Urticaceae Juss.
  • Gen. Pl. 400. 1789. (4 Aug 1789)
  • Nettle Family


Cite taxon page as 'WFO (2021): Urticaceae Juss. Published on the Internet;http://www.worldfloraonline.org/taxon/wfo-7000000631. Accessed on: 26 Sep 2021'

General Information

Herbs, subshrubs, or shrubs, rarely trees, very rarely climbing, stems often fibrous, sometimes succulent. sometimes armed with stinging hairs; epidermal cells of leaves, sometimes stems, perianths mostly with prominent cystoliths punctiform to linear; Leaves alternate or opposite, stipules present, rarely absent; leaf blade simple. Inflorescences cymose, paniculate, racemose, spicate, or cluster-capitate, usually formed from glomerules, sometimes crowded on common enlarged cuplike or discoid receptacle, rarely reduced into a single flower. Flowers unisexual (plants monoecious or dioecious), rarely bisexual in partial flowers; actinomorphic, very small, (1-)4- or 5-merous, rarely perianth absent in female flowers. Calyx absent. Perianth lobes imbricate or valvate. Male flowers: stamens as many as and opposite to perianth lobes, filaments inflexed in bud; anthers 2-locular, opening lengthwise, rudimentary ovary often present. Female flowers: perianth lobes free or connate, usually enlarged in fruit and persistent, occasionally absent; staminodes scarious, opposite to the perianth lobes, or absent. Ovary rudimentary in male flowers, sessile or shortly stipitate, free or adnate to the perianth; 1-locular, ovule solitary, erect from the base; style simple, or absent; stigma diverse, capitate, penicillate-capitate (brushlike), subulate, filiform, ligulate, or peltate. Fruit usually a dry achene, sometimes a fleshy drupe, often enclosed by the persistent perianth. Seed solitary, endosperm usually present; embryo straight; cotyledons ovate elliptical or orbicular.

  • Provided by: [E].Flora Of CHina @ efloras.org
    • Source: [
    • 5
    • 1
    • ]. 

    Herbs or small shrubs [lianas, trees], herbs annual or rhizomatous perennial, usually pubescent, sometimes with stinging hairs, deciduous. Leaves opposite or alternate and spirally arranged, simple; stipules present or absent; petioles present. Leaf blades paired, equal in size (except in Pilea , which may have unequally paired leaves), dotted with linear or rounded marks formed by cystoliths (variously shaped calcium carbonate crystals inside epidermal cells). Inflorescences axillary or terminal, of paniculately or racemosely arranged cymes, or spikelike. Flowers bisexual or unisexual (staminate or pistillate), staminate and pistillate flowers on same or different plants; perianth hypogynous. Staminate flowers usually pedicellate; tepals 4-5, white or green; stamens 4-5, equaling tepals in number; filaments inflexed in bud, reflexing suddenly as flowers open; anthers basifixed, dehiscing by longitudinal slits; pollen ejected explosively; pistillode 1. Pistillate flowers usually sessile; tepals 2-4, hypogynous, greenish or reddish, distinct or connate; staminodes present or absent; pistil1, 1-locular; placentation basal; ovule1; style present or stigma sessile; stigma linear [capitate]; Bisexual flowers: tepals 4; stamens4; pistil1. Fruits achenes, free or loosely or tightly surrounded by persistent, accrescent perianth.

  • Provided by: [B].Flora of North America @ efloras.org
    • Source: [
    • 6
    • ]. 

    Morphology

    Seed mostly with endosperm and a straight embryo

  • Provided by: [A].Plants Of the World Online Portal - FWTA
    • Source: [
    • 2
    • ]. 

    Herbs, undershrubs, or rarely soft-wooded trees, rarely climbing, often armed with stinging hairs; epidermal cells mostly with prominent cystoliths; stems often fibrous

  • Provided by: [A].Plants Of the World Online Portal - FWTA
    • Source: [
    • 2
    • ]. 

    Petals absent

  • Provided by: [A].Plants Of the World Online Portal - FWTA
    • Source: [
    • 2
    • ]. 

