The Urticaceae are a

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

, the nettle family, of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

s. The family name comes from the genus '' Urtica''. The Urticaceae include a number of well-known and useful plants, including nettles in the genus ''Urtica'',

ramie Ramie (pronounced: , ; from Malay ) is a flowering plant in the nettle family Urticaceae, native to eastern Asia. It is a herbaceous perennial growing to tall;

(''Boehmeria nivea''), māmaki (''

Pipturus albidus ''Pipturus albidus'', known as ''māmaki'' (sometimes ''waimea'', for its resemblance to olomea) in Hawaiian and known as Waimea pipturus in English, is a species of flowering plant in the nettle family, Urticaceae, that is endemic to Hawaii. ...

''), and ajlai (''

Debregeasia saeneb ''Debregieasia saenab'', also known as ajilai, is a shrub that can reach a height of 1.5-2.4m. It has dark reddish branchlets and dark green leaves at mature form; the upper side of leaves are green and lower side are white-grey colour. It is an ...

''). The family includes about 2,625 species, grouped into 53 genera according to the database of the

Royal Botanic Gardens, Kew Royal Botanic Gardens, Kew is a non-departmental public body in the United Kingdom sponsored by the Department for Environment, Food and Rural Affairs. An internationally important botanical research and education institution, it employs 1,10 ...

and Christenhusz and Byng (2016). The largest genera are ''

Pilea ''Pilea'', with 600–715 species, is the largest genus of flowering plants in the nettle family Urticaceae. It is distributed throughout the tropics, subtropics, and warm temperate regions (with the exception of Australia and New Zealand). Des ...

'' (500 to 715 species), ''

Elatostema ''Elatostema'' is a genus of flowering plants containing approximately 350 known species in the nettle family (biology), family Urticaceae, native plant, native to tropical forest clearings throughout Australasia, Asia and Africa. There may be as ...

'' (300 species), '' Urtica'' (80 species), and ''

Cecropia ''Cecropia'' is a Neotropical genus consisting of 61 recognized species with a highly distinctive lineage of dioecious trees. The genus consists of pioneer trees in the more or less humid parts of the Neotropics, with the majority of the speci ...

'' (75 species). ''

'' contains many myrmecophytes. Urticaceae species can be found worldwide, apart from the polar regions.

Description

Urticaceae species can be shrubs (e.g. ''

''), lianas, herbs (e.g. '' Urtica'', ''

Parietaria ''Parietaria'' is a genus of flowering plants in the family Urticaceae, native to temperate and tropical regions across the world.Flora Europaea''Parietaria''/ref>African Flowering Plants Database''Parietaria'' (enter genus name in search box)/ref ...

''), or, rarely, trees (''

Dendrocnide ''Dendrocnide'' is a genus of approximately 40 species of plants in the nettle family ''Urticaceae''. They have a wide distribution across North East India, Southeast Asia, Australia and the Pacific Islands. In Australia they are commonly known a ...

'', ''

''). Their leaves are usually entire and bear

stipule In botany, a stipule is an outgrowth typically borne on both sides (sometimes on just one side) of the base of a leafstalk (the petiole). Stipules are considered part of the anatomy of the leaf of a typical flowering plant, although in many speci ...

s. Urticating (stinging) hairs are often present. They have usually unisexual flowers and can be both monoecious or dioecious. They are wind-pollinated. Most disperse their pollen when the stamens are mature and their filaments straighten explosively, a peculiar and conspicuously specialised mechanism.

Taxonomy

The

APG II system The APG II system (Angiosperm Phylogeny Group II system) of plant classification is the second, now obsolete, version of a modern, mostly molecular-based, system of plant taxonomy that was published in April 2003 by the Angiosperm Phylogeny Gr ...

puts the Urticaceae in the order Rosales, while older systems consider them part of the

Urticales Urticales is an order of flowering plants. Before molecular phylogenetics became an important part of plant taxonomy, Urticales was recognized in many, perhaps even most, systems of plant classification, with some variations in circumscription. A ...

, along with

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

Moraceae The Moraceae — often called the mulberry family or fig family — are a family of flowering plants comprising about 38 genera and over 1100 species. Most are widespread in tropical and subtropical regions, less so in temperate climates; however ...

, and

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'' (hackberries ...

. APG still considers "old" Urticales a monophyletic group, but does not recognise it as an order on its own.

Fossil record

The

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

record of Urticaceae is scattered and mostly based on dispersed fruits. Twelve species based on fossil achenes are known from the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...

Central Europe Central Europe is an area of Europe between Western Europe and Eastern Europe, based on a common historical, social and cultural identity. The Thirty Years' War (1618–1648) between Catholicism and Protestantism significantly shaped the a ...

. Most were assigned to the extant genera ''

Boehmeria ''Boehmeria'' is a genus of 47 species of flowering plants in the nettle family Urticaceae. Of the species, 33 are indigenous to the Old World and 14 to the New World; no species is indigenous to both the Old and New Worlds. The species include ...

