Pilea

{{short description|Genus of plants}} {{Automatic taxobox | image = Pilea and Achudemia.jpg | image_upright = 1.25 | image_caption = Diversity of the genus ''Pilea'' | taxon = Pilea | authority = Lindl. (1821) | subdivision_ranks = Species | subdivision = 606; see text | subdivision_ref = <ref name = powo>[https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:331855-2 ''Pilea'' Lindl.] ''Plants of the World Online''. Retrieved 12 April 2024.</ref> | synonyms = *''Adicea'' {{small|Raf. (1824)}} *''Adike'' {{small|Raf. (1836)}} *''Chamaecnide'' {{small|Nees & Mart. ex Miq. (1853)}} *''Dubrueilia'' {{small|Gaudich. (1830)}} *''Haroldiella'' {{small|J.Florence (1997)}} *''Neopilea'' {{small|Leandri (1950)}} *''Sarcopilea'' {{small|Urb. (1912)}} *''Therebina'' {{small|Noronha (1790), nom. nud.}} |synonyms_ref = <ref name = powo/> }}

'''''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).

==Description== The majority of species are shade-loving herbaceous plants or shrubs, which are easily distinguished from other Urticaceae by the combination of opposite leaves (with rare exceptions) with a single ligulate intrapetiolar stipule in each leaf axil and cymose or paniculate inflorescences (again with rare exceptions).

==Uses== ''Pilea'' is of little economic importance; one species is used in Chinese traditional medicine (''P. plataniflora'').{{Citation needed|date=May 2019}}

===Horticulture=== Six species have horticultural value (''P. cadierei'', ''P. grandifolia'', ''P. involucrata'', ''P. microphylla'', ''P. nummulariifolia'', and ''P. peperomioides''),<ref name=RHSAZ>{{cite book|title=RHS A-Z encyclopedia of garden plants|year=2008|publisher=Dorling Kindersley|location=United Kingdom|isbn=978-1405332965|page=1136}}</ref> Some pileas are grown for their ornamental foliage which is shaped like lily-pads.<ref name="Peerless">{{cite book |last1=Peerless |first1=Veronica |title=How Not to Kill Your Houseplant |date=2017 |publisher=DK Penguin Random House |pages=108–109}}</ref>

The ASPCA includes many pilea species in the list of plants that are non-toxic to pets.<ref>{{cite web |url=https://www.aspca.org/pet-care/animal-poison-control/cats-plant-list |access-date=17 April 2021|title=Toxic and Non-Toxic Plant List - Cats }}</ref>

==Systematics== The genus has attracted little monographic attention since Weddell (1869), and the majority of taxonomic contributions have come from floristic treatments. To date, 787 species names have been published (International Plant Names Index, 2003) and estimates for the species number range from 250 to 1000.<ref>(C. D. Adams, BM, personal communication).</ref> Based on previous floristic treatments, about 30% of the species from regions not yet covered by contemporary floristic treatments may be undescribed.

The genus name ''Pilea'' is Latin for "felt cap", a reference to the calyx covering the achene.<ref>{{cite web|url=http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=125428 |title=Pilea in Flora of North America @ |publisher=Efloras.org |date= |accessdate=2022-05-01}}</ref>

==Selected species== {{Main|List of Pilea species|l1=List of ''Pilea'' species}} {{div col|colwidth=20em}} *''Pilea cadierei'' — aluminium plant *''Pilea cataractae'' *''Pilea cavernicola'' *''Pilea crassifolia'' *''Pilea depressa'' *''Pilea elegans'' *''Pilea fontana'' *''Pilea glaucophylla'' *''Pilea grandifolia'' *''Pilea involucrata'' — friendship plant *''Pilea jamesonia'' *''Pilea laevicaulis'' *''Pilea microphylla'' — artillery plant, gunpowder plant *''Pilea mollis'' — Moon Valley plant *''Pilea myriophylla'' *''Pilea napoana'' *''Pilea nummulariifolia'' — creeping Charlie *''Pilea peperomioides'' — Chinese money plant, missionary plant *''Pilea pollicaris'' *''Pilea pumila'' — Canadian clearweed *''Pilea repens'' — black-leaf panamiga *''Pilea riopalenquensis'' *''Pilea schimpfii'' *''Pilea selbyanorum'' *''Pilea serpyllacea'' *''Pilea serratifolia'' *''Pilea spruceana'' *''Pilea topensis'' *''Pilea trianthemoides'' *''Pilea trichosanthes'' *''Pilea trilobata'' *''Pilea tungurahuae'' *''Pilea victoriae'' {{div col end}}

==Fossil record== The fossil species †''Pilea cantalensis'' was widely distributed in Europe and West Siberia during the Miocene and Pliocene. It is related to the East Asian ''Pilea mongolica'' and to the North American ''Pilea pumila''.<ref>Łańcucka-Środoniowa M.: Macroscopic plant remains from the freshwater Miocene of the Nowy Sącz Basin (West Carpathians, Poland) [Szczątki makroskopowe roślin z miocenu słodkowodnego Kotliny Sądeckiej (Karpaty Zachodnie, Polska)]. Acta Palaeobotanica 1979 20 (1): 3-117.</ref>

==References==

*{{cite book |last1=Britton |first1=N.L. |last2=Brown |first2=A. |title=An Illustrated Flora of the Northern United States and Canada |url=https://archive.org/details/illustratedflora702brit |url-access=registration |publisher=Dover |year=1913 |isbn=978-0-486-22642-2 |pages=[https://archive.org/details/illustratedflora702brit/page/634 634] }} *{{cite book |last1=Fouler Rhoads |first1=A. |last2=Block |first2=T.A. |title=The Plants of Pennsylvania |publisher=University of Pennsylvania Press |year=2000 |isbn=978-0-8122-3535-7 |page=694 }} *Hortus Third, pages 872-873 *{{harvnb|Monro|2006}} *{{cite journal |first=A.K. |last=Monro |title=A new species of ''Pilea''(Urticaceae) from the Talamanca Mountains, Costa Rica |journal=Phytotaxa |volume=2 |pages=24–28 |year=2009 |doi=10.11646/phytotaxa.2.1.4 |bibcode=2009Phytx...22.1.4M |url=https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.2.1.4|doi-access=free }} *{{cite book |last1=Strausbaugh |first1=P.D. |last2=Core |first2=E.L. |title=Flora of West Virginia |publisher=Seneca Books |edition=2nd |year=1964 |isbn=978-0-89092-010-7 |pages=318–9 }} *{{cite book |first=H.A. |last=Weddell |chapter=Pilea |editor-first=A. |editor-last=De Candolle |title=Prodromus systematis naturalis regni vegetabilis |publisher=Victoris Masson |location=Paris |year=1869 |volume=16 |pages=104–163 }} *[https://plants.usda.gov/java/profile?symbol=PIIN6 USDA U.S. Dept. of Agriculture Plants Database]

==Further reading== *{{cite journal |first=C.J. |last=Chen |title=A monograph of ''Pilea'' (Urticaceae) in China |journal=Bull. Bot. Res. |volume=2 |pages=1–132 |year=1982 }} *{{cite journal |first=A.K. |last=Monro |title=The revision of species-rich genera: a phylogenetic framework for the strategic revision of ''Pilea'' (Urticaceae) based on cpDNA, nrDNA, and morphology |journal=Am. J. Bot. |volume=93 |issue= 3|pages=426–441 |year=2006 |doi=10.3732/ajb.93.3.426 |pmid=21646202 |bibcode=2006AmJB...93..426M |doi-access=free }}

Category:Pilea Category:Urticaceae genera Category:Taxa named by John Lindley