Information on Lesser Spearwort

Common Name: Lesser Spearwort
Scientific Name: Ranunculus flammula
Irish Name: Glasair léana bheag
Family Group: Ranunculaceae
Distribution: View Map (Courtesy of the BSBI)
Flowering Period


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Lesser Spearwort is not easily confused with other wild plants on this web site.


This hairless perennial is usually found in still or slow-moving water such as lake margins, marshes and wet places.  It reaches up to 50cm high, carrying shiny yellow 5-petalled flowers (7-20mm across) on reddish, furrowed stems. These flowers bloom from May to September and are more often solitary. The basal leaves are oval, the stem leaves spear-shaped and usually untoothed. The fruits are heads of achenes on erect stalks.  This native plant is very poisonous, and it belongs to the family Ranunculaceae.  

First recorded in 1976 at Vartry Reservoir, Roundwood, Co Wicklow and photographed at Tacumshane Lake, Co Wexford in 2007. 

If you are satisfied you have correctly identified this plant, please submit your sighting to the National Biodiversity Data Centre

Spearwort, Lesser
Spearwort, Lesser

This plant is frequently grown in garden ponds as it is less invasive than its larger cousin, Greater Spearwort.