{{Short description|Genus of flowering plants}} {{redirect|Redvine|other meanings|red vine (disambiguation){{!}}red vine}} {{Speciesbox |image = Brunnichia_ovata.jpg |image_caption = ''Brunnichia ovata'' tendrils |genus = Brunnichia |parent_authority = Banks ex Gaertn. |species = ovata |authority = (Walter) Shinners |synonyms = *''Rajania'' {{small|Walter}} *''Brunnichia cirrhosa'' {{small|Gaertn.}} *''Fallopia cirrhosa'' {{small|(Gaertn.) Hofer ex M.Gómez}} *''Polygonum claviculatum'' {{small|Meisn.}} *''Rajania caroliniana'' {{small|J.F.Gmel.}} *''Rajania ovata'' {{small|Walter (1788)}} (species basionym) |synonyms_ref = <ref name = powo>{{cite web |title=''Brunnichia'' Banks ex Gaertn. |url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:32437-1 |website=Plants of the World Online |publisher=Royal Botanic Gardens, Kew |access-date=25 October 2025}}</ref><ref name = powo1>{{cite web |title=''Brunnichia ovata'' (Walter) Shinners |url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:37576-2 |website=Plants of the World Online |publisher=Royal Botanic Gardens, Kew |access-date=25 October 2025}}</ref> }}

'''''Brunnichia''''' is a genus of flowering plants in the family Polygonaceae. It includes a single species, '''''Brunnichia ovata''''', commonly known as '''redvine''',<ref>{{cite web |title=Brunnichia ovata - Species Page - APA: Alabama Plant Atlas |url=http://floraofalabama.org/Plant.aspx?id=2916 |website=floraofalabama.org}}</ref> '''American buckwheat vine'''<ref>{{cite web|url=https://plants.usda.gov/plant-profile?symbol=BROV4|title=Plants Profile for Brunnichia ovata (American buckwheat vine)|website=plants.usda.gov}}</ref> or '''ladies' eardrops''', a woody vine native to the central and southeastern United States.<ref name = powo1/>

==Description== ''Brunnichia ovata'' is made up of an alternate leaf arrangement of its simple leaves. It is regarded as deciduous and the blades of its leaves are ovate or having an oval shape. Its leaves can range anywhere from 2 to 5 inches in length and its petioles are usually short. The flowering of the ''Brunnichia ovata'' species is typically seen from June to July and they are greenish in color. The fruit of the species is coined by its common name, “ear-drops” due to its appearance of hanging earrings. The stems shows proximal portions to be woody and the distal portions of the shoots to be herbaceous. Hence the species is regarded as a semi-woody vine.<ref>{{cite web |title=Louisiana Plant ID {{!}} Brunnichia ovata (ladies' ear-drops) |url=http://www.rnr.lsu.edu/plantid/species/leardrops/leardrops.htm |website=www.rnr.lsu.edu}}</ref> The optimum temperature found for germination of the species is 35&nbsp;°C in both soil and Petri dishes. Below or above, 25&nbsp;°C and 40&nbsp;°C, respectively will yield no germination or emergence.<ref>{{cite journal|title=Redvine (Brunnichia ovata) Germination and Emergence|journal = Weed Science|volume = 39|last1=Shaw|first1=David R.|last2=Mack|first2=Robert E.|pages=33–36|language=en|doi=10.1017/S0043174500057829|last3=Smith|first3=Clyde A.|year = 1991}}</ref> Furthermore it requires altitude ranges of 0 to 200 meters and can grow up to 40 feet tall.<ref>{{cite web|url=http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=242416200|title=Brunnichia ovata in Flora of North America @ efloras.org|website=www.efloras.org}}</ref>

==Geographic distribution== ''Brunnichia ovata'' is a native vine to North America. It is native to coastal plains of the south-central and southeastern United States, ranging from Texas to Alabama, as far north as southern Illinois, and eastward to Georgia.<ref>{{cite web |title=Louisiana Plant ID {{!}} Brunnichia ovata (ladies' ear-drops) |url=http://www.rnr.lsu.edu/plantid/species/leardrops/leardrops.htm |website=www.rnr.lsu.edu}}</ref> Plants grow near riverbanks, the perimeters of lakes, wet woods and thickets.<ref>{{cite web|url=http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=242416200|title=Brunnichia ovata in Flora of North America @ efloras.org|website=www.efloras.org}}</ref>

==Uses== Redvine is a native species to the US and a favored plant for honey production by beekeepers. <ref>url=https://nature.mdc.mo.gov/discover-nature/field-guide/ladies-eardrops {{Webarchive|url=https://web.archive.org/web/20190109063956/https://nature.mdc.mo.gov/discover-nature/field-guide/ladies-eardrops |date=2019-01-09 }}</ref> In January 2019, the largest honey producer in Arkansas announced they were closing production due to damage to native wildflowers from the herbicide Dicamba, and possibly relocating to Mississippi. Redvine was specifically cited by the owner of Crooked Creek Bee Company as an example of native vegetation being destroyed leading to an inferior product. <ref>url=https://www.arkansaspublicmedia.org/post/dicamba-concerns-end-beekeepers-retail-operations {{Webarchive|url=https://web.archive.org/web/20190109062959/https://www.arkansaspublicmedia.org/post/dicamba-concerns-end-beekeepers-retail-operations |date=2019-01-09 }}</ref>

Redvine species are a pest when they grow within crops; for example, ''Brunnichia ovata'' is a significant problem in soybean crops in the Mississippi Delta.<ref>{{Cite journal | doi = 10.1614/WT-03-234R1| title = Redvine (Brunnichia ovata) and Trumpetcreeper (Campsis radicans) Management in Glufosinate- and Glyphosate-Resistant Soybean1| journal = Weed Technology| volume = 18| issue = 4| pages = 1058| year = 2004| last1 = Reddy| first1 = Krishna N.| last2 = Chachalis| first2 = Demosthenis| s2cid = 31699249| url = https://naldc-legacy.nal.usda.gov/naldc/download.xhtml?id=40864&content=PDF| url-access = subscription}}{{dead link|date=June 2025|bot=medic}}{{cbignore|bot=medic}}</ref> It is an example for thigmotropism. Usually thigmotropism occurs when plants grow around a surface, such as a wall, pot, or trellis. Climbing plants, such as vines, develop tendrils that coil around supporting objects. Touched cells produce auxin and transport it to untouched cells. Some untouched cells will then elongate faster so cell growth bends around the object. Some seedlings also exhibit triple response, caused by pulses of ethylene which cause the stem to thicken and curve to start growing horizontally.

==Taxonomy== The species was first described as ''Rajania ovata'' by Thomas Walter in ''Flora Caroliniana'' in 1778. It was reassigned from the genus ''Rajania'' to ''Brunnichia'' by Lloyd Shinners in the publication ''Sida'' in 1967.<ref name = powo1/>

==References== {{Reflist}}

{{Taxonbar|from=Q4979104|from2=Q15585898}}

Category:Polygonaceae Category:Monotypic Polygonaceae genera Category:Flora of Alabama Category:Flora of Arkansas Category:Flora of Florida Category:Flora of Georgia (U.S. state) Category:Flora of Illinois Category:Flora of Kentucky Category:Flora of Louisiana Category:Flora of Mississippi Category:Flora of Missouri Category:Flora of Oklahoma Category:Flora of South Carolina Category:Flora of Tennessee Category:Flora of Texas Category:Taxa named by Joseph Banks Category:Taxa named by Joseph Gaertner

{{Polygonaceae-stub}}