Trema (genus)

For other uses, see Trema (disambiguation).

Trema
File:Flowers & leaves I IMG 3453.jpg
Flowers & leaves of T. orientalis at Kolkata, West Bengal, India
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Rosids
Order:	Rosales
Family:	Cannabaceae
Genus:	Trema Lour.
Species
About 15 species; see text
Synonyms
Parasponia Miquel Sponia Planch

Trema is a genus of about 15 species of evergreen trees closely related to the hackberries (Celtis), occurring in subtropical and tropical regions of southern Asia, northern Australasia, Africa, South and Central America, and parts of North America. They are generally small trees, reaching 10–20 m (33–66 ft) tall.

Taxonomy

Previously included either in the elm family, Ulmaceae, or with Celtis in the Celtidaceae, genetic analysis has shown the Celtidaceae are best placed in the hemp family, Cannabaceae.

Description

The leaves are alternate, simple, 7–15 cm (2.8–5.9 in) long, ovate-acuminate to lanceolate with a long pointed tip, and evenly serrated margins. The fruit is a small drupe 3–5 mm (0.12–0.20 in) in diameter.

Species associations

Trema species are sometimes used as food plants by the larvae of hepialid moths of the genera Aenetus, including A. splendens, which burrow horizontally into the trunk then vertically down, and Endoclita, including E. malabaricus.

Uses

Trema orientalis is widely planted for land reclamation in southern Asia, valued for its tolerance of poor soils due to its ability to fix nitrogen. It is also an invasive species on some Pacific Ocean islands.

• Bark I IMG 3300.jpg

  Bark of T. orientalis at Kolkata, West Bengal, India

• Trema orientalis (Pigeon Wood) W IMG 2236.jpg

  Flowers of T. orientalis in Goa, India.

• Trema orientalis (Pigeon Wood) W2 IMG 2237.jpg

  Leaves of T. orientalis in Goa, India.

• Trema orientalis (Pigeon Wood) W2 IMG 2236.jpg

  Flowers of T. orientalis in Goa, India.

• Branches I IMG 3304.jpg

  Branches of T. orientalis at Kolkata, West Bengal, India

Selected species

• Trema cannabina Lour. – Lesser trema
• Trema cubense Urb.
• Trema discolor (Brongniart) Blume
• Trema domingensis Urb.
• Trema integerrima (Beurl.) Standl.
• Trema lamarckiana (Roem. & Schult.) Blume – West Indian trema, Lamarck's trema
• Trema micrantha (L.) Blume – Jamaican nettle tree
• Trema orientalis (L.) Blume – Pigeon wood
• Trema philippinensis Elmer
• Trema strigilosa Lundell
• Trema tomentosa (Roxb.) H.Hara – Poison peach
  • Trema tomentosa var. viridis (Planch.) Hewson

T. tomentosa var. viridis is a common shrub or small tree throughout eastern Australia.

External links

• Pacific Island Ecosystems at Risk (PIER) page on Trema orientalis (with photos)