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Koenigia × fennica; photograph Harri Kosonen, CC BY-SA, via GBIF CC BY-SAHarri Kosonen, CC BY-SA, via GBIF

Koenigia × fennica (Reiersen) T.M.Schust. & Reveal

Finnish knotweed

Polygonaceae

A hybrid: K. alpina × K. weyrichii, the parents Kew's World Checklist states for it (WCVP, RBG Kew).

No habitat climate
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Koenigia × fennica, photograph Harri Kosonen, CC BY-SA, via GBIFKoenigia × fennica, photograph Harri Kosonen, CC BY-SA, via GBIFKoenigia × fennica, photograph Harri Kosonen, CC BY-SA, via GBIFKoenigia × fennica, photograph Harri Kosonen, CC BY-SA, via GBIF 5 photographs ›

Summary

Koenigia × fennica, known as Finnish knotweed, is a hybrid between two species of Koenigia, K. alpina and K. weyrichii, members of the family Polygonaceae, the knotweed family. It generally only known as a cultivated garden plant, but plants have been recorded a few times surviving in abandoned areas in northern Europe, especially in Finland. The cultivar 'Johanniswolke' is considered an attractive ornamental perennial plant.

Quoted from Wikipedia, "Koenigia × fennica", CC BY-SA 4.0.

Cultivation

Nothing derived: no habitat climate for this species.

Climate across the habitat

No habitat climate can be derived: Native range not verified: no WCVP distribution with native status for this name, so records cannot be told from cultivation and no habitat climate is derived. 64 of the 1578 in-range records are placed to worse than 10 km, or to no stated accuracy and fewer than three decimals or by something other than a person's observation, and cannot place a climate cell, though they count for the map and its marker.

Natural habitat

No native range: WCVP lists no region where it is native.
Openly licensed records, not tested against the stated range, framed on where they fall.
NativeWCVP lists no region where it is native; the regions it does list are named here. · introduced: Denmark, Finland, Great Britain, Norway, Sweden, Germany · regions are the level-3 units of the World Geographical Scheme for Recording Plant Distributions, as Kew's World Checklist records ranges, some under historical names such as Yugoslavia or Czechoslovakia (how).
Kew's description“perennial” · “temperate” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedNo verified native range for this name: WCVP has no entry with native status, and a checklist that only reports presence cannot tell a wild record from a garden one. The map shows 1534 openly licensed records of 1578 untested against any range; no map marker or climate is derived from them, and no sheet is built from them. 64 in-range records are placed to worse than 10 km, or with no stated accuracy (admitted only as a person's observation to three decimals), and stay on the map but off the climate.

Photographs

Koenigia × fennica, photograph 1did not loadKoenigia × fennica, photograph 2did not loadKoenigia × fennica, photograph 3did not loadKoenigia × fennica, photograph 4did not load

Photographs: Harri Kosonen, CC BY-SA, via GBIF (4).

Other Koenigia 14 in the reference

Koenigia alpina Koenigia alpina Alpine knotweed Photo: CC BY, Urgamal Magsar Koenigia angustifolia Polygonaceae Koenigia campanulata Koenigia campanulata Bellflower Knotweed Photo: CC BY, rmjb Koenigia coriaria Polygonaceae Koenigia davisiae Koenigia davisiae Davis's Knotweed Photo: CC BY, harriiKoenigia divaricata Koenigia divaricata Polygonaceae Photo: CC BY, Urgamal MagsarKoenigia islandica Koenigia islandica Iceland-purslane Photo: CC BY, Karl PalssonKoenigia jurii Koenigia jurii Juriy’s knotweed Photo: CC BY, Lena PerovaKoenigia mollis Koenigia mollis Sikkim Knotweed Photo: CC0, author not statedKoenigia panjutinii Koenigia panjutinii Polygonaceae Photo: CC BY, Oleg KosterinKoenigia phytolaccifolia Koenigia phytolaccifolia Polygonaceae Photo: CC BY, Rosie YacoubKoenigia polystachya Koenigia polystachya Himalayan knotweed Photo: CC BY, Subir B. Shakya all 15 ›

Names & registers

Also known as Aconogonon alpinum; Aconogonon xfennicum; Aconogonum xfennicum. (GBIF Backbone)

GBIFPOWOIPNIWikidataWikipedia

The record

Family
Polygonaceae
Described by
(Reiersen) T.M.Schust. & Reveal
Native to
not verified
Records
1578 georeferenced · 1534 open · range not tested

Every figure here is derived from public data by a stated rule and names its source; nothing about this species is written for its page by a person or by AI, apart from the marked, credited quotations. How →

Where this page came from built 2026-10-22
GBIF species record gbif.species answeredasked 2026-10-22
GBIF synonyms gbif.synonyms answeredasked 2026-10-22
GBIF common names gbif.vernacular answeredasked 2026-10-22names fetched 2026-10-22
WCVP native range wcvp.distribution answeredas of 2026-06-04Kew's entry lists no native region, only 6 where it is introduced
GBIF occurrence records gbif.occurrences answeredas of 2026-10-21GBIF occurrence download https://doi.org/10.15468/dl.hbdw64, of 2026-10-21; 13 records within 1 km of a botanic garden, herbarium or zoo left out (12 at a botanic garden or arboretum, 1 at a zoo; Wikidata's list)
Habitat climate climate nothing to reportasked 2026-10-22native range not verified: no WCVP distribution with native status for this name, so records cannot be told from cultivation and no habitat climate is derived
Wikidata wikidata answeredasked 2026-10-22
Wikipedia wikipedia answeredasked 2026-10-22
iNaturalist taxon inat.taxon not asked
iNaturalist photographs, wild inat.photos.wild not asked
iNaturalist photographs, cultivated inat.photos.cultivated not asked
GBIF media gbif.media answeredasked 2026-10-22
Wikimedia Commons commons nothing to reportasked 2026-10-22
OpenAlex papers openalex not askednot yet asked for this reference; a later fill takes the papers from OpenAlex's snapshot

Every source is recorded as having answered, reported nothing, refused, failed, not been asked, or answered twice where one answer is taken (“not taken: two items answered”), and, for a source asked when this page was built, when: the figures are as the source held them that day; a source read from a file (Kew's World Checklist, a GBIF download) says "as of" the file's day instead; a row carried from an earlier build of the page names that build instead. Only “nothing to report” is ever shown as an absence. Records came from 37 datasets via GBIF.org; each carries its own licence.

Cultifolio

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