Lesser Spearwort

Ranunculus flammula

- Lesser Spearwort (Ranunculus flammula)

Description/identification

Lesser Spearwort displays the characteristic shiny yellow flowers typical of buttercups. What sets it apart, however, is its distinctive narrow, spear-shaped leaves, which also inspire its common name. Lesser Spearwort can grow between 20-30 cm in height but it is also capable of spreading across the ground in a creeping manner.

The rarer Greater Spearwort (Ranunculus lingua) is a larger plant, though the two can be superficially very similar. It is also similar to the very rare Adder’s-tongue Spearwort (Ranunculus ophioglossifolius) and Creeping Spearwort (Ranunculus reptans).

Habitat

Lesser Spearwort thrives in all kinds of wetlands, avoiding only the most acidic waters. It can be found as an emergent plant in ponds and ditches, the edges of lakes, and in small streams, in wet grassland, floodplains, wet trackways, in fens and dune-slacks. It favours clean, unpolluted water with low nutrient levels. Grazing by large herbivores plays a key role in supporting this species by disturbing the ground and reducing competition from other plants, creating light and space for Lesser Spearwort to flourish.

Distribution and threats

Lesser Spearwort faces threats from poor water quality, particularly nutrient pollution, which encourages the rapid growth of larger wetland plants that can overwhelm it. Additionally, habitat loss from wetland drainage and infilling has contributed to its decline. Reduced grazing pressure and other management of wetlands continues to be a driver of loss of populations.

This species is widespread throughout Britain and Ireland and is a common plant of most of the north and west of Britain. It is much more local in central and south-eastern England due to intensive land use. There are two subspecies found in the north of Scotland and parts of Ireland that occur nowhere else in the world.