''Trema'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

evergreen In botany, an evergreen is a plant which has Leaf, foliage that remains green and functional throughout the year. This contrasts with deciduous plants, which lose their foliage completely during the winter or dry season. Consisting of many diffe ...

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, e.g., including only woody plants with secondary growth, only ...

s closely related to the hackberries (''

Celtis ''Celtis'' is a genus of about 60–70 species of deciduous trees, commonly known as hackberries or nettle trees, in the hemp family Cannabaceae. It has a cosmopolitan distribution. Description ''Celtis'' species are generally medium-sized tree ...

''), occurring in subtropical and tropical regions of southern Asia, northern

Australasia Australasia is a subregion of Oceania, comprising Australia, New Zealand (overlapping with Polynesia), and sometimes including New Guinea and surrounding islands (overlapping with Melanesia). The term is used in a number of different context ...

, Africa, South and

Central America Central America is a subregion of North America. Its political boundaries are defined as bordering Mexico to the north, Colombia to the southeast, the Caribbean to the east, and the Pacific Ocean to the southwest. Central America is usually ...

, and parts of North America. They are generally small trees, reaching tall.

Taxonomy

Previously included either in the

elm Elms are deciduous and semi-deciduous trees comprising the genus ''Ulmus'' in the family Ulmaceae. They are distributed over most of the Northern Hemisphere, inhabiting the temperate and tropical- montane regions of North America and Eurasia, ...

family,

Ulmaceae The Ulmaceae () are a family (biology), family of flowering plants that includes the elms (genus ''Ulmus''), and the zelkovas (genus ''Zelkova''). Members of the family are widely distributed throughout the Temperate, north temperate zone, and ha ...

, or with ''Celtis'' in the Celtidaceae, genetic analysis has shown the Celtidaceae are best placed in the

hemp Hemp, or industrial hemp, is a plant in the botanical class of ''Cannabis sativa'' cultivars grown specifically for industrial and consumable use. It can be used to make a wide range of products. Along with bamboo, hemp is among the fastest ...

family,

Cannabaceae Cannabaceae is a small family of flowering plants, known as the hemp family. As now circumscribed, the family includes about 170 species grouped in about 11 genera, including '' Cannabis'' (hemp), '' Humulus'' (hops) and '' Celtis'' (hackberri ...

Description

The

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

are alternate, simple, long, ovate-acuminate to lanceolate with a long pointed tip, and evenly serrated margins. The

fruit In botany, a fruit is the seed-bearing structure in flowering plants (angiosperms) that is formed from the ovary after flowering. Fruits are the means by which angiosperms disseminate their seeds. Edible fruits in particular have long propaga ...

is a small

drupe In botany, a drupe (or stone fruit) is a type of fruit in which an outer fleshy part (exocarp, or skin, and mesocarp, or flesh) surrounds a single shell (the ''pip'' (UK), ''pit'' (US), ''stone'', or ''pyrena'') of hardened endocarp with a seed ...

in diameter.

Species associations

''Trema'' species are sometimes used as food plants by the

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

e of hepialid

moth Moths are a group of insects that includes all members of the order Lepidoptera that are not Butterfly, butterflies. They were previously classified as suborder Heterocera, but the group is Paraphyly, paraphyletic with respect to butterflies (s ...

s of the genera ''

Aenetus ''Aenetus'' is a genus of moths of the family Hepialidae. There are 24 described species found in Indonesia, New Guinea, New Caledonia, Australia and New Zealand. Most species have green or blue forewings and reddish hindwings, but some are predomi ...

'', including ''A. splendens'', which burrow horizontally into the trunk then vertically down, and ''

Endoclita ''Endoclita'' is a genus of moths of the family Hepialidae. There are 60 described species found in eastern and southeast Asia and the Indian subcontinent. Species *'' Endoclita aboe'' – India *'' Endoclita absurdus'' – China *'' Endoclita ...

'', including ''E. malabaricus''. Some ''Trema'' species unusually able to live in symbiosis with

rhizobia Rhizobia are diazotrophic bacteria that fix nitrogen after becoming established inside the root nodules of legumes (Fabaceae). To express genes for nitrogen fixation, rhizobia require a plant host; they cannot independently fix nitrogen. I ...

for nitrogen fixation as a non-legume. In this case it is customary to mention these species as a separate genus ''Parasponia''.

Uses

Trema orientale ''Trema orientale'' (sometimes ''Trema orientalis'') is a species of flowering plant, flowering tree in the Cannabis, hemp family, Cannabaceae. The basionym of ''T. orientalis'', ''Celtis orientalis'' was originally described and publis ...

'' is widely planted for land reclamation in southern Asia, valued for its tolerance of poor soils due to its ability to fix

nitrogen Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...

. It is also an

invasive species An invasive species is an introduced species that harms its new environment. Invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. The term can also be used for native spec ...

on some Pacific Ocean islands. Image:Bark I IMG 3300.jpg, Bark of '' T. orientalis'' at Kolkata, West Bengal, India File:Trema orientalis (Pigeon Wood) W IMG 2236.jpg, Flowers of ''T. orientale'' in

Goa Goa (; ; ) is a state on the southwestern coast of India within the Konkan region, geographically separated from the Deccan highlands by the Western Ghats. It is bound by the Indian states of Maharashtra to the north, and Karnataka to the ...

