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Purple Loosestrife

Purple Loosestrife

Lythrum salicaria

Identify the Purple Loosestrife from a photo and log your finds with Florapass.

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How common: Very common

Purple Loosestrife is a tall, showy wetland plant with long spikes of purple‑pink flowers. It is native across temperate parts of Europe, Asia and North Africa, and is often seen along rivers, lakes and ditches. It is also grown in gardens with damp spots and has become invasive in North America.

Did you know?

  • Its flowers occur in three forms of different lengths, which helps prevent self‑pollination and promotes cross‑pollination.
  • In North America it is a notorious invasive and is listed among the 100 most harmful alien species.

About the species

Identification

Perennial, usually 40–120 cm tall. Stems upright, square and slightly hairy. Leaves 4–10 cm, without stalks, narrow and pointed with a rounded or heart‑shaped base; they grow mostly in pairs, sometimes in rings around the stem; edges are smooth. Many small purple‑magenta flowers form tall spikes at the stem tips; each flower is about 1 cm across with six narrow petals. Later it makes small dry seed pods packed with tiny dark seeds. Differs from rosebay willowherb: loosestrife has six petals and a square stem, not four petals and long thin pods. Flowers in Finland in July–August.

Plant group

Herbaceous plants

Habitat

shore

Flowering

Jul–Aug

About the habitat

Grows on wet ground: riverbanks, lake shores, marshy meadows, ditches and pond edges, and sometimes stands in shallow water. Also found as a garden perennial in damp places. Common in southern and central Finland; scarce in the north; absent from northern and eastern Lapland.

Sources

Photo: flamelily, CC0 1.0 https://www.gbif.org/occurrence/6131344234

Text: Pinkka: BIO-503 Suomen kasvisto ja kasvillisuus - Sisävedet: rantaniityt, CC BY 4.0 https://laji.fi/taxon/MX.39079

Text: Pinkka: Kumpulan kasvitieteellisen puutarhan maantieteellinen osasto - Suomi, CC BY 4.0 https://laji.fi/taxon/MX.39079

Text: Pinkka: Luonnonvaraiset lääkekasvit - Koppisiemeniset, CC BY 4.0 https://laji.fi/taxon/MX.39079

Text: Wikipedia (Finnish), CC BY-SA 4.0 https://fi.wikipedia.org/wiki/Rantakukka

See also