Geum rivale

Geum rivale is widespread in Europe, particularly in the northern and central parts. It is found throughout the British Isles, the Faroes, Iceland, Scandinavia, the Baltic States, and much of Central Europe{{cite book| last1 = Kurtto| first1 = Arto| last2 = Lampinen| first2 = Raino| last3 = Junikka| first3 = Leo| date = 2004| title = Atlas florae Europaeae, distribution of vascular plants in Europe. 13: Rosaceae (Spiraea to Fragaria, excl. Rubus)| publisher = Committee for mapping the flora of Europe and Societas Biologica Fennica| location = Helsinki| isbn = 978-951-9108-14-8|page = 143}} (up to elevations of 2400{{nbsp}}m in the Alps and {{sigfig|2076|2}} in the Carpathians).{{cite book| last1 = Meusel| first1 = Hermann| last2 = Jäger| first2 = E.| last3 = Weinert| first3 = E.| date = 1965| title = Vergleichende Chorologie der zentraleuropäischen Flora. [Band I]| publisher = Fischer| location = Jena| at = T532, K220}}

It is absent from the Pannonian Basin and western France; on the Italian Peninsula, it is found in scattered locations in the northern and central Apennines, while on the Iberian Peninsula it is restricted between 1000 m and 2200{{nbsp}}m in the Cantabrians, Pyrenees, the Iberian and Central Systems, and the mountains of Sierra Nevada and Sierra de Cazorla in the south.{{cite book|last = Laínz| first = M.| title = Flora Iberica| volume = 6| year = 1998| chapter = Geum L.| chapter-url = http://www.floraiberica.es/floraiberica/texto/pdfs/06_087_07%20Geum.pdf| page = 80}}

It is found in the mountains of the Balkan Peninsula (in Bulgaria its altitudinal range is 1200–2100{{nbsp}}m),{{cite book| last = Asenov| first = I.| chapter = Omajniče – Geum L.| title = Flora na Narodna Republika Bǎlgarija|volume = V| year = 1973| editor-last1 = Vǎlev| editor-first1 = Stoju| editor-last2 = Asenov| editor-first2 = Ivan| place = Sofia| publisher = Bulgarian Academy of Sciences| language = Bulgarian| page = 197}} the Caucasus, northern Anatolia and north-western Iran. It is also native to northern Ukraine and the central and northern parts of European Russia, Western Siberia up to the Sayan–Angara region in the east, as well as parts of Central Asia (the Dzungaria and the Tarbagatai areas and Tian Shan).{{cite book|title = Flora SSSR| volume = 10| year = 1941| location = Moscow/Leningrad| publisher = AN SSSR| language = Russian| pages = 242–3}}

Geum rivale is also native to a broad region in Canada and the United States.{{cite web| title = Geum rivale| work = Flora of North America | publisher = eFloras.org| url = http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=200010867| access-date = 22 January 2022}}

The plant is a native perennial of slow-draining or wet soils and can tolerate mildly acidic to calcareous conditions in full sun or under partial shade. Habitats include stream sides, pond edges, damp deciduous woodland and hay meadows.{{Cite web |url=http://www.wildseed.co.uk/species/view/60 |title=Wildseeds Website. |access-date=2009-05-11 |archive-date=2015-05-25 |archive-url=https://web.archive.org/web/20150525204344/http://wildseed.co.uk/species/view/60 |url-status=dead }}

It is a component of purple moor grass and rush pastures is a type of Biodiversity Action Plan habitat in the UK. It occurs on poorly drained neutral and acidic soils of the lowlands and upland fringe. It is found throughout the British Isles with the exception of south-east England, the Western Isles of Scotland and parts of the midlands and the west country.

Geum rivale is pollinated primarily by bees, and less often by flies and beetles. As the flower matures, elongation of the stamens ensures it self-fertilises if not already cross-pollinated. The flowers' stigmas mature before the stamens. It begins flowering a little earlier than G. urbanum, so early pollinations are within the gene-pool of the single species.{{Cite web |url=http://www-biol.paisley.ac.uk/bioref/Genetics/geum.html |title=Biodiversity site. |access-date=2009-05-11 |archive-url=https://web.archive.org/web/20071202105435/http://www-biol.paisley.ac.uk/bioref/Genetics/geum.html |archive-date=2007-12-02 |url-status=dead }} The seeds of Water Avens are burr-like, and are distributed after being caught in the coats of rabbits and other small mammals,{{Cite web |url=http://www.first-nature.com/flowers/geum_rivale.asp |title=First Nature wildflowers. |access-date=2009-05-11 |archive-url=https://web.archive.org/web/20080516153340/http://www.first-nature.com/flowers/geum_rivale.asp |archive-date=2008-05-16 |url-status=dead }} and by rhizomal growth.

Geum rivale is parasitised by Podosphaera aphanis – a conidial powdery mildew.Ing, B.( 1990). An Introduction to British Powdery Mildews. Yellow spots on the living leaf may be caused by Peronospora gei – a downy mildew.Ellis, M. B. & J. P. (1997). Microfungi on Land Plants: An Identification Handbook.

Geum urbanum hybridises fairly regularly with Geum rivale as they are closely related and occur together.

In North America it is known to hybridise with Geum aleppicum (the hybrid being named Geum × aurantiacum {{au|Fries ex Scheutz}}), with Geum macrophyllum var. perincisum (as Geum × pervale), and with Geum macrophyllum var. macrophyllum (as Geum × pulchrum).

File:Geum rivale clump.jpg|Group of plants

File:Geum rivale flowers.jpg|Flowers

File:Geum rivale with pseudopeloria.jpg|Pseudo-peloric flower

File:Geum rivale - Niitvälja.jpg|Fruits

{{Reflist|32em}}

• {{Commons category-inline|Geum rivale|Geum rivale}}
• [https://www.youtube.com/watch?v=XGushUh9lhU Video and commentary on Geum urbanum and Geum rivale]
• {{PFAF|Geum rivale}}

{{Taxonbar|from=Q161625}}

rivale

Category:Plants described in 1753

Category:Taxa named by Carl Linnaeus