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Urtica australis

Interesting Facts

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Description

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Family Urticaceae

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 .

About 47 genera and 1300 species: most numerous in wet tropical regions , extending into temperate regions ; 25 genera and 341 species (163 endemic, one introduced ) in China.

Plants in this family have numerous uses. The stem fiber of some genera and species is of high quality and used to make cloth, fishing nets , and ropes and for some industrial materials . In central and southern China,

Boehmeria nivea is widely cultivated for ramie fiber and Girardinia diversifolia subsp. triloba is widely cultivated for  red huo ma  fiber. Boiled young shoots of Girardinia, Laportea, and Urtica are eaten as vegetables. Some species are used in local Chinese medicine. Pellionia repens, Pilea cadierei, P. microphylla, and P. peperomioides, among other species, are widely cultivated as ornamentals in China and elsewhere. Some genera, such as Elatostema, Pellionia, and Pilea, occur frequently in shady, moist habitats of subtropical forests and become dominant elements of the forest floor vegetation. Plants of the first five genera belong to tribe Urticeae, which is usually characterized by the distinctive stinging hairs.[1]

Genus Urtica

Herbs, annual or perennial , with stinging and nonstinging hairs on same plant. Stems simple or branched, erect , ascending , or sprawling . Leaves opposite; stipules present. Leaf blades elliptic , lanceolate, ovate , or orbiculate, margins dentate to serrate; cystoliths rounded or ± elongate . Inflorescences axillary , lax , of cymes arranged in racemes or panicles. Flowers unisexual , staminate and pistillate flowers in loose to tight clusters in separate inflorescences or intermixed in same inflorescence on same or different plants ; bracts narrowly triangular to lanceolate, lacking hooked hairs. Staminate flowers : tepals 4, distinct , equal; stamens 4; pistillode cuplike. Pistillate flowers: tepals 4, distinct, inner 2 equal to achene, outer 2 smaller, without hooked hairs; staminodes absent; style absent; stigma tufted , persistent or deciduous. Achenes sessile, laterally compressed , ovoid or deltoid, loosely enclosed by inner tepals. x = 12, 13.

Species 45: nearly worldwide.[2]

Taxonomy

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Similar Species

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Members of the genus Urtica

ZipcodeZoo has pages for 18 species, subspecies, varieties, forms, and cultivars in this genus:

U. angustifolia (Narrow-Leaved Nettles) · U. ballotifolia (Nettle) · U. cannabina (Hemp Nettle) · U. chamaedryoides (Heartleaf Nettle) · U. dioica (California Nettle) · U. dioica dioica (California Nettle) · U. dioica holoserica (California Nettle) · U. dioica holosericea (California Nettle) · U. dioica subsp. gracilis (California Nettle) · U. dioica subsp. holosericea (Hoary Stinging Nettle) · U. ferox (Nettle Tree) · U. galeopsifolia (Narrow-Leaved Nettle) · U. gracilenta (Mountain Nettle) · U. hyperborea (Himalayan Nettle) · U. incisa (Scrub Nettle) · U. moluccana (Hawai'i Lopleaf) · U. pilulifera (Roman Nettle) · U. urens (Burning Nettle)

More Info

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Further Reading

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Notes

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Contributors

Identifiers

Footnotes

  1. Jiarui Chen, Prof. Qi Lin, Ib Friis, C. Melanie Wilmot-Dear & Alex K. Monro "Urticaceae". in Flora of China Vol. 5 Page 76. Published by Science Press (Beijing) and Missouri Botanical Garden Press. Online at EFloras.org. [back]
  2. "Urtica". in Flora of North America Vol. 3. Oxford University Press. Online at EFloras.org. [back]
Last Revised: 7/23/2012