    Male flowers with a 4–5-lobed calyx, lobes imbricate or valvate

  • Provided by: [A].Plants Of the World Online Portal - FWTA
    • Source: [
    • 2
    • ]. 

    Flowers very small, unisexual, usually cymose, sometimes crowded on a common enlarged receptacle

  • Provided by: [A].Plants Of the World Online Portal - FWTA
    • Source: [
    • 2
    • ]. 

    Leaves alternate or opposite, simple; stipules present or absent

  • Provided by: [A].Plants Of the World Online Portal - FWTA
    • Source: [
    • 2
    • ]. 

    Female calyx like that of the male, often enlarged in fruit

  • Provided by: [A].Plants Of the World Online Portal - FWTA
    • Source: [
    • 2
    • ]. 

    Staminodes scale-like or absent

  • Provided by: [A].Plants Of the World Online Portal - FWTA
    • Source: [
    • 2
    • ]. 

    Stamens as many as and opposite the calyx-lobes; filaments inflexed in bud; anthers 2-celled

  • Provided by: [A].Plants Of the World Online Portal - FWTA
    • Source: [
    • 2
    • ]. 

    Rudimentary ovary usually present

  • Provided by: [A].Plants Of the World Online Portal - FWTA
    • Source: [
    • 2
    • ]. 

    Ovary free or adnate to the calyx, 1-celled; style simple; ovule solitary, erect

  • Provided by: [A].Plants Of the World Online Portal - FWTA
    • Source: [
    • 2
    • ]. 

    Fruit a dry achene or fleshy drupe

  • Provided by: [A].Plants Of the World Online Portal - FWTA
    • Source: [
    • 2
    • ]. 

    Leaves alternate or opposite, sometimes anisophyllous, petiolate or sessile; stipules usually present, lateral or often intrapetiolar, often fused; lamina simple or 3–5(–7)-lobed, margin entire or variously dentate, usually with 3 subequal nerves from the base, the basal pair of nerves reaching towards the leaf-apex, the other lateral nerves usually weaker and shorter, cystoliths usually clearly visible in the epidermis of the upper surface

  • Provided by: [D].Plants Of the World Online Portal - FTEA
    • Source: [
    • 3
    • ]. 

    Inflorescences very varied, mostly pedunculate, lax or condensed racemes, often with flowers in small cymose glomerules, or sessile and condensed cymes in leaf-axils, partial inflorescences often subtended by involucral bracts, the inflorescence-axis sometimes flattened into a disc-shaped, ± fleshy receptacle

  • Provided by: [D].Plants Of the World Online Portal - FTEA
    • Source: [
    • 3
    • ]. 

    Flowers minute, unisexual or rarely bisexual, actinomorphic or (especially in ? flowers) zygomorphic, with single whorl of tepals or rarely the ? flowers naked, pedicel often articulated below perianth

  • Provided by: [D].Plants Of the World Online Portal - FTEA
    • Source: [
    • 3
    • ]. 

    Male flowers with (l–)2–5(–6) tepals, free or connate in lower half; stamens equalling tepals in number or solitary, always inflexed in bud; rudimentary ovary often present

  • Provided by: [D].Plants Of the World Online Portal - FTEA
    • Source: [
    • 3
    • ]. 

    Female flowers with 3–5 tepals, free or ± completely united, often very unequal, often accrescent after pollination, rarely rudimentary or completely absent; staminodes, if present, rudimentary or scale-like and important for the dispersal of the fruit (ejecting the achene when reflexing); ovary superior, usually laterally compressed, often oblique or asymmetrical, unilocular, unicarpellate, placentation basal, with 1 erect ovule; stigma capitate, penicillate or filiform, linear

  • Provided by: [D].Plants Of the World Online Portal - FTEA
    • Source: [
    • 3
    • ]. 

    Fruit an achene, sometimes enclosed by persistent accrescent perianth which may become fleshy

  • Provided by: [D].Plants Of the World Online Portal - FTEA
    • Source: [
    • 3
    • ]. 

    Herbs, shrubs, lianas or small trees, monoecious, dioecious or rarely polygamous, some genera with stinging hairs, but also frequently with stiff non-stinging hairs, which may be curled or sharply hooked; usually with punctiform, elongated or linear cystoliths in epidermal cells

  • Provided by: [D].Plants Of the World Online Portal - FTEA
    • Source: [
    • 3
    • ]. 

