also refer to the parent group bryo ...
es,
orchid
Orchids are plants that belong to the family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant. Orchids are cosmopolitan plants that are found in almost every habitat on Eart ...
s, and
bromeliads such as
Spanish moss (of the genus ''
Tillandsia''), but epiphytes may be found in every major group of the plant kingdom. Eighty-nine percent of (or about 24,000) terrestrial epiphyte species are
flowering plant
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...
s. The second largest group are the
leptosporangiate ferns, with about 2,800 species (10% of epiphytes). About one-third of all fern species are epiphytes. The third largest group is
clubmosses, with 190 species, followed by a handful of species in each of the
spikemosses, other ferns,
Gnetales, and
cycads.
The first important monograph on epiphytic
plant ecology was written by
A. F. W. Schimper (, 1888). Assemblages of large epiphytes occur most abundantly in moist
tropical forests, but mosses and lichens occur as epiphytes in almost all biomes. In Europe there are no dedicated epiphytic plants using roots, but rich assemblages of mosses and lichens grow on trees in damp areas (mainly the western coastal fringe), and the common
polypody fern grows epiphytically along branches. Rarely, grass, small bushes or small trees may grow in
suspended soils up trees (typically in a rot-hole).
Holo-epiphyte or hemi-epiphyte
Epiphytes however, can generally be categorized into holo-epiphytes or hemi-epiphytes. A holo-epiphyte is a plant that spends its whole life cycle without contact with the ground and a hemi-epiphyte is a plant that spends only half of its life without the ground before the roots can reach or make contact with the ground.
Orchids are a common example of holo-epiphytes and
Strangler Figs are an example of hemi-epiphytes.
Plant nutrient relations
Epiphytes are not connected to the soil, and consequently must get nutrients from other sources, such as fog, dew, rain and mist,
or from nutrients being released from the ground rooted plants by decomposition or leaching, and dinitrogen fixation.
Epiphytic plants attached to their hosts high in the
canopy have an advantage over herbs restricted to the ground where there is less light and herbivores may be more active. Epiphytic plants are also important to certain animals that may live in their water reservoirs, such as some types of
frog
A frog is any member of a diverse and largely semiaquatic group of short-bodied, tailless amphibian vertebrates composing the order (biology), order Anura (coming from the Ancient Greek , literally 'without tail'). Frog species with rough ski ...
s and
arthropod
Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metam ...
s.
Epiphytes can have a significant effect on the microenvironment of their host, and of ecosystems where they are abundant, as they hold water in the canopy and decrease water input to the soil. Some non-vascular epiphytes such as lichens and mosses are well known for their ability to take up water rapidly. Epiphytes create a significantly cooler and more moist environment in the host plant canopy, potentially greatly reducing water loss by the host through transpiration.
Plant metabolism
CAM metabolism, a water-preserving metabolism present among various
plant taxa, is particularly relevant to epiphytic communities. For example, it is estimated that among epiphytic orchids, as many as 50% are likely to use it. Other relevant epiphytic families which display such metabolism are
Bromeliacee (e.g. in genera ''
Aechmea'' and ''Tillandsia''),
Cactaceae (e.g. in ''
Rhipsalis'' and ''
Epiphyllum'') and
Apocynaceae
Apocynaceae (, from '' Apocynum'', Greek for "dog-away") is a family of flowering plants that includes trees, shrubs, herbs, stem succulents, and vines, commonly known as the dogbane family, because some taxa were used as dog poison. Notable mem ...
(e.g. in ''
Hoya'' and ''
Dischidia'').
Marine epiphytes
The ecology of epiphytes in marine environments differs from those in terrestrial ecosystems. Epiphytes in marine systems are species of algae, bacteria, fungi, sponges, bryozoans, ascidians, protozoa, crustaceans, molluscs and any other sessile organism that grows on the surface of a plant, typically
seagrasses or algae.
Settlement of epiphytic species is influenced by a number of factors including light, temperature, currents, nutrients, and trophic interactions. Algae are the most common group of epiphytes in marine systems.
Photosynthetic epiphytes account for a large amount of the photosynthesis in systems in which they occur.
This is typically between 20 and 60% of the total primary production of the ecosystem.
They are a general group of organisms and are highly diverse, providing food for a great number of fauna.
Snail and nudibranch species are two common grazers of epiphytes.
Epiphyte
species composition and the amount of epiphytes can be indicative of changes in the environment. Recent increases in epiphyte abundance have been linked to excessive nitrogen put into the environment from farm runoff and storm water. High abundance of epiphytes are considered detrimental to the plants that they grow on often causing damage or death, particularly in seagrasses.
This is because too many epiphytes can block access to sunlight or nutrients. Epiphytes in marine systems are known to grow quickly with very fast generation times.
See also
*
Lithophyte – a plant that grows on rocks
* ''
Tillandsia'' – a genus of the
Bromeliaceae
* ''
Epiphyllum'' – a genus of epiphytic
cacti
*
Parasitic plant
A parasitic plant is a plant that derives some or all of its nutritional requirements from another living plant. They make up about 1% of angiosperms and are found in almost every biome. All Parasite, parasitic plants develop a specialized organ ...
*
Epilith, an organism that grows in a rock
*
Foliicolous, lichens or bryophytes that grow on leaves of vascular plants
*
Epiphytic bacteria
*
Epiphytic fungus
*
Canopy soils
References
External links
Epiphytes on a Scot's Pine in Gorbie Glen, Scotland
{{Authority control
Ecology terminology
Plant morphology
Plant life-forms
Plants by habit