Urticaceae

Nettle family
Urtica dioica (Stinging nettle)
Scientific classification
Kingdom:	Plantae
Division:	Magnoliophyta
Class:	Magnoliopsida
Order:	Rosales
Family:	Urticaceae Juss., 1789
Synonyms
Cecropiaceae C. C. Berg[1]

Urticaceae, or the nettle family, is a family of flowering plants. The family name comes from the genus Urtica (nettles). Urticaceae includes a number of well-known and useful plants, including the aforementioned nettles, Ramie (Boehmeria nivea), māmaki (Pipturus albidus), and ajlai (Debregeasia saeneb).

The family includes approximately 2600 species, grouped into 54 to 79 genera according to the database of the Royal Botanic Gardens, Kew. The largest genera are Pilea (500 to 715 species), Elatostema (300 species), Urtica (80 species), and Cecropia (75 species).

Urticaceae can be found worldwide, apart from the polar regions.

Taxonomy

Male and female flower of Urtica

APG II system puts Urticaceae in order Rosales, while older system consider it part of Urticales, along with Ulmaceae, Moraceae and Cannabaceae. APG still considers "old" Urticales a monophyletic group, but does not recognise it as an order on its own.

Description

Urticaceae can be shrubs (e.g. Pilea), lianas, herbs (e.g. Urtica. Parietaria), or, rarely, trees (e.g. Dendrocnide, Cecropia).

Leaves are usually entire and bear stipules. Urticating (stinging) hairs are often present.

Urticaceae have usually unisexual flowers and can be both monoecious or dioecious. They are pollinated by the wind. Most disperse their pollen when the stamens are mature and their filaments straighten explosively: a peculiar and conspicuously specialised mechanism.

Genera

Aboriella Achudemia Archiboehmeria Astrothalamus Australina Boehmeria Cecropia Chamabainia Coussapoa Cypholophus Debregeasia Dendrocnide Didymodoxa Discocnide Droguetia Elatostema

Forsskaolea Gesnouinia Gibbsia Girardinia Laportea Lecanthus Leucosyke Maoutia Meniscogyne Metatrophis[2] Myriocarpa Nanocnide Neodistemon Neraudia Nothocnide Obetia Oreocnide

Parietaria Pellionia Petelotiella Phenax Pilea Pipturus Pouzolzia Procris Rousselia Sarcochlamys Sarcopilea Soleirolia Touchardia Urera Urtica - nettle

Image gallery

• 

  Pilea cadierei

• 

  Pilea pumila

• 

  Dendrocnide sp.

• 

  Elatostema umbellatum

• 

  Urtica dioica

• 

  Boehmeria nivea

• 

  Parietaria judaica, flowers

• 

  Urtica dioica, stinging hairs

See also

• List of foliage plant diseases (Urticaceae)

References

1. ^ Germplasm Resources Information Network (GRIN) (2003-01-17). "Family: Urticaceae Juss., nom. cons.". Taxonomy for Plants. USDA, ARS, National Genetic Resources Program, National Germplasm Resources Laboratory, Beltsville, Maryland. http://www.ars-grin.gov/cgi-bin/npgs/html/family.pl?1165. Retrieved 2008-04-24. 
2. ^ "Metatrophis F. Br.". Germplasm Resources Information Network. United States Department of Agriculture. 2009-01-16. http://www.ars-grin.gov/cgi-bin/npgs/html/genusfamfind.pl?genus=Metatrophis*&ferns=ferns&gymno=gymno&angio=angio. Retrieved 2009-03-11. 

• Stevens, P. F. (2001 onwards). Angiosperm Phylogeny Website. Version 7, May 2006 [and more or less continuously updated since]. [1]
• (Italian) Sandro Pignatti, Flora d'Italia, Edagricole, Bologna 1982. ISBN 8850624492