    Inflorescences are extremely varied, mostly cymose, often of densely clustered flowers, and subtended by involucral bracts; occasionally the inflorescence axis is contracted into a flattened, disk-shaped, fleshy receptacle

  • Provided by: [C].Plants Of the World Online Portal - FZ
    • Source: [
    • 4
    • ]. 

    Flowers minute, unisexual, actinomorphic or (especially the female flowers) zygomorphic, with one whorl of tepals or rarely the female flowers naked, sessile or pedicellate, pedicel often articulated just below the perianth

  • Provided by: [C].Plants Of the World Online Portal - FZ
    • Source: [
    • 4
    • ]. 

    Male flowers with (1)2–5 tepals; stamens equal in number and opposite the tepals or solitary, inflexed in bud until reflexing suddenly to forcibly eject the pollen; anthers 2-thecous opening by longitudinal slits; rudimentary ovary usually present

  • Provided by: [C].Plants Of the World Online Portal - FZ
    • Source: [
    • 4
    • ]. 

    Female flowers with 3–5 tepals, which are free or united, often very unequal, often accrescent after pollination, rarely absent; staminodes, when present, scale-like, inflexed (sometimes actively ejecting the achene when ripe); ovary superior, syncarpous, erect, usually somewhat laterally compressed, symmetrical or asymmetrical, glabrous, 1-celled, with 1 erect basal ovule (placenta absent or very small); style usually absent or very short; stigma capitate, brush-like, or linear

  • Provided by: [C].Plants Of the World Online Portal - FZ
    • Source: [
    • 4
    • ]. 

    Fruit an achene, consisting of the hardened ovary-wall, often enclosed by the persistent accrescent perianth

  • Provided by: [C].Plants Of the World Online Portal - FZ
    • Source: [
    • 4
    • ]. 

    Seed with a thin membranaceous testa, usually not fused to the endocarp, mostly with little or no endosperm, and the cotyledons correspondingly swollen and fleshy

  • Provided by: [C].Plants Of the World Online Portal - FZ
    • Source: [
    • 4
    • ]. 

    Cystoliths (incrustations of calcium or cellulosis most easily visible in dried material) are generally present in the epidermal cells, dot-like, elongated, or linear

  • Provided by: [C].Plants Of the World Online Portal - FZ
    • Source: [
    • 4
    • ]. 

    Leaves alternate or opposite, petiolate or sessile, sometimes the opposite leaves are anisophyllous with each of a pair of leaves unequal in shape and/or size; stipules usually present, lateral or often intrapetiolar, often fused; lamina simple to deeply 3–5-lobed, rarely 7-lobed, margin entire, serrate or dentate, usually strongly 3-nerved from the base with much smaller lateral nerves from the midnerve, or sometimes evenly penninerved

  • Provided by: [C].Plants Of the World Online Portal - FZ
    • Source: [
    • 4
    • ]. 

    Annual or perennial herbs, shrubs, lianas, or small trees with soft wood; monoecious or dioecious (rarely polygamous); stinging hairs are present in some genera while stiff, non-stinging hairs (without bulbous tip, sack-like base and irritating fluid) are frequent

  • Provided by: [C].Plants Of the World Online Portal - FZ
    • Source: [
    • 4
    • ]. 

    Stinging hairs are large, unicellular and have a calcified wall, bulbous tip, and a soft-walled, sack-like lower part; the bulbous tip is easily detached, liberating an irritating fluid from the sack-like part; the sack-like base of the stinging hairs is embedded in, or occasionally mounted on, a small epidermal protuberance on stems, petioles or inflorescences, see Tab. 23

  • Provided by: [C].Plants Of the World Online Portal - FZ
    • Source: [
    • 4
    • ]. 