'' (three species), ''

Debregeasia ''Debregeasia'' is a genus of plants belonging to the family Urticaceae The Urticaceae are a family, the nettle family, of flowering plants. The family name comes from the genus ''Urtica''. The Urticaceae include a number of well-known and ...

'' (one species) and '' Pouzolzia'' (three species), while three species were assigned to the extinct genus ''Urticoidea''. A Colombian fossil flora of the

Maastrichtian The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interval ...

stage has yielded leaves that resemble leaves of the tribe Ceropieae. In the Cenozoic fossil leaves from the

Ypresian In the geologic timescale the Ypresian is the oldest age or lowest stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by the Eocene Lutetian Age. The Ypresian ...

Allenby Formation The Allenby formation is a sedimentary rock formation in British Columbia which was deposited during the Ypresian stage of the Early Eocene. It consists of conglomerates, sandstones with interbedded shales and coal. The shales contain an abunda ...

preserve distinct

trichome Trichomes (); ) are fine outgrowths or appendages on plants, algae, lichens, and certain protists. They are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae. A covering of any kind of hair on a p ...

s, and have been attributed to the Tribe Urticeae in the fossil record. The leaves had originally been identified as ''

Rubus ''Rubus'' is a large and diverse genus of flowering plants in the rose family, Rosaceae, subfamily Rosoideae, with over 1,350 species. Raspberries, blackberries, and dewberries are common, widely distributed members of the genus. Most of the ...

'' by earlier workers on the

Eocene Okanagan Highlands The Eocene Okanagan Highlands or Eocene Okanogan Highlands are a series of Early Eocene geological formations which span a transect of British Columbia, Canada, and Washington state, United States. Known for a highly diverse and detailed plant an ...

, but Devore ''et al'' (2020) interpreted the preserved hairs along the stem and major veins as stinging trichomes, rather than simple hairs or thorns.

Phylogeny

Modern

molecular phylogenetics Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

suggest the following relationships (see also ):

Tribes and genera

* Boehmerieae Gaudich. 1830 **'' Archiboehmeria'' C.J. Chen 1980 (1 sp.) **'' Astrothalamus'' C.B. Rob. 1911 (1 sp.) **''

'' Jacq. 1760 (80 spp.) **'' Chamabainia'' Wight 1853 (1–2 spp.) **'' Cypholophus'' Wedd. 1854 (15 spp.) **''

'' Gaudich. 1844 (4 spp.) **'' Gibbsia'' Rendle 1917 (2 spp.) **'' Gonostegia'' Turcz. 1846 (5 spp.) **'' Hemistylus'' Benth. 1843 (4 spp.) **'' Neodistemon'' Babu & A. N. Henry 1970 (1 sp.) **'' Neraudia'' Gaudich. 1830 (5 spp.) **'' Nothocnide'' Blume 1856 (4 spp.) **'' Oreocnide'' Miq. 1851 (15 spp.) **'' Phenax'' Wedd. 1854 (12 spp.) **'' Pipturus'' Wedd. 1854 (30 spp.) **'' Pouzolzia'' Gaudich. 1826 830/small> (70 spp.) **'' Rousselia'' Gaudich. 1826 830/small> (3 spp.) **'' Sarcochlamys'' Gaudich. 1844 (1 sp.) * Cecropieae Gaudich. 1830 **''

'' Loefl. 1758 (70–80 spp.) **''

Coussapoa ''Coussapoa'' is a genus of flowering plants belonging to the family Urticaceae. Its native range is Mexico, Central & Southern Tropical America. Species: *''Coussapoa angustifolia'' *''Coussapoa arachnoidea'' *''Coussapoa argentea'' *''Co ...

'' Aubl. 1775 (>50 spp.) **'' Leucosyke'' Zoll. & Moritzi 1845 (35 spp.) **'' Maoutia'' Wedd. 1854 (15 spp.) **'' Musanga'' R. Br. in Tuckey 1818 (2 spp.) **'' Myrianthus'' P. Beauv. 1804 805/small> (7 spp.) **'' Pourouma'' Aubl. 1775 (>50 spp.) * Elatostemateae Gaudich. 1830 **'' Aboriella'' Bennet (1 sp.) **'' Achudemia'' Blume 1856 **''

'' J.R. Forst. & G. Forst. 1775 (300 spp.) **'' Gyrotaenia'' Griseb. 1861 (4 spp.) **'' Lecanthus'' Wedd. 1854 (1 sp.) **'' Meniscogyne'' Gagnep. 1928 (2 spp.) **'' Myriocarpa'' Benth. 1844 846/small> (18 spp.) **'' Pellionia'' Gaudich. 1826 (60 spp.) **'' Petelotiella'' Gagnep. in Lecomte 1929 (1 spp.) **''

'' Lindl. 1821 (250 spp.) **'' Procris'' Comm. ex Juss. 1789 (20 spp.) **'' Sarcopilea'' Urb. 1912 (1 sp.) * Forsskaoleeae Gaudich. 1830 **'' Australina'' Gaudich. 1830 (2 spp.) **'' Didymodoxa'' E. Mey. ex Wedd. 1857 (2 spp.) **'' Droguetia'' Gaudich. 1830 (7 spp.) **'' Forsskaolea'' L. 1764 (6 spp.) * Parietarieae Gaudich. 1830 **''

Gesnouinia ''Gesnouinia'' is a small genus of flowering plants in the family Urticaceae (the nettle family). Two species are accepted by The Plant List :Search for "Gesnouinia", * ''Gesnouinia arborea'' (L.f.) Gaudich. * ''Gesnouinia filamentosa'' Wedd. ...

