A delicate umbellifer typically found growing in ponds and ditches with low nutrient water.
Tubular Water-dropwort grows in a variety of forms depending on local conditions and management practices. It often occurs as small low-growing plants only a few cm high, with a rather cow-parsley-like basal leaf (basal leaves grow at the bottom of the stem) and may also have finely divided submerged leaves. Flowering plants are easy to identify but seedling or non-flowering plants can be tricky. Therefore it is easier to identify and record abundance once the plants reach maturity. The characteristic stem and stem leaves of Tubular Water-dropwort, typically develop when the plants are older. Mature, flowering, plants can sometimes be surprisingly tall: over 1m in height. Where they grow in amongst other tall wetland species their stems are sometimes lax and scrambling, and they often fall over as the stems are quite weak. Later in the season, the flowers develop distinctive rounded fruiting heads.
Tubular Water-dropwort is a lowland plant which grows in a wide range of wetland areas, including damp ground on the edges of ponds (more rarely rivers, streams, canals, ditches and lakes) as well as in dense wetland vegetation in meadows, marshes, fens and pasture on river floodplains and occasionally in deep water in permanent ditches. It appears most frequently in ancient habitats, where there is a long history of stable land use, such as traditionally managed pasture and meadows.
Tubular Water-dropwort often forms long-lived populations. These can occur in a surprising variety of habitats; from open muddy areas at the edge of ponds to amongst dense vegetation such as sedges and rushes in the drawdown zone. It can form very low-growing plants in mown grassland and will occasionally persist on seasonally inundated tracks, although these plants rarely flower. A unifying requirement for these habitats is clean water with little or no nutrient pollution from intensive agriculture. This is because nutrients are a fertilizer that allows more vigorous and fast growing species to out compete more delicate species such as Tubular-Water Dropwort.
To germinate, Tubular Water-dropwort requires some kind of disturbance to create openings amongst denser vegetation. Consequently it favours habitat with both grazing and fluctuating water levels, both of which help eliminate competing plants and maintain appropriate conditions. Although usually found in open sunny situations and is intolerant of heavy shading from trees and scrub, light shade can sometimes help to knock-back Tubular Water-dropwort’s competitors, allowing it better opportunities to flourish.
This perennial plant flowers between July and September. It reproduces by seeds and small plantlets that develop from it’s spreading root-like stolons. Both can be transported by flood water and animals.
Distribution and threats
Tubular Water-dropwort is classed as Vulnerable in the UK and protected as a 41/42 Priority Species in both Wales and England.
Tubular Water-dropwort has declined dramatically in the UK since the 1950s. This has been due to multiple factors including wetland drainage, nutrient enrichment, loss of grazing, land use change to intensive agriculture and grazing, and the spread of non-native species. It is still found in southern England and in places on the coast of Wales, it is a rapidly declining plant. Recent surveys, conducted through PondNet, have found it has been lost from a high proportion of its previous sites.