    Herbes , arbustes, lianes ou petits arbres, monoïques ou dioïques, sans latex, à cystolithes, pourvus souvent de poils urticants, à feuilles simples, alternes ou opposées, stipulées, souvent trinerves.'Fleurs'1-sexuées, rarement ☿, réunies en cymes souvent contractées, groupées en panicules, en épis ou en capitules; périgone ♂ (ou ☿), en général actinomorphe, à 4-5, rarement 3 segments, parfois en forme de cornet; étamines 4-5 (ou 3) opposées aux segments, parfois 1 seule, à filaments recourbés vers l'intérieur dans le bouton, se redressant brusquement au moment de l'anthèse, avec projection du pollen; ovaire avorté ordinairement bien apparent; périgone ♀ souvent très différent du ♂, à segments inégaux libres, ou soudés entre eux à la base ou réunis en un tube ou un utricule enveloppant l'ovaire, parfois nul; ovaire ovoïde ou lenticulaire, dressé ou réfléchi, surmonté d'un seul stigmate couvert de papilles souvent très longues; ovule dressé, orthotrope.'Fruit : akène ou drupe, souvent enveloppé du périgone accrescent, sec ou charnu.\n\t\t\tFamille comportant environ 40 genres et près de 1000 espèces, nombreuses surtout dans les pays chauds; au Congo belge, 13 genres et 43 espèces, dont 5 ou 6 douteuses ou mal connues.\n\t\t\tLa presque totalité des Urticacées congolaises existe dans l'Est de la Colonie, spécialement dans le District des Lacs Édouard et Kivu et la partie limitrophe du District Forestier Central; beaucoup même ne se trouvent que dans cette région (genres'Pilea, Elatostema, Parietaria, Droguetia ) et, la plupart, à des altitudes comprises entre 1500 et 2500 m; les'Parietaria'dépassent 3000 m et seul'P. ruwenzoriensis atteint l'étage alpin. Le Mayumbe, le Bas-Congo et le Kasai, au contraire, n'en comptent que six dont Urera cameroonensis à très vaste distribution et les ubiquistes cités plus bas.\n\t\t\tQuant à leur distribution en Afrique, on constate, abstraction faite des espèces douteuses, que sur les 38 Urticacées congolaises, 17 sont des espèces guinéennes dont 10 atteignent l'Angola, 11 s'étendent jusqu'au Kenya et au Territoire du Tanganyika et 2 ( Boehmeria et Procris) gagnent l'Asie tropicale et la Malaisie. C'est cependant avec l'Afrique orientale que les rapports sont les plus étroits : 27 de nos espèces s'y retrouvent dont 8 atteignent l'Abyssinie et une (Droguetia iners), l'Arabie et les Indes.\n\t\t\tLa famille est remarquable par l'uniformité du port (type urticoïde) à travers de nombreux genres, et sa systématique en est d'autant plus difficile que les fleurs sont extrêmement petites et presque toujours diclines, et qu'il existe une grande variabilité des organes végétatifs. Chez beaucoup d'espèces congolaises, la répartition des sexes (monœcie, diœcie, polygamie) et la place où apparaissent, chez les espèces monoïques, les fleurs ♂ et ♀, sont mal connues et devraient être étudiées sur le vif, ainsi que la succession dans le temps des fleurs des deux sexes (protandrie, protogynie? et la prédominance numérique, parfois étrangement marquée, de l'un ou l'autre.\n\t\t\tLes Urticacées jouent un rôle assez secondaire dans la végétation congolaise : certaines (genre'Urera ) sont des lianes ne comptant ni parmi les plus communes, ni parmi les plus puissantes; d'autres, les plus nombreuses, sont des éléments assez constants du sous-bois des forêts hygrophiles, plus rarement des épiphytes (genres'Pilea, Elatostema, Laportea, Procris, Droguetia ), d'autres enfin sont remarquablement ubiquistes ( Boehmeria , certains'Fleurya ) et quelques-unes sont devenues des « mauvaises herbes » extrêmement répandues dans les stations modifiées par l'homme, avec un caractère rudéral et nitrophile parfois très marqué ( Fleurya aestuans'et'Pouzolzia guineensis'partout,'Girardinia'et'Urtica dans l'Est).\n\t\t\tAu point de vue éthologique, il faut signaler la dispersion explosive du pollen par la détente brusque des étamines au moment de l'anthèse, remarquable surtout chez'Fleurya podocarpa . La dissémination des akènes se fait mécaniquement, dans les genres'Pilea'et'Elatostema , par la détente des staminodes recourbés et engagés en dessous du fruit, alors que celle des Urera est assurée par les oiseaux qu'attire le périgone accrescent, devenu charnu et d'un rouge vif à la maturité de l'akène. Chez'Fleurya podocarpa , au contraire, il y a géocarpie, une partie des akènes se produisant sur les rhizomes. Mais la particularité la plus remarquable des Urticacées réside dans les poils urticants spéciaux à la tribu des Urereae : tantôt très abondants, tantôt très rares et localisés sur les inflorescences, ils sont dans quelques-unes de nos espèces ( Urtica, Laportea, Girardinia ) assez robustes pour traverser les vêtements et assez toxiques pour causer de durables malaises : de telles orties rendent très pénible la traversée des forêts où, comme dans certaines vallées du Ruwenzori, elles forment un épais sous-bois.

