Adder’s-tongue spearwort Ranunculus ophioglossifolius

Status Amber - Vulnerable and Near-Threatened
Best Time to See May, June, July, August, September
Colour Yellow, Orange
Habitat Wetland

A pretty plant with small, bright yellow buttercup-like flowers. The leaves are pointed oval, quite unlike ordinary buttercup leaves. When submerged, the pale greenish-yellow leaves float to the surface like small water-lily leaves.

Distribution

It used to grow in parts of southern England and has always been rather rare, but is now found at only two sites in Gloucestershire. The largest surviving population is at Badgeworth (hence the alternative name for it: the 'Badgeworth buttercup') in East Gloucestershire and has been dependent on management since 1962. With appropriate human disturbance a sizeable population of plants flower and fruit every year. A nearby smaller site, Inglestone Common, is still managed by grazing, and that population is more erratic. It is at the northern edge of its range in Britain.

Habitat

Wet or marshy places, often round the edges of field ponds. It prospers at the edge of cattle ponds in the churned-up mud. It requires low competition and quite a specialised lowland habitat with winter inundation, reduced summer water levels and bare, wet mud for seedling establishment from August to October. Enough rain to fill pools with water and submerge plants in early winter is essential to protect the seedlings, as is freedom from frosts hard enough to freeze pools solid and kill the growing tips of plants. The substrate is base-rich Lias clay at the two extant sites.

Status

Classified as Vulnerable and protected under Schedule 8 of the Wildlife and Countryside Act 1981, perhaps unsurprising given its exceedingly finicky requirements.

Key threats

It is mainly threatened by loss of grazing on pastures and commons, loss of muddy ponds, or overgrazing and excessive trampling too early in the year. Climate change with drier winters also causes drying out of small ponds. Without a mild, frost-free Autumn and enough rain to keep the ground moist for seedlings to develop, they can be uprooted by birds or killed by trampling livestock.

Did you know?

The Latin name Ranunculus means 'froglike', referring to the plant's preference for aquatic habitats. The specific part of the scientific name, ophioglossifolius refers to the shape of the leaves that resemble the small fern Ophioglossum.