Elaeagnaceae
Encyclopedia
Elaeagnaceae, the oleaster family, is a plant
family
of the order
Rosales
comprising small tree
s and shrub
s, native to temperate regions of the Northern Hemisphere
, south into tropical Asia
and Australia
. The family has 45-50 species
in three genera
.
They are commonly thorny
, with simple leaves
often coated with tiny scales or hairs. Most of the species are xerophyte
s (found in dry habitat
s); several are also halophyte
s, tolerating high levels of soil salinity
.
The Elaeagnaceae often harbor nitrogen-fixing actinomycetes of the genus Frankia
in their roots, making them useful for soil reclamation. This characteristic, together with their production of plentiful seeds, often results in Eleagnaceae being viewed as weeds.
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
of the order
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
Rosales
Rosales
Rosales is an order of flowering plants. It is one of the four orders in the nitrogen fixing clade of the fabids and is sister to a clade consisting of Fagales and Cucurbitales. It contains about 7700 species, distributed into about 260 genera. Rosales comprises nine families, the type family...
comprising small tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
s and shrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
s, native to temperate regions of the Northern Hemisphere
Northern Hemisphere
The Northern Hemisphere is the half of a planet that is north of its equator—the word hemisphere literally means “half sphere”. It is also that half of the celestial sphere north of the celestial equator...
, south into tropical Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
and Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
. The family has 45-50 species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
in three genera
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
.
They are commonly thorny
Thorns, spines, and prickles
In botanical morphology, thorns, spines, and prickles are hard structures with sharp, or at least pointed, ends. In spite of this common feature, they differ in their growth and development on the plant; they are modified versions of different plant organs, stems, stipules, leaf veins, or hairs...
, with simple leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
often coated with tiny scales or hairs. Most of the species are xerophyte
Xerophyte
A xerophyte or xerophytic organism is a plant which has adapted to survive in an environment that lacks water, such as a desert. Xerophytic plants may have adapted shapes and forms or internal functions that reduce their water loss or store water during long periods of dryness...
s (found in dry habitat
Habitat (ecology)
A habitat is an ecological or environmental area that is inhabited by a particular species of animal, plant or other type of organism...
s); several are also halophyte
Halophyte
A halophyte is a plant that grows where it is affected by salinity in the root area or by salt spray, such as in saline semi-deserts, mangrove swamps, marshes and sloughs, and seashores. An example of a halophyte is the salt marsh grass Spartina alterniflora . Relatively few plant species are...
s, tolerating high levels of soil salinity
Salinity
Salinity is the saltiness or dissolved salt content of a body of water. It is a general term used to describe the levels of different salts such as sodium chloride, magnesium and calcium sulfates, and bicarbonates...
.
The Elaeagnaceae often harbor nitrogen-fixing actinomycetes of the genus Frankia
Frankia
Frankia is a genus of nitrogen fixing, filamentous bacteria that live in symbiosis with actinorhizal plants, similar to the Rhizobia bacteria that are found in the root nodules of legumes in the Fabaceae family. Bacteria of this genus also form root nodules.The genus Frankia was originally named by...
in their roots, making them useful for soil reclamation. This characteristic, together with their production of plentiful seeds, often results in Eleagnaceae being viewed as weeds.