  • Provided by: [F].Flore d'Afrique Centrale
    • Source: [
    • 8
    • ]. 

    Literature

    SELECTED REFERENCES

    Bassett, I. J., C. W. Crompton, and D. W. Woodland. 1974. The family Urticaceae in Canada. Canad. J. Bot. 52: 503-516. I. Friis. 1993. Urticaceae. In: K. Kubitzki et al., eds. 1990+. The Families and Genera of Vascular Plants. 2+ vols. Berlin etc. Vol. 2, pp. 612-630. Kingsbury, J. M. 1964. Poisonous Plants of the United States and Canada. Englewood Cliffs. Miller, N. G. 1971. The genera of the Urticaceae in the southeastern United States. J. Arnold Arbor. 52: 40-68. Weddell, H. A. 1856. Monographie de la Famille des Urticacées. Paris. Woodland, D. W. 1989. Biology of temperate Urticaceae (nettle family). In: P. R. Crane and S. Blackmore, eds. 1989. Evolution, Systematics, and Fossil History of the Hamamelideae. 2 vols. Oxford. Vol. 2, pp. 309-318. [Syst. Assoc. Special Vol. 40A, B.]

  • Provided by: [B].Flora of North America @ efloras.org
    • Source: [
    • 6
    • ]. 

    Other Local Names

    NameLanguageCountry
    Nettle Family

     Information From

    Plants Of the World Online Portal - FWTA
    https://www.kew.org/science/who-we-are-and-what-we-do/strategic-outputs-2020/plants-of-the-world-online
    http://www.plantsoftheworldonline.org/terms-and-conditions
    • A The Trustees of the Royal Botanic Gardens, Kew
    Flora of North America @ efloras.org
    http://www.efloras.org/flora_page.aspx?flora_id=1
    'Flora of North America @ eFloras (2008). Published on the Internet http://www.efloras.org/flora_page.aspx?flora_id=1 [accessed August 2016]' Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
    • B Flora of North America Association
    Plants Of the World Online Portal - FZ
    https://www.kew.org/science/who-we-are-and-what-we-do/strategic-outputs-2020/plants-of-the-world-online
    http://www.plantsoftheworldonline.org/terms-and-conditions
    • C
    Plants Of the World Online Portal - FTEA
    https://www.kew.org/science/who-we-are-and-what-we-do/strategic-outputs-2020/plants-of-the-world-online
    http://www.plantsoftheworldonline.org/terms-and-conditions
    • D
    Flora Of CHina @ efloras.org
    http://www.efloras.org/flora_page.aspx?flora_id=2
    'Flora of China @ eFloras (2008). Published on the Internet http://www.efloras.org/flora_page.aspx?flora_id=2 [accessed August 2016]' Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
    • E Missouri Botanical Garden
    Flore d'Afrique Centrale
    https://www.floredafriquecentrale.be
    • F http://creativecommons.org/licenses/by/4.0/ Attribution 4.0 International (CC BY 4.0)
    Urticaceae
    • G CC0 1.0 Universal (CC0 1.0).
    World Flora Online consortium
    http://www.worldfloraonline.org/organisation/WFO
    World Flora Online Data. 2018.
    • H CC0 1.0 Universal (CC0 1.0).