Trema
Flowers & leaves of Trema orientale at Kolkata, West Bengal, India
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Rosales
Family: Cannabaceae
Genus: Trema
Lour. 1790
Species

About 15 species; see text

Synonyms
  • Parasponia Miq. 1851
  • Sponia Comm. ex Decne. 1834

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.[1] 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.[2]

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.

Some Trema species unusually able to live in symbiosis with rhizobia for nitrogen fixation as a non-legume. In this case it is customary to mention these species as a separate genus Parasponia.[3]

Uses

Trema orientale 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.[4]

Species

Trema comprises the following species:[5]

  1. Trema andersonii (Planch.) Byng & Christenh.
  2. Trema angustifolium (Planch.) Blume
  3. Trema cannabina Lour. – type species - Lesser trema (many synonyms including T. vieillardii (Planch.) Schltr.)
  4. Trema cubense Urb.
  5. Trema discolor (Brongniart) Blume
  6. Trema domingense Urb.
  7. Trema eurhynchum (Miq.) Byng & Christenh.
  8. Trema humbertii J.-F.Leroy
  9. Trema lamarckianum (Roem. & Schult.) Blume – West Indian trema, Lamarck's trema
  10. Trema levigatum Hand.-Mazz.
  11. Trema melastomatifolium (J.J.Sm.) Byng & Christenh.
  12. Trema micranthum (L.) Blume – Jamaican nettle tree
  13. Trema nitidum C.J. Chen
  14. Trema orientale (L.) Blume – Pigeon wood (synonym T. affinis (Planch.) Blume, T. orientalis)
  15. Trema parviflorum (Miq.) Byng & Christenh.
  16. Trema politoria (Planch.) Blume
  17. Trema simulans (Merr. & L.M.Perry) Byng & Christenh.
  18. Trema tomentosum (Roxb.) H.Hara – Poison peach
    1. var. tomentosum (Roxb.) H.Hara
    2. var. viride (Planch.) Hewson – eastern Australia (synonym T. asperum (Brongn.) Blume)

Species names with uncertain taxonomic status

The status of the following species is unresolved:[6]

References

  1. ^ "Trema micrantha (L.) Blume Jamaican nettletree". The PLANTS Database. United States Department of Agriculture. Retrieved 2009-10-06.
  2. ^ Sytsma, Kenneth J.; Morawetz, Jeffery; Pires, J. Chris; Nepokroeff, Molly; Conti, Elena; Zjhra, Michelle; Hall, Jocelyn C. & Chase, Mark W. (2002), "Urticalean rosids: Circumscription, rosid ancestry, and phylogenetics based on rbcL, trnL-F, and ndhF sequences", American Journal of Botany, 89 (9): 1531–1546, doi:10.3732/ajb.89.9.1531, PMID 21665755, S2CID 207690258
  3. ^ Op den Camp, R; Streng, A; De Mita, S; Cao, Q; Polone, E; Liu, W; Ammiraju, JS; Kudrna, D; Wing, R; Untergasser, A; Bisseling, T; Geurts, R (18 February 2011). "LysM-type mycorrhizal receptor recruited for rhizobium symbiosis in nonlegume Parasponia". Science. 331 (6019): 909–12. doi:10.1126/science.1198181. PMID 21205637.
  4. ^ Hanum, Faridah; van der Maeson, L.J.G (1997). "Plant Resources of South East Asia" (PDF). Core. p. 25. Retrieved 2022-11-14.
  5. ^ Govaerts R. "Trema Lour". Plants of the World Online. Board of Trustees of the Royal Botanic Gardens, Kew. Retrieved 22 March 2023.
  6. ^ "The Plant List entry for Trema". The Plant List, v.1.1. Royal Botanic Gardens, Kew and the Missouri Botanical Garden. September 2013. Retrieved 14 December 2020.

External links

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