'' Gaudich. 1830 (2 spp.) **''

'' L. 1753 (20 spp.) **'' Soleirolia'' Gaudich. 1830 (1 sp.) * Urticeae Lamarck & DC. 1806 **''

'' Miq. 1851 (27 spp.) **'' Discocnide'' Chew 1965 (1 sp.) **'' Girardinia'' Gaudich. 1830 (2 spp.) **''

Hesperocnide ''Hesperocnide'' is a small genus of nettles containing two species. These are annual herbs covered in stinging hairs and toothed leaves. ''Hesperocnide sandwicensis'', the Hawaii nettle, is endemic to Hawaii. '' Hesperocnide tenella'', the wes ...

'' Torr. 1857 (2 spp.) **''

Laportea ''Laportea'' is a genus of plants in the family Urticaceae. They are herbaceous, either annual or perennial. Like many plants of the Urticaceae, they have stinging hairs. There are stinging and non-stinging hairs on the same plant. The genus was ...

'' Gaudich. 1826 830/small> (21 spp.) **'' Nanocnide'' Blume 1856 (2 spp.) **'' Obetia'' Gaudich. 1844 (7 spp.) **'' Poikilospermum'' Zipp. ex Miq. 1864 (20 spp.) **'' Touchardia'' Gaudich. 1847 (1–2 spp.) **'' Urera'' Gaudich. 1826 830/small> (35 spp.) **'' Urtica'' L. 1753—nettle (80 spp.) **'' Zhengyia'' T. Deng, D.G. Zhang & H. Sun 2013 (1 sp.) *''

Incertae sedis ' () or ''problematica'' is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertain ...

'' **'' Metatrophis'' F. Br. 1935 (1 sp.) **'' Parsana'' Parsa & Maleki 1952 (1 sp.)

Diseases

The Urticaceae are subject to many bacterial, viral, fungal, and nematode parasitic diseases. Among them are: * Bacterial leaf spot, caused by ''

Xanthomonas campestris ''Xanthomonas campestris'' is a bacterium that causes a variety of plant diseases, including "black rot" in cruciferous vegetables and bacterial wilt of turfgrass. It is also used in the commercial production of xanthan gum, a high-molecular-we ...

'' which affects '' Pellionia'', ''

'', and other genera * Anthracnose, a fungal disease caused by ''

Colletotrichum capsici ''Colletotrichum capsici'' is a species of fungus and plant pathogen which causes leaf blight on ''Chlorophytum borivilianum'', basil, chickpea and pepper as well as dieback in pigeonpea and anthracnose in poinsettia The poinsettia ( or ) ...

'' which affects ''Pilea'' * Myrothecium leaf spot, a fungal disease caused by ''

Myrothecium roridum ''Myrothecium roridum'' is a fungal plant pathogen. Myrotoxin B Myrotoxin B is a macrocyclic trichothecene first isolated in 1985. It was tested on Swiss mice and found to be very toxic, though not the most toxic of the three toxins that were t ...

'' which affects plants throughout the Urticaceae, as well as other angiosperms * Phytophthora blight, a water mold disease caused by '' Phytophthora nicotianae'' which affects ''Pilea'' * Southern blight, a fungal disease caused by '' Athelia rolfsii'' which affects both ''Pellionia'' and ''Pilea''

Image gallery

Image:PileaCadierei.jpg, ''Pilea cadierei'' Image:Pilea pumila2.JPG, ''Pilea pumila'' Image:Poisonivy1.jpg, ''Dendrocnide'' sp. Image:Elatostema umbellatum 2006.04.19 06.17.14-p4190208.jpg, ''Elatostema umbellatum'' Image:Brennnessel 1.JPG, ''Urtica dioica'' Image:Boehmeria nivea 1.jpg, ''Boehmeria nivea'' Image:Parietaria judaica 000.jpg, ''Parietaria judaica'' flowers Image:Nettle.jpg, ''Urtica dioica'' stinging hairs File:咬人狗 Dendrocnide meyeniana 20221020185903 03.jpg, Leaves of '' Dendrocnide meyeniana'' File:蕁麻(咬人貓) Urtica thunbergiana 20220406201651.jpg, The dotted bumps on the leaves of '' Urtica thunbergiana''

References

External links

* continuously updated. {{Taxonbar, from=Q156332 Rosid families