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

. File:Trema orientalis (Pigeon Wood) W2 IMG 2237.jpg, Leaves of ''T. orientale'' in

. File:Trema orientalis (Pigeon Wood) W2 IMG 2236.jpg, Flowers of ''T. orientale'' in

. Image:Branches I IMG 3304.jpg, Branches of ''T. orientale'' at Kolkata, West Bengal, India

Species

''Trema'' comprises the following species: # ''

Trema andersonii Trema may refer to: * a Greek and Latin root meaning ''hole'' * Trema, a term for the two dots (diacritic) ** Tréma, (French), a diaeresis * ''Trema'' (plant), a genus of about 15 species of small evergreen trees * Tréma (record label), a Fre ...

'' (Planch.) Byng & Christenh. # ''

Trema angustifolium Trema may refer to: * a Greek and Latin root meaning ''hole'' * Trema, a term for the two dots (diacritic) ** Tréma, (French), a diaeresis * ''Trema'' (plant), a genus of about 15 species of small evergreen trees * Tréma (record label), a Fre ...

'' (Planch.) Blume # ''

Trema cannabina ''Trema cannabina'' is a species of flowering plant in the family ''Cannabaceae''. This tree is found in Southeast Asia and Oceania. They are perennial. It is found in sandy, well drained soil. It also goes by the names of lesser ''Trema'' and p ...

'' Lour. – type species - Lesser trema (many synonyms including ''T. vieillardii'' (Planch.) Schltr.) # ''

Trema cubense Trema may refer to: * a Greek and Latin root meaning ''hole'' * Trema, a term for the two dots (diacritic) ** Tréma, (French), a diaeresis * ''Trema'' (plant), a genus of about 15 species of small evergreen trees * Tréma (record label), a Fre ...

Urb. Ignatz Urban (7 January 1848 – 7 January 1931) was a German botany, botanist. He is known for his contributions to the flora of the Caribbean and Brazil, and for his work as curator of the Botanical Garden in Berlin, Berlin Botanical Garden. B ...

# ''

Trema discolor ''Trema discolor'' is a species of plant in the family Cannabaceae. It is endemic to French Polynesia. It is native to the Society Islands and to Raivavae in the Tubuai Islands. Status It is listed as least concern A least-concern species ...

'' (Brongniart) Blume # ''

Trema domingense Trema may refer to: * a Greek and Latin root meaning ''hole'' * Trema, a term for the two dots (diacritic) ** Tréma, (French), a diaeresis * ''Trema'' (plant), a genus of about 15 species of small evergreen trees * Tréma (record label), a Fre ...

'' Urb. # '' Trema eurhynchum'' (Miq.) Byng & Christenh. # '' Trema humbertii'' J.-F.Leroy # ''

Trema lamarckianum ''Trema lamarckianum'', Lamarck's trema, West Indian nettle tree, or pain-in-the-back is a plant species in the genus ''Trema'' of the family Cannabaceae. It is a small evergreen shrub that is native of Florida and the West Indies. It has several ...

'' (Roem. & Schult.) Blume – West Indian trema, Lamarck's trema # '' Trema levigatum'' Hand.-Mazz. # '' Trema melastomatifolium'' (J.J.Sm.) Byng & Christenh. # '' Trema micranthum'' (L.) Blume – Jamaican nettle tree # '' Trema nitidum'' C.J. Chen # ''

'' (L.) Blume – Pigeon wood (synonym ''T. affinis'' (Planch.) Blume, ''T. orientalis'') # '' Trema parviflorum'' (Miq.) Byng & Christenh. # ''

Trema politoria Trema may refer to: * a List of Greek and Latin roots in English/P–Z#T, Greek and Latin root meaning ''hole'' * Trema, a term for the two dots (diacritic) ** Tréma, (French), a diaeresis (diacritic), diaeresis * Trema (plant), ''Trema'' (plant) ...

'' (Planch.) Blume # '' Trema simulans'' (Merr. & L.M.Perry) Byng & Christenh. # '' Trema tomentosum'' (Roxb.) H.Hara – Poison peach ## var. ''tomentosum'' (Roxb.) H.Hara ## var. ''viride'' (Planch.) Hewson – eastern

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

(synonym ''T. asperum'' (Brongn.) Blume)

Species names with uncertain taxonomic status

The status of the following species is unresolved: * ''Trema acuminatissima'' Boerl. * ''Trema argentea'' Blume * ''Trema blancoi'' Blume * ''Trema bracteolata'' Blume * ''Trema burmanni'' Blume * ''Trema carinata'' Blume * ''Trema crassifolia'' Liebm. * ''Trema glabrescens'' Blume * ''Trema glomerata'' Blume * ''Trema griffithii'' Blume * ''Trema guinensis'' Priemer * ''Trema imbricata'' Blume * ''Trema lancifolia'' Ridl. * ''Trema malaccensis'' Gand. * ''Trema morifolia'' Blume * ''Trema pallida'' Blume * ''Trema philippinensis'' Elmer * ''Trema pubigera'' Blume * ''Trema rigida'' Blume * ''Trema rugosa'' Blume * ''Trema scaberrima'' Blume * ''Trema sieberi'' Blume * ''Trema strigilosa'' Lundell * ''Trema strigosa'' Blume * ''Trema viridis'' Blume * ''Trema vulcanica'' Merr.

References

External links

* *
Pacific Island Ecosystems at Risk (PIER) page on ''Trema orientalis'' (with photos)
{{Taxonbar, from=Q945999 Rosales genera