GREATER WATER PARSNIP is one of Britain’s most threatened plants, categorised as Endangered in the Red List of flowering plants. It’s a tall, imposing umbellifer – a member of the carrot family with distinct ‘umbrella’ flowers – which likes to keep its feet wet. Once widespread in lowland wetlands and river floodplains, Greater Water Parsnip was recorded from the River Foss as long ago as 1796 and remained widespread from York to Strensall into the early 20th century. According to Henry Baines’ Flora of Yorkshire, published in 1840, it also grew “in the moat at York”.
Drainage of wetlands, over-engineering of rivers and the mechanisation of ditch management have been disastrous for this plant, to the point where it has disappeared from most of its British range. Two beetles dependent on Greater Water Parsnip have become extinct in Britain. In Yorkshire it survives only in the Lower Derwent Valley (mainly around Bubwith and North Duffield) and in a small area beside Hornsea Mere, with occasional plants seen on the Leven Canal.
Greater Water Parsnip is not difficult to grow from seed and a number of re-introductions have been attempted in Yorkshire but most of these have been poorly monitored and the plants have vanished without trace (Yorkshire Water’s excellent Tophill Low Nature Reserve in the Hull valley being a notable exception). Little is known about how long individual plants live and whether they reproduce from seed or by vegetative means. We know its natural habitat is tall reedbed or fen vegetation but we don’t know how much competition it can tolerate, or what kind of management is most beneficial. To try and answer some of these questions, three plants grown from Yorkshire seed have been planted in the Water Vole Scrape at Rawcliffe Meadows. This is not a re-introduction project – the site is not big enough for that – but it’s well suited to monitoring the life-history of the plants. Initial results show that conditions are favourable with all three flowering and producing seed since they were planted out in June.
M.Hammond, October 2017
Which are the beetles which used to depend on it? Here in Oxon we have found that it is capable of significant vegetative reproduction from its roots. Whole plants can result just from root cuttings. Our Botanic Garden in Oxford is propagating from seed and from root cuttings to plant out in new trial sites.
According to our ecologist, Martin Hammond, the beetles are the weevils Lixus paraplecticus and Hypera arundis. It is good to hear that propagation work is being carried out on multiple sites.